J u ly -Aug. 1981 PQLUPHONU $2 .5 0 ELECTRONIC MUSIC & HOME RECORDING ISSN: 0163-4534
GUITAR ELECTRONICS INPUT/OUTPUT STRUCTURES MODIFY: FENDER AMP MXR PHASE 100 MORE GR- 500 THE ULTIMATE KEYBOARD
The Prophet-10 is the most complete keyboard instrument available today. The Prophet is a true polyphonic programmable synthesizer with 10 complete voices and 2 manuals. Each 5 voice keyboard has its own programmer allowing two completely different sounds to be played simultaneously. All ten voices can also be played from one keyboard program. Each voice has 2 voltage controlled oscillators, a mixer, a four pole low pass filter, two ADSR envelope generators, a final VCA and independent modula tion capabilities. The Prophet-10’s total capabilities are too The Prophet-10 has an optional polyphonic numerous to mention here, but some of the sequencer that can be installed when the Prophet features include: is ordered, or at a later date in the field. It fits * Assignable voice modes (normal, single, completely within the main unit and operates on double, alternate) the lower manual. Various features of the * Stereo and mono balanced and unbalanced sequencer are: outputs * Simplicity; just play normally & record ex * Pitch bend and modulation wheels actly what you play. * Polyphonic modulation section * 2500 note capability, and 6 memory banks. * Voice defeat system * Built-in micro-cassette deck for both se * Two assignable & programmable control quence and program storage. voltage pedals which can act on each man * Extensive editing & overdubbing facilities. ual independently * Exact timing can be programmed, and an * Three-band programmable equalization external clock can be used. * Program increment footswitch * Ability to change programs automatically in * Programmable volume control and a master the sequence. volume control * Transpose facilities for instant pitch * Octave transposition switches changes. * Upper & lower manual balance control * A-440 reference tone The Prophet-10 comes complete with a high quality flight case, two voltage pedals and two foot- switches. It’s now available; see your local dealer. Play the Prophet-10 today-It’s your ULTIMATE KEYBOARD.
For more information write to: SEQUENTIAL CIRCUITS, INC. 3051 North First Street Dept. K San Jose, California 95134 --- STAFF --- CONTENTS PUBLISHER John S. Simonton, Jr. ISSN: 0163-4534
EDITOR Craig Anderton Volume 7, Number 1 MANAGING EDITOR July/August 1981 Linda Kay Brumfield FEATURES ART DIRECTOR/ PRODUCTION MGR. Cynthia Rueb Build a $5 Analog Programmer...... 9 by Kirk Austin CIRCULATION Ramona French Peggy Walker Tube Tip...... 12 by Gerald Michaud BOOKKEEPING Helen Chalos Sample and Hold Composition Technique...... 13 PRINT PRODUCTION by Geoffrey Collier
SEMCO Color Press Applied Synthesis: Marketing your Records.... 21 POLYPHONY (ISSN 0163-4534) is published by Bill Rhodes bimonthly at 1020 W. Wilshire Blvd., Oklahoma City, OK 73116, by Polyphony Fender Amp Mod...... 22 Publishing Co. Entire contents copyright (c) 1981 by Polyphony Publishing Co. All by Lee Powell rights reserved. No portion of this publication may be reproduced in any Taking Control of Your MXR Phase 100...... 25 manner without written permission from by Matt Richards the publisher. No patent liability is assumed with respect to the use of the information contained herein. Second More GR-500 Comments and Mods...... ’...... 28 Class postage is paid at Oklahoma City, by Robert D. Loney OK 73125. ADVERTISING rate card and deadline schedule is available upon request. Modular Synthesizer Effects...... 30 Contact Linda Brumfield at (405) by Jim Aikin 842-5480. DEALERS & DISTRIBUTORS bulk prices are available upon request. Contact Linda Brumfield at (405) 842-5480. COLUMNS & REGULARS SUBSCRIPTION rates: American 1 year 12.00 2 years 22.00 Editor's Note...... Foreign 1 year 14.00 2 years 26.00 We now accept MasterCharge 1and Visa Letters...... payment for subscriptions, back issues, and PolyMart items. Foreign payments must be by charge card, money order, or Reviews...... certified check in US funds drawn on a US bank. Current Events...... 1 BACK ISSUES are available at $2.00 each ppd. Send SASE and request pur 'Back Issue List' for a complete index of Practical Circuitry...... 1 issues and their features, or see the back issue ad in this issue. Patch...... 2 CHANGE OF ADDRESS notifications must include your former address and zip code, and any numbers from the mailing Equipment Exchange...... 3 label, as well as your new address. When you move, be sure to notify your post office that you DO want second Advertiser's Index...... 2 class and controlled circulation ublications forwarded. This will save ost or returned issues. Polyphony is On the Cover: photo by Vesta Copestakes not responsible for replacement of lost or returned issues when we have not been supplied with change of address NATIONAL information. ASSOCIATION OF MUSIC MERCHANTS c r PTO POSTMASTER, send address changes to: LU POLYPHONY CD PO Box 20305 Oklahoma City, OK 73156 Ph. (405) 842-5480 ^NAM\A POUPHONU- — July / August 1981 If you've made a record yourself and are trying great for some people, but what if you can't afford to figure out how to market it, then read on...we've an ad? What to do... got some important news for you. Well, we've created an alternate means of mak I've been hearing a lot of excellent self- ing music, and proved that we can make music that's produced albums these days; in fact, the quality of as valid as anything coming out of the major labels. these recordings is starting to not just equal, but Next, we have to come up with an alternate means of to surpass the quality of product put out by the distributing. I don't have the answer, but I have a major labels. Interestingly, I recently had a con proposal. versation with the leader of a Major Rock Group The proposal is simple: that Polymart put out (hate to drop names, you know), and she was noting a sampler tape or LP, containing a cut or a few that the best drum sounds they were getting were not minutes of music from various self-produced albums. on the 24 track whiz-bang computerized board, but on This way, listeners can buy the sampler for a rela the lead guitarist's Portastudio. Why? They had tively low price, and decide what records they would time to experiment, to get the sound just right, and like to hear more of. all their Portastudio sessions took place under Now, there are a few details to the proposal, relaxed circumstances - a distinct contrast from the namely: often nervous atmosphere that prevails in a record • Polymart would NOT handle the individual ing studio, where you have to keep one eye on the records, only the sampler. Sources and prices for tuning and the other eye on the budget. all music in the sampler would be printed on the When it comes to independent artists, take album cover, or enclosed with the cassette. someone like Steve Tibbetts. His album was turned • All copyrights would be held by the artist. down by virtually every major label, so he marketed We're not interested in publishing songs; we're it himself. He's sold about 5000 copies of his 2nd interested in helping you get your music across. album, "Yr" (which is excellent by any standards), You would give us the right to use the excerpt of and the sales show no signs of letting up. your choice (not to exceed, say, 4 minutes) on the Then there's the fellow who calls me up sampler in return for the promotional advantage it periodically and plays me selections from his album would give you. in progress over the phone. It's all synthesizer, • Artists on the sampler would agree to re all fresh, and again, up to a very high standard of ceive no royalties for the use of their excerpt on quality. the sampler. The object of the sampler is to get as These independent musicians would appear to much music as possible out to the public for the have everything going for them: good studios, a minimum possible price; paying royalties would force good product, excellent music, and a degree of in an increase in the price of the sampler that might novation that you're just not going to find on the prevent people from buying it. Realize, though, radio. But they are lacking one thing: Distribu that Polymart would have to make some money off the tion. sampler, both in order to cover expenses and, if What brought this home to be was an album by possible, take out ads for the sampler in other Bill Rhodes, who also writes for Polyphony (see the magazines. article on marketing your own record in this issue). Interested? I thought you would be. Here's I had never heard of Bill Rhodes, but he had heard what to do. of me, so he sent me the album. The music was good, Send a copy of your LP or EP to SAMPLER, Poly but that's not the point...the point is that his mart, PO Box 20305, Oklahoma City, OK 73156, and work would appeal to lots of people, but since not indicate which selection you would like to have everybody is as visible as I am, most people will included on the sampler. We will then send you a probably never hear about it. form to sign giving us the right to use your I've played Steve Tibbetts' album for lots of material on the sampler, and also tell you when we people, and virtually everybody loves it. But, they expect to release the sampler. At the moment, I would never have known about the album had I not have no idea how many records we'll get; we may put played it for them first. out a cassette (which will probably cost less), or The problem is obvious: Who's going to buy an who knows, maybe there will be so much good stuff album from someone they've never heard of who lives we'll have to release a double-album! In any event, halfway across the country? We've already attacked we will not be able to return records. And, al the problem from one direction, by hiring a reviewer though we'll try to include as much material as who searches out as many independent releases as possible on the sampler, we can't guarantee we'll possible. And of course, you can always run an ad use your music...but we'll do our best. in Polyphony to promote your work, giving a brief You readers are the wave of the future in description that will hopefully pique people's in music. We want to help, in whatever way we can; the terest enough to induce them to send off some of sampler is a first step. their hard-earned cash for your record. That's Now it'-s your turn to participate.
4 POUPHCNU ■July / August 1981 Fernando - AMS stands for "Audio Modification System", and the AMS-100 is a modular system designed to process guitars, key LETTERS boards, tape tracks, or whatever. VANISHING BOOKS The AMS-100 was intended to be an Where would we all be without experimental system, and therefore our data books? The National can never be "finished" since it Semiconductor Linear Data Book is is always possible to design new the "bible" to analog speaking modules using new technology. I peoples everywhere. Why then can completed a basic AMS-100 system I not find a new one? A few years shortly before DEVICE folded; the ago you could buy one right off only modules not presented in that magazine were a random control Whether notching out the feed-back howls the shelf at the worst of elec in an unruly venue or sweetening the mix, tronics stores. Now even at Radio voltage generator and dual LFO/- sample-and-hold module. I had this four stage PAIA Parametric designed Shack they only shake their heads by Craig Anderton is the most powerful planned on presenting these in and look at you funny. What and versatile tone control available. Each gives? Polyphony, however, they are both of the 4 independent section features in Marc Briand obsolete designs by now and can be finitely variable control of frequency, Wichita, KS done more cost-effectively. After resonance and boost/cut and the handy I've re-designed them to reflect patch bay allows sections to be used Marc - What gives is that the current state of the art, they separately or together in any combina paper is expensive and getting will be presented in Polyphony as tion. With PAIA’s famous step-by-step in more so, printing is expensive, costruction projects. With those structions saving money is quick, easy and shipping books of that size is two modules and the modules al and FUN. also expensive. Add to that the ready presented in DEVICE (back Order TODAY and save even more by us fact that the electronics indus issues will be available from ing the free shipping coupon below. try, once considered recession Polymart; see center spread), you proof, is starting to lay off some can put together a pretty sophis HEWl Elect ronics^ Inc! people, close down some facili ticated sound modifications sys Dept, n y , 1020 W Wilshire B> Oklahoma City. OK 73116 (4051843-9626 ties, and so on. In other words, tem. Eventually, I'd like to put i I Send the 6760 Parametric Equalizer Kit. money is tight and these companies out a publication containing all $79.95 plus shipping for 3lbs. enclosed. I I Send Free Cat. have more on their minds than previous AMS-100 modules plus some keeping hobbyists up to date on newer ones as they come out. But name__ the parts they make. Of course, this won't happen for a while; I'm address, if you regularly buy $40,000 worth really swamped right now, and am city____ S22& ! of semiconductors, I'm sure you'll mostly concerned with building up visa___me__ card no______j have no trouble getting all the Polyphony. — Craig books you need. don't have enough time! With PC PATTERNS? We've got plans at Polyphony regards to articles from readers, for doing some data-oriented pub I have just become a sub we take what we can get and most lications on parts, since no one scriber to Polyphony (referred articles do not include PC board else seems to be doing it. For from DEVICE). I like this maga artwork (you're not the only one example, Thomas Henry and I have zine, however, there are no cir who finds the process difficult). collaborated on a booklet; and, we cuit board patterns printed with Also, PC artwork takes up a fair hope to put out a series covering your articles. Although I can amount of space in the magazine, the most popular electronic music build and use almost any project, but only benefits those readers parts. Of course, all of these I lack the expertise to design a who actually build the project. grandiose plans are subject to circuit board from just a schema When possible, we're going to time and money limitations, but if tic. Is there any hope that the try to offer PC boards either the first booklet goes over well, magazine will come to the aid of through PAIA or from the readers there will surely be more. readers like me in the future? I themselves. In the case of the In the meantime, refine your think you would appeal to a much latter, there is the potential for badgering techniques, and see broader audience (very important creating problems, because there about scoring older manuals from to a magazine looking for solven is no way we at Polyphony can companies when they get updated cy) by making this one change. monitor the quality control and versions. Good luck - as one who I also have a question about business practices of those offer has a hard time getting data your mini-amp project from EPFM. ing boards. We have one neat books, I certainly sympathize with Is there any way to incorporate an envelope generator project in the your plight. — Craig effects look into this design? works where the reader has sent us AMS-100 INFO This would help my teaching tre a professional, well laid out mendously by allowing my students board; he will be offering it to I am very interested in the to learn to use effects. readers. Let's hope we get more AMS-100 project you were running of these in the future. Edgar A. Stanton in DEVICE. Can I get photocopies With respect to an effects Louisville, KY of past articles? Did you finish loop, the place to add effects it? Please tell me more. with a mini-amp is between the Edgar - It takes me more time I also know that DEVICE had instrument and the input of the to generate PC board artwork than lots of mods to various pieces of amp. There is no preamp/power amp it does to develop and write an equipment. How can I get these? combination in an amp chip, there article; to build my prototypes, I Thank you very much for your fore, it is not possible to break use Vectorboard and a wire pencil. attention. that connection and insert a loop. This is why my projects don't Fernando Tepedino — Craig Sao Paulo, Brasil include circuit boards; I just PQUPHONU July / August 1981 5 OUR NEW MANUAL MIXER ENDS MANDAT
BUSSINJ m
poiarHOwy July/August 1981 Now nobody but you determines the Like the rest of the System 20, there’s nothing routes your signals travel. common about the 4 x 4 EX20 Microphone The Tascam System 20 isn’t your common Expander either. Four transformer-isolated inputs everyday mixer. with twelve patch points. We pulled all the switches (their logic is fixed Once you plug into the economy of our and limited) and put in patch points all along manual mixer, you can save even more the signal path. You make the connections, so practically anything you want is possible. When the job at hand changes from basics to overdubs to remix, you just change the way the System 20 works. All this flexibility brings incredible qual ity, too. Since you do your own routing, you can take shortcuts. Bypassing circuits you don’t need, getting really by hooking up with Tascam’s two new econom clean signals. ical compact recorder/reproducers. Both give The System 20 also ends your nightmares you 15 ips on 7" reels for 22-1/2 minutes of about needing an absolute fortune for a console quality recording time. with this kind of flexibility and quality. Now you You save in the long run, too. Because the can make the music you dream about at a price System 20’s modular design adds yet another you can afford. dimension of flexibility. It grows right along with The System 20 centers around the MM20 Mas you. So when you’re ready for 8-track, you just ter Module. It’s nothing less than professional. add another Master Module instead of an ex Four line inputs and two XLR transformer- pensive new mixer. isolated microphone inputs. Six output busses Visit your Tascam dealer for a demonstration. ready to change with the job. If you need three Then you’ll see exactly how the System 20 or even four effects busses you can just patch opens up new avenues of creativity. them in. Next, for truly flexible sound shaping, there’s the four-channel PE20 Parametric Equalizer. Low frequency range is continuously variable with sweep-type setting from 60 Hz to 1.5 kHz. Mid-range sweep control from 1.5 kHz to 8 kHz. And the high frequency is fixed at 10 kHz. Boost and cut for all three is ±12 dB. Then there’s the MU20 Meter Unit. Ready to 22-4. 4-track multichannel recorder. 22-2. 2-track mastering recorder. patch anywhere you need it. Like buss outputs or tape playback. And with its four VU-type averag ing meters and peak LED’s, you have the best of TASCAM seres'6 both metering worlds. TEAC Production Products
©1981 TEAC Corporation of America, 7733 Telegraph Road, Montebello, CA 90640
POUPHONU July / August 1981 7 M O O U L t t U D t
by Robert Carlberg
Laurie Anderson 0 Superman/Walk produced works, combining the key sey Solo: 0D0 0P8 FX (Bent 3). the Dog (single; One Ten 005). board dominance of Genesis with The Year of the Ear recordings are It is the arrival of records like the wide-ranging dynamics and brassy big band jazz (7 horns and this which makes this job so much time-changes of Egg or Hatfield. 4 percussionists) occasionally fun. Wacky and thoroughly de If these are the excesses against aided by Hersey's electric guitar lightful songs about mom, Dolly which New Wave rallies, too bad. and/or Avatar guitar synthesizer. Parton, and 30 ft. high dogs using David Moss, one of the Ear and vocoded vocals, small wind ensem George Crumb Makrokosmos Vol. I also featured on Michael Gilbert's ble, synthesizer and tape loops. (Nonesuch 71293); Makrokosmos The Call, brings a whole roomful This fruit of the trees planted in Vol. II (Columbia Odyssey 34135). of percussion with him and nudges the electronic decade deserves to A long experimental piano piece, Hersey into some pretty wild gui be heard by every music lover with made tolerable - even pleasant - tar improvisations. Solo is gui a sense of humor. by a constant tension between non tar and guitar/Avatar solos over standard playing techniques (di sequencer-triggered Oberheim Crutchfield's Dark Day E x t e r rectly on the strings, etc.) and chords - a nice blend of composed minating Angel (Lust/Unlust 229). brief snippets of normal tonal themes with stately ad libs. Nothing dark about these upbeat piano playing. little ditties built around LFO Michael Waisvisz Crackle (Claxon sixteenth notes. Very simple but Other Music Prime Numbers (OMJ 77.1). Waisvisz coaxes squeaks effective. 14); Gamelan Son of Lion Gamelan and rumbles out of a small, self- P in the New World (Folkways built synthesizer that sounds like 2 ImpLOG Holland Tunnel Dive/On 31313). Two groups who explore it's about to blow up. What he I B'Way (e.p.; Lust/Unlust 231). the similarities between Steve lacks in polish he makes up for in Who would have thought a blender Reich's phase music and tradi innovation. could take three solos over disco tional Javanese Gamelan music. beat electronics? "On B'Way" Both write for self-built tuned Steven Feigenbaum 6 Tom Scott really is the old Drifter's tune, percussion instruments. Things are More Like They Are Now sort of - lyrics are recited into Than They Ever Were Before (Ran a resonating filter, a poor man's Beakers/John Foster/Steve Fisk dom Radar 007). Scott is reedman vocoder. Life Elsewhere (e.p.; Mr. Brown with the Muffins, a fine neo- I 667). Gentle send-ups of the Canterbury/Henry Cow-ish group jody Harris/Robert Quine Escape charming naivete of the '60s Love from Maryland. Feigenbaum is an (Lust/Unlust 236) Formless guitar Generation. In particular, Fisk's all-around guitarist and the improvisations over a rhythm box. "Woodstock" should be required founder of Wayside Music. Listener endurance tests. listening for any remaining long- Together, on a variety of instru hairs . ments and in a number of styles, they sound like a much bigger David Keane Lyra (Music Gallery ensemble of consummate musicians, i Editions 29). Process music for in the best tradition of recent piano, double bass, voice and British jazz. oscillator (one track each). I Heavy on "exploring the tonali Keith Slane Star Captain (Aural ties" - some of which are fasci Explorer 5011); Quantum Jump/Home nating. (single; Akustic 12271). Science fiction and electronic music are Baird Hersey & The Year of the Ear inexorably mixed in some people's Lookin' For That Groove (Arista minds. Although he writes some Jeff and Jane Hudson World Trade 3004); Baird Hersey & The Year of very pleasant synthesizer rock (e.p.; Lust/Unlust 243). Kitschy the Ear Have you Heard? (Arista tunes, Slane feels compelled to non-vocals over rhythm box and 3016); Baird Hersey & David Moss doll them up with R2D2 sounds, continued on page...... 12 minimal synthesizing. They sound Coessential (Bent 2); Baird Her 8 bored. "OUPHONy July I August 1981
Joy Division Closer (Fact 25). Take a real drummer who sounds like a drumbox, add monotone vo cals and drone keyboards. Mix well and half-bake.
Happy the Man H appy the M a n (Arista 4120); Crafty Hands (Arista 4191). Complex, heavily .Huiia a
POUPHONy July / August 1981 9 (MMMT ‘ Tell Them You Saw It In Polyphony ’
New Recording Techniques/Sig- position/ performance at one time, nal Processor to be Unveiled at lists for $3295. AES. On October 31 at 7 PM, at the Waldorf-Astoria in New York New Music from CRI. Com City, Craig Anderton will present posers Recordings, Inc. (170 West a paper on Synchro-Sonic recording 74 St., New York, NY 10023) has techniques at the 70th Audio Engi released three new albums: Music neering Society Convention . This of Warren Benson (CRI SD 433),. process optionally ties all signal Percussion Mu?ic by Read and Mac processors, instruments, and elec Gregor (CRI SD 444), and New Music tronic events (vibrato, LFO From Sweden (Louisville LS 773). sweeps, sample-and-hold, etc.) into one rhythmic framework, traceable to one master clock. Many recorded examples, mostly Electro-Harmonix Digital De drawn from Craig's upcoming solo lay Makes Debut. E-H's new device album, will demonstrate the con gives up to two seconds of delay; siderable potential of Synchro- you may also record up to two Sonic music and recording tech seconds of music in digital memory niques . and play it back continuously Also, Harald Bode, the sub while you play along with it. ject of an upcoming interview in Claimed specs include delay time, Polyphony by Jay Lee, will be 8 ms to 2 s; high-end frequency presenting a paper entitled "Psy response, 12 KHz ^3 dB up to 1/2 cho-Acoustical Aspects and Musical second, 3.5 KHz + 3 dB from 1/2 Applications of an Infinite second up to 2 sec; S/N ratio 85 Phaser". The presentation will dB; and distortion, less than 5%. include an historical perspective The unit also includes chorus and on this type of signal processor, vibrato capabilities. as well as recorded compositions that showcase the process of in finite phasing.
16 Track Studio Console. TEAC (7733 Telegraph Road, Monte bello, CA 90640) has announced the M-16, a mixer with 16 or 24 input positions. Features include 8 main program mixing busses with submaster faders, 8 main board outputs, 2 independent stereo mix ing busses, 4 aux mixing busses, 16 meters, 4 band/8 knob bypass- able parametric equalizers, and 3 Also from E-H is the Graphic filters (two high-pass, one low- Fuzz, which includes a built-in pass). The M-16 lists for graphic equalizer and preserves $12,900. the dynamics of your playing. Craig will be reviewing this de vice in an upcoming issue of Mod ern Recording & Music magazine.
New from Roland. The MC-4, an updated version of the MC-8, Marshall from Unicord. Uni allows programming of up to four cord (89 Frost St,, Westbury, NY pairs of voices from either a 11590) has announced the introduc synthesizer keyboard and/or the tion of the Jim Marshall Signature MC-4's calculator style keyboard. Series Amplifiers. Models include Performances can include pro the basic Marshall 50 and 100 Watt grammed pitch, rhythm, programmed lead amplifiers, available in both Shhhhhh. dbx is introducing dynamics, programmed tempo, and standard format and with Master a two-chip set designed to replace more. Tape sync is provided for Volume, as well as the new model the discrete components in a dbx building multi-track compositions; 2000 200 Watt lead and 2001 300 noise reduction system. For fur tape interface allows for storage Watt bass units. The latter mod ther technical and licensing in of composition/performance data. els utilize a two channel design formation, contact dbx at 71 Cha The MC-4 with 48k of memory, which with channel switching facilities, pel St., Newton, MA 02195. allows up to 11,500 notes of com and FX loop for all channels.
10 PO^PHOW y------;------July/August 1981 “ Please Plug Polyphony ”
PAIA Manuals Sound Off. PAIA demonstrations of PAIA's Organtua, Synthesis Information Service (1020 W. Wilshire Blvd., Oklahoma Proteus I and the Drum were pro in Great Britain. Electronic Com City, OK 73116) now includes duced by Craig Anderton. As an puter Synthesizer Sound (The Sound demonstration cassettes with the added bonus, the Proteus I demo House, PO Box 37b, East Molesey, instruction manuals for their most includes five new instrumental Surrey KT8 9JB, UK) is a center popular musical instruments. Of compositions from Craig commis for the research, development, and particular interest to Polyphony sioned specifically for this tape promotion of electronic synthesi readers will be the fact that the by PAIA Electronics.______zer sound. Services include: in formation service and library, list of recordings and publica tions, distribution center, more.
Music for Health. Those who are interested in music as a heal ing force should be aware of Hal- pern Sounds (620 Taylor Way #14, Belmont, CA 94002). Steven Hal- pern has recorded numerous albums designed to :,tune" the human body and promote mental/physical/psy- Korg LP-10 Piano. The LP-10 board, chorus effect, key trans chic well-being. A book explain offers mixable acoustic piano, pose switch, variable decay char ing Halpern's philosophy, "Tuning electric piano, and clav timbres acteristics, and a built-in 6 band the Human Instrument", is also in a portable, 22 lb. package. graphic equalizer. Korg, division available. Write to the address Features include 5 octave key of Unicord, 89 Frost St., West- above for brochure. bury, NY 11590. SOMEDAY U’LL NEED A COMPUTE LUCKILY, YOU ALREADY KNOW OST IMPORTANT THING TO LOOK
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POUPHONLi July / August 1981 11 re-view TUBE —TIP continued from page...... 8 laser pistol zaps, and even Star Wars cantina by Gerard Michaud sequence. The single presents two of the better tunes, sans silliness.
We can substitute 6CA7 tubes Ilham Mimaroglu Tract (Folkways 33441). Subtitled in amps originally fitted for "Agitprop Music" for "agitation-propaganda", T r a c t 6L6s; however, the price paid is was composed in response to political upheaval in some crossover distortion. To Mimaroglu's native Turkey. Radio fragments, pieces cure this, simply feed a sine wave of poems and female voice are collaged over piano generator into the input, and and Columbia-Princeton synthesizer. There are many adjust the bias control (like the outside references. one on Fender amps found just beside the choke and power trans Craig Kupka (and others) Clouds (Folkways 6195). former) until the crossover dis "Non-stress inducing" meditation music for relaxa- tortion disappears. The advantage tion/blocking out unpleasant distractions/concen- of using 6CA7s is a somewhat trating on inner feelings. Very slow modal improvs crisper, more defined treble, as for vibes, Rhodes, celeste, guitar and synthesizer - well as bass that's a little bit musical Valium. Yawn. tighter. You can also substitute 6550s with no bias modifications, Gianni Safred Futuribile (Folkways 6253). I'd but you must then add a fan for never heard of jazz pianist Safred before - now I cooling. 6550s last longer than know why. Schlocky swept-filter disco-beat synthe 6L6s due to their special con sizer with titles like "Disco Satellite", "Robot struction, and do not get micro- Party", "Jazz Computer", etc. Eminently forget phonic. c table.
Phillip Perkins Tool's Paint/Reading the Mail (single; Fun 1001). Several layers of hollow elec tronic bonging (created by slowing down the click of a whistle) b/w the cacophony of CB radio over a slow organ processional. Personal visions you won't hear on the radio.
Barton McLean (and others) Electronic Music from BY PROFESSIONAL DEMAND the Outside In Folkways 6050). Narrated instruc DDC OFFERS FREE ADVICE, PERSONAL SERVICE tional 2-LP set on tape-music technique. Just like AND ONE-DAY SHIPPING OF THE FINEST MUSIC it says in the album notes: "...a foreknowledge of AND SOUND EQUIPMENT AVAILABLE ANYWHERE: electronic music is not at all necessary. On the other hand, anyone who has anything to do with C f O L L i n Lraynor electronic music can, perhaps, benefit from these KORG Pol*YP^si°r> insights..." K€LS€Y^ ggg|IMiTlT1 Randall McClellan Genesis/Interruptions (Opus One 24). McClellan is the direction of the E.M. studio TEAC TUNER [ m X h ] 3ME at Hampshire College, Amherst. He could take a lesson from his student Michael Gilbert in coming back to earth; both pieces are typical academic oscillator exercises. They are ten years old, though. REMO t o p c o m Lew Corelis/Jack Schrage: Music Werks Songs You've ___ © YAM AH A Never Heard Before (River Music Werks). Electronic C WIUllMiA R OIWTlH*illl ^rausvJil__(S L JjL keyboards (mostly Poly- and minimoog) create sound HnBTllSTB' 1 I textures which only rarely break out into "songs". Unfortunately, for me most of it is not thick enough pRopbet & RO/ A to prosper as textures, and too abstract to function as songs - an uncomfortable no-man's land. CSC! Emerald Web Dragon Wings and Wizard Tales (Star- gate 4230). Emerald Web is flutists/synthesists Bob intersound J0U& Stohl and Kat Epple, both steeped in mysticism and PLEASE CALL OR WRITE FOR PRICES & ORDERING evidently much music - everything from TONTO to INFORMATION - YOU'LL BE GLAD YOU DID! Stravinsky to King Crimson. Delicate flute solos,
w m ^ h q i c k s t e i n distributing c o m pa n y | g g § mournful pitch-bends and occasionally Ms. Epple's ' 1120 QUINCY PPY—SCRANTON, PA 18510 j breathy voice over string synthesizer chords make up J J PHONE ORDERS WELCOME 17171 344 7469 ; the most of it. The record is almost too broad to have a personality. C
12 POUPHOM ------July / August 1981 by Geoffrey Collier
When first exposed to the input results in a series of ap confused by a constantly changing sample and hold (S/H) module in a parently random output voltages. clock rate. college synthesizer course, X was However, this randomness soon be We can begin by sampling a totally thrilled - but also total comes boring; so, I started ex very low frequency sawtooth, which ly confused. Subsequent investi perimenting with sampling repeti yields a long, ascending scale gation cleared up my confusion and tious (periodic) waveforms. The like pattern that periodically exposed me to the many sounds of results obtained by sampling a jumps to the beginning and starts which an S/H is capable. In this sawtooth wave were most interes again (see figure 1). Because of article, we'll cover some of the ting, so we'll discuss this sub the virtual impossibility of get many talents of this versatile ject in depth. In order to best ting the clock rate to be an exact module. hear the results of these experi divisor of the period of the wave, the odds are very small of gen erating a pattern that will repeat itself exactly. Because there is Clocktime 20 of the period of one wave a slight amount of overlap at the crest of each wave, the Initial £lock Period (my term for the first sample o’f each wave and therefore the lowest note in each scale) will constantly shift ICP downward towards the onset of the ICP wave, causing each scale to be ICP + 3 + lower than the preceding one. DESCENDING ICP’s Finally, what would have been the ICP of the wave misses the begin CLO CK TIM E < IT the period ning of that wave altogether, lands on the tail end of the pre ceding wave, and gives that wave Basics of Sample and Hold. ments, I sent the S/H output to a an extra note. As a result, every Each of the S/H's two inputs and VCO. few measures (reverting to musical one output introduces a variable terminology), there will be a bar worth exploring. The output, Experiaenting with the Con with an extra beat, creating such which takes the form of a varying trol Voltage Input. The sampling interesting polyrhythms as 7 + 7 + control voltage, may be fed to process is somewhat reminiscent of 7+8. We can control how often voltage controlled modules "as is" the story about the blind men and the bar with the extra beat occurs or processed by control voltage the elephant - we have to get lots by controlling the rate of descent processors. Traditionally, one of of shots of a single wave, or of the ICPs (a function of the the inputs samples the voltage of we'll end up with a rather contor wave frequency); the slower the a waveform (Control Voltage In) at ted image of what the wave must descent, the less often the longer a rate specified by the clock rate look like. We can increase the bar occurs. This makes it possi present at the other input (Exter number of shots by coaxing our ble for us to consciously generate nal Clock In, Sample In, or some "photographer" into working faster a number of different polyrhythms. times Strobe In). For now, let's (increasing the clock rate), or by Once again, however, because the investigate some of the waveforms slowing down the wave in order to mathematical relationship between suitable for sampling by the S/H. keep pace with our reluctant pho the clock rate and the wave period The easiest way to understand tographer (decreasing the frequen is not exact, a pattern will not an S/H is to think of it as taking cy of the waveform being sampled). maintain itself indefinitely. We periodic snapshots of the waveform Since either option will yield the can overcome this problem by being sampled, with each still |same result, we can perform our taping a segment of the pattern shot corresponding to a discrete experiment by playing with only and then getting it to repeat voltage level. This voltage level one of the two variables. I chose itself with splicing techniques becomes the module's output. to work with the frequency of the or through the use of a tape loop. On my ARP 2600, as on many wave, rather than changing the As we increase the frequency synthesizers, the sampling source clock speed, because this enabled of the wave, the descent of the input is normalled to the white me to concentrate on the different ICPs slows, and they come to a noise generator. Sampling this patterns available without being standstill, causing the scale to
POUPHONy July / August 1981 13 curs through smaller and smaller increments of the tuning control. This is because the tuning control Clocktime m of the period increases the oscillator's fre quency exponentially, but the clock looks at the wave from a linear point of view - it sees an increase of frequency from 100 to 200 Hz as being the same as an increase from 1000 to 1100 Hz.
Exploring the External Clock Input. By using the square wave of a VCO in its low frequency range we can now voltage control repeat itself. The ICPs then starts to ascend, individual the sampling rate. Note that begin to ascend as we can see on pitches can be heard and we have changing the pulse width of the figure 2. During the ascent, the an ascending scale (see figure 5). sampling wave will make no dif odd bar now contains not one ex We have now come full circle, and ference to the S/H because the S/H tra, but one fewer, note. As the we are back where we started - responds only to the leading edge frequency increases the short bar except that the samples are occur of the wave (other S/H designs may occurs more and more often, until ring on successive waves rather not follow this convention, inci the two bars alternate with each than different portions of a sin dentally). We can experiment with other (say a 7 and a 6). If we gle wave (which makes no practical a variety of control voltages (CV) push the frequency a little difference). This entire cycle to the clock wave. We can, for higher, the 6 will become a more common rhythm, and at the same time the ICPs will start to des 3 1 cend. We are now back where we CLOCKTIM E
Clocktime 5<7 of the period
—
DESCENDING LINE DESCENDING LINE
CLOCKTIME APPROACHES PERIOD
C lo cktim e w of the period
SLOWER DESCENDING LINE
14 POUPHONU July I August 1981 CLOCKTIME > PERIOD C locktim e 20 of the period
1 + 1 + 1 + ASCENDING SCALE
Or, we can use an ADSR envelope of which module receives the S/H voltage’ transition. However, the generator triggered by the gate or output. Unusual patches can be only true solution would be to use trigger voltage. Every time a new created by sending this output to two different S/H uni*ts that are note is hit, the sampling rate the VCA and some of the more eso both being triggered by the same will speed up and slow down in teric functions available on your clock, which would randomize the complex patterns determined by the system, such as voltage controlled audio outputs of the two modules ADSR control settings. Another resonance (VCQ) or voltage con yet preserve the same rhythmic alternative is to create a feed trolled reverb. However, I will relationship. back loop by sending the S/H.out focus on the more common and per Many other possibilities re put back to an LF0 feeding the haps more useful choice of the VCO main to be investigated, such as clock. This will cause the high and VCF. One of the most basic mixing waves before and after CVs to rush by quickly and the usages is to send the S/H CV to sampling them, or mixing the S/H slow ones to take their -time the filter, thereby creating a output with other CVs before send (again, this is an invertable rhythm against which you can play ing it out. I hope, however, that process by adding an inverter). fixed melodies or improvise. High I have pointed the way towards a There are other interesting resonance filter settings provide few avenues for further experimen clock possibilities. If we use the most dramatic emphasis of the tation. c the controller trigger voltage, we rhythm, if also the most hack can, for instance, get a different neyed. The contrast between beats timbre with every note we play. can be heightened if you have VCQ We can also use any external and send the CV to this input as PGS- Your authorized hobby source such as an instrument or well as to the cutoff point. TL062CP... 1.55 distributor for SOLID STATE tape. The clock input of many S/H More dramatic rhythms come TL064CN... 2.45 MICRO-TECHNOLOGY. High modules will respond to any from using the VCOs, although this T1071CP...... 80 Quality, Inexpensive I.C’s sharply rising amplitude change; eliminates the possibility of TL072CP... .1.35 for Audio and Electronic Music TL074cn ... .2.25 when there are rapid amplitude creating controllable melodies. I applications. changes, the clock gets confused find that the best effects come NE555P...... 39 and a strange warbling results. from tuning the oscillators to an NE570n... .3.75 VCC’S VCF’S NE571n... It would be interesting to then interval and maintaining this in .2.85 SSM2030...... 7.50 SSM2040...... 7.50 feed the tape through a filter terval by putting the CV into the NE572N... 5.30 SSM2033...... 10.00 SSM2044...... 5.75 which is being controlled by the lV/octave inputs of the oscilla UA741CP.. ...29 VGA’s ACSR’s RC1556nb .1.48 S/H output, causing timbral tors. I like the sound of a few SSNI2000...... 7.50 SSM2050...... 7.50 MC1556G- .1.48 changes on the program material to fifths or fourths of the same SSM2010...... 7.50 SSNI2055...... 6.50 CA3080E. .1.00 SSM2020...... 7.50 SSM2056...... 5.75 be a function of amplitude waveform piled on top of each CA3280G .1.98 changes. other, all moving in parallel XR4136CP .1.10 A good tape technique is to motion. XR4739CP .1.30 Analog record the clock, allowing us to One problem that I encoun MK50240N .5.47 Delay I.C’s overdub a number of rhythmic tered is that if the CV is going SN76477n...2.48 SAD-1024A....21.00 layers in sync with each other to several different modules, the * T099 Can SAD-4096...... 36.00 (editor's note: see Tom Henry's effects achieved will always work We also carry resistors, jacks, plugs, and More. column in this issue for addi in parallel because a given vol Write or call to be placed od our mailing list tional information on the tage change will cause a predicta and receive our free flyer! tape/sync track interface). The ble change in each module - for clock can be heard as an audible example, a high note will always SATISFACTION GUARANTEED! TERMS: No minimum on check or money orders. If less than click on the tape, although it is occur at the same time as an open $10 add .75 processing charge. $10 Minimum on charge orders (MasterCard and VISA). Please supply card no., expiration at twice the clocking frequency filter. We can improve the situa date, and interbank no. (MasterCard) Sorry, we do not accept COD's. Indiana residents add 4% sales tax. because the S/H responds to the tion by processing the CV before SHIPPING & Handling: $1.00 plus 5% of purchase. leading edge of the wave only. it goes to the one of the modules. NOTE: Prices and availability subject to change without notice. Not responsible for typos. We reserve the right to substitute In addition to inverting it, we manufacturers. (Due to back orders, etc) Output Cons iderat ions.I'd can put it through a lag processor like to close this article with a (slew limiter) which will give the ELECTRONICS few comments on the final link in pleasant effect of rounding off 24 Hr Order M m ift Pleee P.0. BOX 735 the S/H chain, namely, the choice the sharp edges of each control 812 894-2839 TERRE HAUTE, IN 47808
P0UPH0NU ■July / August 1981 15 Last time we talked about how to find new transistor (see figure 5). In this configuration outputs on the SN76477. In this installment, let's the transistor acts like a throttle, and determines switch gears and talk a little about how to get more the current flow through pin 4, hence varying the sounds from the noise source. clock rate. SN76477 noise source background. The white Before getting too heavily entrenched in de noise source in this chip is not the back-biased tails, I suppose that I should say something about transistor you might be familiar with, but a binary why we want to change the clock rate. The best pseudo-random noise generator. I don't want to get answer I can give is "try it, you'll like it!". The too heavily into the theory of this (see Don Lancas sound is an incredible swooshing noise, and is very ter's TTL Cookbook, Howard W. Sams, 1974, pp 277-283 similar to phasing or flanging. The noise takes on for a good treatment), but all we really need to a new tonality, and sweeping the clock changes the know is that the noise source is basically a shift spectra in an eerie and dramatic manner. register, with various bits moving down the register White noise percussive voice. The circuit in at a rate determined by a master clock. This clock figure 5 is specially adapted for a percussive can be either internal or external to the chip. voice, with the noise amplitude being controlled by Let's consider an internal clock circuit first. the envelope generator and VCA. In addition, the Normally the resistor connected from pin 4 to ground envelope is tapped off of pin 8 and applied to the sets the clock rate, and that's that. However, we base of the transistor. The result is a voice which could just as easily replace the resistor with a sweeps as the envelope dies away.
16 POUPHONU ■July / August 1981 You will also note that the its sweep range; when you need which programs the chip to accept envelope is tapped via a 10 Meg lots of sweep, try the circuit in an external clock. resistor. The reason for such a figure 6. The rest of the circuit is large value is to avoid loading Here we avoid the internal the same as that described in the down the envelope generator capa noise clock completely, and use an last installment, with the noise citor. We could have buffered external clock instead. Actually, taken off of timing capacitor Cl. this voltage first using something the "external" clock is really We have to take out the noise this like an op amp, but the loading internal to the chip, being the way since the chip's normal out caused by the 10M resistor is VCO. This is a good way to save put, pin 13, is already committed negligible, and is certainly cost- parts, space, and wiring hassles. to the VCO. effective in this situation. However, if you were planning on Calibration. To adjust trim Since the Beta (or DC current using the VCO for something else, mer R6, turn down RI and R3, and gain) of transistors varies from you could always clock the noise advance R6 until the noise just one unit to another, it may be with virtually any other type of begins to be audible. This sets that 10M is too large to allow the square wave oscillator. the lowest noise frequency. particular transistor you pick to Let's analyze the circuit; Once the circuit is cali turn on sufficiently. Feel free consider the VCO first. R9 and a brated, start experimenting. You to experiment with other values; capacitor selected by SI (C2, C3, could apply an ADSR to Jl, or an any value from 1M to 10M is per or C4) set the basic VCO frequen envelope follower, LFO, sequencer, missible, but don't drop below 1M cy. A control voltage applied to etc. - you get the picture; we're or excessive collector current may J1 is summed through IC2 and ap talking about a staggering amount flow through pin 4 of the SN76477. plied to the control voltage input of sounds, and they're all ex Before leaving figure 5, you of the VCO, which sweeps the VCO tremely useful. If you thought should be aware that this would frequency. Since IC2 is an in white noise had to be a static, make a nice modification to the verting stage, an increasing volt one-dimensional effect, this cir Percussive Noise Voice (John Bla- age at J1 yields an increasing cuit will definitely turn your
offset trim _15 R6 100k +15
cet, POLYPHONY, Nov/Dec 19779, pp frequency. R3 offsets the VCO if head around. 12-13, corrections in the Jan/Feb desired, or can be used as a manu Next month, we'll tie to 1980 issue, p 5). al sweep control. Trimmer R6 sets gether what we've covered so far, Expanded noise sweep. Sweep the zero point of the VCO so that plus more, with a complete pro ing noise effects really appeal to 0V applied to Jl gives the minimum ject, the "Super Controller Mod me, and ever since discovering how VCO frequency. Diode D1 prevents ule". I think you're going to to do them, I have been constantly, any inadvertent negative voltages like this one! at work developing new ways to from creeping into the VCO. The Acknowledgement. My thanks employ this technique. One of the VCO's square wave output is taken go to Craig Anderton for turning limitations of the circuit in off of pin 13 and sent to the me on to the use of a transistor figure 5 is that the internal external noise clock input at pin to control the internal noise noise clock is slightly limited in 3. Pin 4 is tied to the +5V line. clock. ©1981 Thomas Henry C POLUPHONU July / August 1981 17 POLYMAR 7 •f , 7 / ? i The physical and psyc } - - . , . iiS;; ’ ,K. -Qt?‘:,j' Helmhotz’s Sensatio physiological acoustics Psychology Test, provides an in-i of Music instruments. M usic, Carl ll-Scashon* synthesizer, is a thor instruments (plus a chi like the Helmholtz wor
#SEIU S On The Sense # M P E Music, Physics
Synthesists must be wi books are a great way t and Modugno is a stanc tape technique, compos building, outfitting, and computer control of eli Home Recording For maximum results, inclu
#H M EM How to Make # B Y T E Byte Book of C
S Electronic cookbooks a theory, definitions, and i can easily replace stac reference. W alt Jung's required reading for sy applications. Lancaster octave generators, tot i electronic construction recording of the effect! #O A C B Op-Amp Cook I # A FC B Active Filter C #AU O A Audio Op-Am|
Often used reference n The Source is over 12 AUDIO type. Audio Cycloped to answer any question CYCLOPEDIA publication without pur Synthesizers devotes Paia, Oberheim. EML, experimenter. mm # mtcmk aw kmmamw lUt most <>.(■»■ t Mstf-AfiMcVi' f< ft ■!''/■>'> , i # S O U R C E The E #C Y C LO Audio 18 POUPHONU July / August 1981 POLYMART is provided to help Polyphony readers find the SCIENCE special supplies their projects require. The items we stock are a must for every active music experimenter’s lab or studio icoustical background to music is an important part of musical synthesis, bookshelf. Not all of PolyMart’s offerings are shown in each of Tone is, a century after its publication, still the standard text for sychology of Music by Carl Seashore, developer of the Seashore Music issue. Refer to back issues if you don’t see what you want. Your th analysis of musical style and performance characteristics of many suggestions for additional items are welcomed. ysics, and Engineering by Harry Olson, who worked on the first RCA h discussion of the physical properties and design of traditional musical TO ORDER: Tear out this half page order blank; note that there is ;r on electronic music). Music, Sound and Sensation by Winckel is much 'ith a bit less detail and more concentration on psycho-acoustics. a back issue list on the other side. We cannot invoice; payment must be enclosed with your order. To help defray shipping and i Of Tone $7.50 #PSYCH Psychology of Music $ 5 .0 0 packaging costs, there is a flat $.50 handling fee per order plus Engineering $6.00 #MSS Music, Sound and Sensation $ 3 .5 0 payment of postage costs. MasterCharge and Visa are welcome, but there is a $10.00 minimum on charge orders. Foreign orders must be paid by certified check or money order RECORDINGS in U.S. $ drawn on a U.S. bank (or by charge card). Phone orders are welcomed for charge card orders only. & 8 C O R D S Cords - Synergy $ 7.95 8 E R R 0 Electronic Realizations - Synergy $ 7.95 Name: ______* < #SEQU Sequencer - Synergy $ 7 .9 5 A ddress:______v a V #GAMES Games - Synergy $ 7 .9 5 #PICT Moving Pictures - Michael Gilbert $ 7 .9 5 City ______S ta te ______Z ip ______jL. #ELEM Elements - Mychael Danna $ 6 .9 5 Card #______#CAMT Craig Anderton Music Tape $ 5 .9 5 MasterCharge Bank # ______Expiration D ate------#MOEB Moebius - Moebius $ 7 .9 5 #ARPT Music For Airports - Brian Eno $ 7 .9 5 Signature ___------#OELTA Rainbow Delta - Pat Gleeson $7.95 Quantity Item Price TECHNIQUE ersed in a number of techniques and principles. "How to" and project oriented ck up these skills easily. How to Make Electronic Music by Drake, Herder I introductory text for music systhesis classes, with chapters on equipment, in projects, and more. M u ltitrack P rim er by Teac is a step-by-step guide to arating your home studio. The Byte book of Computer Music describes 'o-mechanical instruments, Fourier analysis, circuits and loads of software, u sicians is the original guide to outfitting and operating a budget studio for g mixer and audio processing circuits and a demo recording. :ctronic Music $3.95 #TEAC Multi-Track Primer $ 4 .9 5 puter Music $10.00 #HRFM Home Recording $ 9 .9 5 .# of items Sub Total ------Shipping Changes------Handling 50 U.S.:add 10°/oof Sublbtal ELECTRONICS on $5.°°m axim um 3 great way to stock your library with materials that are not only heavy on Foreign: 20°/o of Sublbtal Shipping cational material, but chock full of practical applications as well! These books or S'10.00rnaximum of manufacturers data sheets and applications notes all in an easy to use p-Amp and Don Lancaster’s Active Filter books are self-explanatory — esists! Audio Op-Amp is an edited version of OACB, containing only audio :M O S book is much more than a digital reference — phase lock loops, top SUBSCRIPTION switches, and other things you need! Electronic Projects discusses thnique for the novice and provides 19 projects with PC patterns and a demo U.S. S12/YR. SS2/2YRS. FOREIGN S1A/YR, S26/YR. >k $14.95 #CMCB CMOS Cookbook $ 1 0 .5 0 tbook $14.95 #EPFM Electronic Projects2nd edition $11.95 SUBSCRIPTION pplications $ 7 .9 5 Back Issues (from other side)____ REFERENCE Total Enclosed ■rials to answer the many questions encountered in everyday synthesis!?)... ages of patches in universal flow chart notation; the largest publication of its ias 1760 pages with 3650 entries and hundreds of drawings and schematics :out audio. Polyphony Binders hold up to 12 issues of any 8 V2" x 11 ” Return This Half Page ing holes; keeps issues like new for unending service. Electronic Music le first half of features and functions of commercial equipment (Moog, Arp, d RMI); the second section provides schematics and projects for the To: POLYMART P.O. Box 20305 rce $4.00 Oklahoma City, OK 73156 fdopedia $39.95 ^nthesizers $6.95 $4.95 V/SA .. POUPHONU July / August 1981 19 •MORE - FROM - POLYMART. USE ORDER BLANK ON PRECEDING PAGE ____ . BACK ISSUES The wide variety of practical applications and construction projects in past issues make a binder full of Polyphonys a frequently used reference to keep near your synthesizer, home studio, or workbench. Most issues are still available for $2.50 plus $.50 shipping/handling. Check the issues desired on this coupon and add the total to your PolyMart order (other side), or order by volume and issue number (0304, 0402, etc.) on the PolyMart form. #0101: 1975: SOLD OUT #0202: 2/76: SOLD OUT #0201: 1/76: SOU) OUT #0203: 3/76: SOLD OUT □ #0204: 4/76: music notation - timing, external inputs for Gnome, Programmable Drums, Equally Tempered D/A, low cost AR project, digitally encoding keyboards, patches, Volume 1 & 2 index. CD #0301: 7/77: frequency divider project, random tone generator project, normalizing synthesizer controls, eliminating patch cords, computer control of analog modules, Chord Egg modification, adding pitch bending, patches. P. #0302: 11/77: The Sensuous Envelope Follower, digital gates, LED wall art, build a bionic sax, data to music peripheral project, Apple II as a music controller, using the NE566 as a VCO, patches. i—| LJ #0303: 2/78: computer controled Gnome, using joysticks, build a bionic trumpet, ultra-VCO modifications, Without a logbook remix and overdubs often mean voltage control the Mu-Tron Bi-Phase, oral joystick, to re-familiarize yourself with the piece. Having patches. important information on your tape library in one place as opposed to take sheets scattered among a lot of different CD #0304: April/May 78: Minimoog modifi reels is convenient but more importantly, a well-kept cations, non-keyboard module use, phasing and flanging logbook becomes part of your records for tax, accounting and (theory and circuits), memory expansion for programmable planning purposes. drums, digitally addressed transposer project, polyphonic software (with software transient generators), patches, This 4/8 Track Studio Logbook represents an improvement over Volume 3 index. standard track sheets in that you can not only indicate □ #0401: July/Au^ust 78: analog delay lines (theory technical information such as timing and type of tape used; and projects), composing for electronic music, note to there is also a generous amount of space for recording frequency (and visa versa) conversions, build a trigger patches and making notes, as well as an expanded track sheet delay, software for computer composition, low coat VCO page that provides space for listing sequential changes in circuit, patches. various tape tracks and relating these to settings of the _ index counter. l— 1 #0402: Sept/Oct 78: electronic music notation, notes Order # SLB...... $4.95 on the recording of "Cords" by Carry Fast, sequencer software - part one, rhythmic control of analog sequencers, touch switch projects, modular vocoder techniques, PET as a music controller, patches. #0403: November/December 78: SOLD OUT □ #0404: January/March 79: add-ons for vocal F and V converter, shorthand patch notation, more on note to frequency conversion, graphic monitor project, George Russell, super VCA circuit, echo software, Vol. 4 index. #0501: May/June 79: SOLD OUT □ #0502: July/August 79: hex VCA/mixer project, electronic music schools and studios, modify the Oberheim Expander Module, profile of Ernest Garthwaite, budget microphones, digitiser projects and software, bar grapg XCs. #0503: September/October 79: SOLD OUT #0504: November/December 79: SOLD OUT j—i LJ #0505: January/February 80: Joseph Byrd, Mort Garson, Larry Fast on 'Games', composing for 'live plus tape', using the CA3280, recording vocals, ADSR circuits. □ . #0506? Harch/April 80: Computers in Music: real time audio processing hardware, Powell sequencer system. Max For those of you who have been asking for Craig Anderton's Mathews, advanced STG software, PortaStudio, phase Contemporary Keyboard reprints (June 1977 - February 1981) modulation, Volume 5 index. here it is. Article topics include tips, technique, theory, #0601: May/June 80: SOLD OUT maintenance and projects, such as, Design and Build: Keyboard Mixer, Keyboard Pre Amp, Multiple Identity Filter, [D #0602: July/August 80: Peter Gabriel, digital VCO Combo Organ, Tremolo, LED Control Voltage Meter, Expansion project, dream modules, optimum level settings, dynamic Oscillator, Noise Generator, and more. phrasing, patches. Order # A A ...... $6.95 ED #0603: Sept/Oct combined with Nov/Dec 80: alternate controllers, add voices to Caaio M-10, voltage controlled quadrature oscillator project, cordless patch bay, recording rules, patches. DEVICE AVAILABLE... Since DEVICE and POLYPHONY merged, one of our most requested #0604: January/February 81: Special Construction items has been DEVICE back-issues. And no wonder; during tion; Build: Audio Circuit Breaker, Pulse Width the year that this newsletter for guitarist/musician was Multiplier, Magnetic Harp, 50 Watt/Channel Stereo Power Amp, published it featured an extraordinary quantity of material aQuad Sequential Switch, DOD Mods, patches. of interest to anyone involved with music at any level. These twelve issues provide almost 200 pages of solid I | #0605? March/April 81: Portable* Music Issue, reviews of technical information ranging from design and construction Remco's FX, E-H mini-synthesizer, Casio VL-Tone, plus mods of Craig Anderton's AMS Modification System to modifying and for the M-10, GR-500, mini-amp, and the Korg X-911, customizing some of the most popular audio effects and Introducing; Practical Circuitry and On Location, new columns processing equipment available. □ #0606 May/June 81: Synthesizer: Hardware Mods & Don't miss out, there are a limited number of back-issue Software. Modular Synthesizer Effects, Environmental music, sets available and when they are gone they will not be Keyboard assignment for the 8700, new columns; Details, re-printed, so order yours today. Sorry, re-prints of Practical Circuitry and On Location. Volume 6 index. individual issues are not available. Device Back-Issue Set...... $18.00 ppd. V / 20 PQUPHONU July / August 1981 by B ill Rhodes So you're going to bypass the design the ad. Keep the price of major companies to produce and your records lower than the big release your own record? More gies but don't sacrifice profes power to you! But, there are sionalism in your marketing. still some complications involved Color is nice (and expensive!), with doing it yourself, so perhaps but remember that a good black- you can benefit from my experience and-white ad looks as good as with an independent record label color if it is well-designed. (Jazzical Records). • Publish and distribute Without going into recording free brochures describing what the technique, record production, jac average buyer can expect from your ket design, etc. (which is your product. Distribute these bro business) let's approach marketing chures at record shops and retail head-on. The most important as music stores if the owners are pect of selling records is adver agreeable; also try to get a mail tising and promotion. This can be ing list from whatever sources you accomplished in many ways: can and mail the brochures to FOR A COMPLETE SET OF DATA • Radio airplay is the most people interested in your record. SHEETS ON THE COMPREHENSIVE widespread device to get any prod For example, if your music is LINE OF SERGE SYNTHESIZER uct to the potential buyer's ears. keyboard oriented (which is the MODULES SEND $3 TO: Bug your local DJ with informa case with Jazzical records), get a tion, EPs, LPs, or whatever your list of keyboard players in your Serge Modular Music Systems 572 Haight Street band has recorded. Make a nui area (often available from musi San Francisco, CA 94117 sance of yourself to get the air cian union directories) and mail (415) 621-6898 play you deserve. Don't forget brochures to them. DJs are inundated with promo re • Include an address right cords by the hundreds every week; on the record jacket that people but if the DJ knows you are local can write to if they want to com talent, and you are persistent in ment on your album. With the your communications with the radio comments coming in you will have station, the chances are excellent the beginnings of a mailing list of getting airplay. to use for future releases. • Search out record or music • If your output includes stores that will accept your re more than one album, include a cords on consignment, namely, you discography of previous and "soon- give them "X" amount of records to-be-released" records on the and they pay you when the albums album jacket back. This is free are sold. But remember, your advertising and the DJs can use success is proportional to adver this as reference in selecting tising and publicity. Make an other tunes for airplay. extroverted poster dealing with • Have patience, make a your product and submit it to each trillion phone calls, try to get store with which you wish to ad free advertising any way possible vertise. (giveaways to radio stations are • Contact local radio sta extremely useful in promotion), tions about advertising your re and spread the word to anyone in cords on the air. Most stations the media. offer surprisingly low rates at So much for marketing; now night (not prime time) for 30 and for one last word of a more tech 60 second spots. Extract material nical nature, concerning pressing from your record that is easily plants. One of the most compe remembered after only a cursory tent, prompt, and interested Programmable. listening for the ad, and get a plants I've found is QCA Custom RMS has something new. pro to do the voice-over to give Pressing (2832 Spring Grove We've added new features, the spot a professional veneer. Avenue, Cincinnati, OH 45225). modules and improvements to make • Mail-order advertising They are primarily geared to inde the Aries a great programmable, through a magazine can be extreme pendent labels with small re modular synthesizer. ly profitable. Polyphony is great sources, and their prices are And it's affordable. for marketing independent elec extremely competitive. Contact tronic music because the reader- Keith Myers in your correspondance miBL ship is geared to that progressive and you will get excellent re 48 Brighton Avenue #11, Boston, Mass. 02134 niche. Use your head when you sults . C t POUPHONU July /August 1981 21 FENDER AMD MOD by Lee Powell » T 1 i 1 * i t 0 © . © © © © © - i Many Fender amplifier owners master volume controls, using a have wanted to reproduce the full- shamelessly simple trick. Figure blast sound of the amp, but at 1 shows a simplified drawing of lower volume levels. Adding a the output and driver stages of a master volume control accomplishes typical 50 Watt Fender amp (100 this purpose, as it can lower the Watt Fenders are basically the final sound level, allowing the same, but include two extra power original volume control to be tubes in parallel with V7 and V8. cranked up to 10. This modifica Smaller amps - except for the tion has become so popular that it Champ - have similar circuits as is built-in on the newer Fender well). V6A and V6B are connected amps. as a differential amplifier, sup Periodically, technically plying a pair of balanced signals inclined guitarists ask me for to the inputs of power tubes V7 schematics to Fender's updated and V8. The outputs of the power circuit so that they can "upgrade" tubes are developed in the primary their amps. But when you look at coil of the output transformer, the revised circuit, the design is whose secondary coil connects to so confusing that, at first the speakers. To install a master glance, it appears they may know volume control, all that is neces something that we don't. Surely, sary is to connect a 500k audio X reasoned, there must be some pot across the inputs of V7 and urgently compelling reason for V8! using such a monstrous part as a As shown in figure 1, the center-tapped potentiometer into 500k pot connects between the two which has been grafted a pushpull 1.5k resistors wired to the inputs DPST switch (available only from of V7 and V8. These two resistors Fender by special order through an are mounted between pins 5 and 1 authorized retail store). And the of the tube sockets for V7 and V8. macabre use of feedback into the Wires from pin 1 of each of these reverb tank...obviously that must tube sockets can be traced to two impart some kind of startlingly solder grommets on the circuit unique texture to the sound. Plus board, directly behind the BASS there is the mysterious connection control of the VIBRATO channel. of the master volume pot into the These grommets provide us with power amp feedback loop from the convenient terminals for connect output transformer...hmm... ing the two wires from the 500k In spite of the unknown ad master volume pot. vantages of Fender's elaborate The master volume pot itself design, independent technicians is usually mounted in the hole have for years been installing previously occupied by the tremolo Fender is a registered trademark of CBS Musical Instruments 22 PQUPHQNJ July / August 1981 INTENSITY pot, which is then distorts both the VIBRATO and ter volume control affects the exiled to some lonely spot on the NORMAL input channels at the same VIBRATO channel only. rear panel, and henceforth ig time. This means that the NORMAL Figure 2 shows the final gain nored. Some guitarists, after channel can't be used, to amplify stage of the VIBRATO channel in a years of relentlessly boycotting another instrument along with gui typical Fender amp (Fender amps the unique tremolo capabilities of tar, since serious intermodulation that don't have built-in reverb do their amps, take this opportunity distortion would result. To over not have this stage, and are not to eliminate it entirely by sol come this difficulty, I have de good candidates for this type of dering the middle terminal wire to veloped an alternate master volume master volume control). At the some nearby ground connection, and scheme, which produces distortion input of tube V4B, the ordinary ditching the pot. Others, caring in the final amplifier stage of sound of the guitar from tube V2B less for cosmetic appearance than the VIBRATO channel alone. Since is mixed with the sound of the total access to all controls, wind the signal from the NORMAL channel reverb from tube V4A. The output up drilling a hole through the does not pass through this tube, of V4B is then mixed with the front panel nameplate, mounting it remains undistorted and signal from the NORMAL channel the master volume pot there. True operates normally. Thus the mas (V1B), and sent to the power amp. to its reputation for standing up under abuse, the Fender amp thus mutilated does not seem to suffer in resale value. Alternatively, for those gui tarists who are not sure why they wanted the master volume control in the first place, you can mount it in the same inconvenient spot on the rear panel that is usually reserved for the neglected tremolo INTENSITY pot. This will make it to quite difficult to adjust during power performance. Whatever you do, however, twist the master volume pot wires together in the same fashion as the tube heater wires. Omitting this crucial detail would violate a long-standing tradition - and leaves the unmistakable mark of a non-professional job. As popular and effective as this modification has proved to be over the years, one drawback is that the master volume control POUPHONU July / August 1981 23 Figure 3 shows the same cir cuit modified to include a master volume control (new components indicated by *). In order to increase the signal strength at the input of tube V4B, the grounded 220k resistor at pin 7 in figure 2 has been removed. The REVERB control has also been changed from a 100k to a 500k linear taper pot, so that the ordinary signal from V2B will receive less attenuation when only small amounts of reverberation are needed. The 100k resistor at the wiper of the REVERB pot prevents the output of V4A from distorting when the control is set close to zero. When the master volume con trol is rotated clockwise to 10, negative feedback through the 8.2M resistor reduces the gain o.f the amplifier stage so that the signal nal from V1B since its impedance drilled nearby into the top cir level at pin 6 is the same as it is only 100k. cuit board layer so that the free was in the original circuit, thus A side effect of the use of a end of the. 8.2M resistor can be providing normal operation. As master volume control is lack of the master volume control is re brightness when the original vol ^original capacitor duced, less feedback flows through ume control is turned up close to the 8.2M resistor, increasing the 10. To remedy this problem, the gain of V4B, which overdrives its original SPST BRIGHT switch (in — ----d. T0P l-L output when the signal level is the VIBRATO channel) is replaced high enough. At the same time, with a DPDT switch, with one half A L 12k resistor the output signal to the power amp of this switch replacing the ori i r is reduced, resulting in less ginal BRIGHT switch circuitry, and the other half switching a 1200 pF volume. The position of the mas Fig. 5 1 h^CJl200 pF ter volume control has negligible capacitor and 12k resistor across Vv capacitor effect on the NORMAL channel sig- the master volume pot as shown in figure 3. This produces more inserted into it. This will pre brightness as the master volume vent the resistor from swivelling control is turned down. As a around. Also, I generally use final precaution against oscilla shielded cable to make connections tion, a 5 pF 400 Volt capacitor is to the master volume pot, since soldered directly to terminals 6 this part of the amp is more like and 7 of the V4B tube socket. ly to pick up hum than the section The 100k 1/2 Watt resistor at illustrated in figure 1. the wiper of the new REVERB pot should be mounted on the pot it Fender amps have traditional self. Figure 4 shows how this ly been very popular, and have resistor can be physically sta inspired much loyalty among musi best reputation in the world. Their bassy bilized by pressing the right-hand cians. But just wait until you “twang” is only a rough approximation of add this modification; that black natural room acoustics. That’s a pity because and silver box will really sing. it means that many people will dismiss this exceptional product as "just another spring reverb". And it's not. In this extraordinary P .S . At this point, I sus design Craig Anderton uses double springs, pect that some readers, intent on but much more importantly “hot rod's" the producing ever more excruciating transducers so that the muddy sound typical sounds from their amps, will ima of most springs is replaced with the bright clarity associated with expensive studio gine that they can combine both plate systems. master volume schemes into one Kit consists of circuit board, instructions, amp. Unfortunately for their pur all electronic parts and two reverb spring poses, this will not increase the units. User must provide power(±9to 15v) amount of distortion that can be and mounting (reverb units are typically mounted away from the console). obtained from either of these terminal of the pot down on top of modifications alone. Guitarists [B^EIecfronics, Inc.] the body of the resistor. who seek to explore the limits to I Dept. I1 y . 1020 W. Wilshire Bv. Oklahoma City. OK 73116 [405) 043-96261 The 1200 pF capacitor and 12k which their Fender amps can be l I Send the 6740 REVERB KIT $59.95plus 1/2 Watt resistor can be mounted abused are advised to locate a shipping for 2 lbs. enclosed or on the DPDT switch as shown in service technician who is willing I I Send Free G figure 5. The 8.2M resistor to wire up the NORMAL and VIBRATO name. should be mounted on the circuit channels in ser ies...al though the addri board at the junction of the 3.3M resulting sound can also be close and 470k resistors at the input of ly approximated with two or three city. ~ state -Z'P- V4B. A tiny hole should be inexpensive fuzz boxes. C ^visa__ me__ card no______■ 24 POUPHONU July / August 1981 Taking control of your Phase 1CDO •k trademark of MXR Innovations, Inc. by Matt Richards How it works. The amount of phase shift is controlled by the I've owned an MXR Phase 100 amount of current flowing through for about 5 years now, and consi the LEDs in three dual opto-isola- der it one of the best phase tors. A Darlington transistor shifters around. However, the pair controls this amount of cur sound of a phaser whooshing back rent; in this mod, we break the and forth without regard for the connection between the LEDs and rhythm of a piece of music can get the controlling transistors, subs a bit tiresome. The answer is tituting a pot for the transistors foot pedal control, and this mod to give us manual control over the shows you how to do it. phase shift. Mounting this pot in a footpedal gives us footpedal control. The modification. Look at the foil side of the circuit to burn out that opto-isolator! board, with the wire connections With SI in position 1, you on the bottom; the upper left hand will have the standard phase corner should be marked P100. shifter sweep. In position 2, the Figure 1 shows a detail of this potentiometer will control the section of the board. Cut the phase shift sweep. If you mount trace between points A and B as this pot in a footpedal, don't shown to disconnect the opto- worry about noise pickup on the isolators from the driver transis line to the pedal, since this part tors, then connect up points A and of the circuit does not carry any B to the circuit in figure 2. audio signal. Good luck- I hope Work fast when soldering, espe you enjoy being able to control cially point B - you wouldn't want your Phase 100 as much as I do. V These new stomp boxes from PAIA are designed to give electronic guitarists the highest quality effect at the lowest possible price. Cases are formed of heavy steel and covered with the most scuff-resistant baked-on finish available Both feature heavy duty switches tor long life and electronic effect switching for pop-free punch-in and punch-out Both are high input impedance, low output impedance, non-inverting, low noise devices designed to meet all proposed FX standards Each provides hour after hour of operation from a single 9 volt battery and provide automatic power switching you II never have to worry about forgetting to turn them off No. 5720 MOJO Filter Kit $34.95 Assembled $49.95 (3 lbs.) No. 5710 HOT LYX Sustain Kit $34.95 Assembled $49.95 (3 lbs.) PART OF THE NEW GENERATION FROM 1020 W. W ilshire , Oklahoma City, OK 73116 (405)843-9626 SUBSCRIPTION RATES U.S. F one year $ 12.00 two years $ 22.00 Name [ I Send No. 5710 Hot LyxSustain □ Send l~l Send No. 5720 Mojo Filter FREE □ Kit -$34.95 □Assembled-$49.95 each l+$3postagel enclosed. CATALOG C ity:______ VISa D Mc D Card no.: Electronics, Inc. , dept11- Y , 1020 W. Wilshire Blvd.. Oklahoma Citv. OK 73116 POUPHONU July / August 1981 25 TTfTCTftTTS- The Story of Gozinda & Gozouta The not-so—balanced input. Balanced inputs are The difference is the output impedance of the a thing of beauty. Magic, really. They take two driving circuits. If it is zero (wistful thinking) signal lines and amplify only the difference between then an unbalanced input impedance is not a problem, them while rejecting anything that is common. Neat. since the impedance of the connected lines is zero The common stuff is all the garbage induced in the and nothing will be induced. As the output impe lines as they dutifully connect two pieces of equip dance is increased, then so is the impedance of the ment. Hum, noise, your un-favorite radio station, connected lines. If it is equal, then what is local police and CB radio signals, radar, fluores induced will also be equal and the common mode cent lights, life itself - all competing to violate rejection of the circuit will not allow the garbage your pure signal as it tries heroically to traverse to pass; however, if the output impedances are fair from one piece of gear to another. ly large (several hundred Ohms is plenty) then the Many solutions exist to accommodate balanced mismatch in input impedances will now cause the inputs. Transformers are the most common, and the connected lines to have unequal impedances and the most expensive, and the most troublesome. So much induced garbage will not be common, but different. for transformers. This is then converted as signal and everything goes Transformerless balanced inputs. Heading the to Hell. Hence, the popularity of instrumentation list of transformerless balanced inputs is the sin amplifiers with their equal input impedances. But, gle op amp difference amplifier of figure 1. From all is not lost - remember the one exception? It turns out, in general, that if RI = R2 (not R3 as previously stated) and R3 = R4 then you also get a unity gain difference amplifier, and, specifi cally, if R2 = R3 + R4 then you get a truly balanced input amplifier with unity gain (it doesn't work for gains greater than unity - sorry). Letting RI = R2 = 20k Ohms and R3 = R4 = 10k Ohms satisfies our requirements and yields equal input impedances of 20k Ohms to ground for each leg. The answer to the not-so-balanced input stage is so obvious that most designers have missed it (or ignored the problem) for years. Now, you have the heart of a general purpose balanced input stage that, with a few embel lishments, will serve for any projects you may have requiring balanced operation. RI here the solutions expand (as does the cost) to two and three op amp instrumentation amplifiers. The main advantage of the more complex circuits is their equal input impedance characteristics. A character istic not exhibited by the single op amp difference circuit, with one exception. Patience, I'm getting to it! Back to figure 1. If RI = R3 and R2 = R4, then the circuit amplifies the difference between the inputs by the factor R1/R2, i.e., Vout = R1/R2 (Vin+ - Vin-) Any signal common to both inputs will not be amplified at all, providing all resistors are per fectly matched and you are using a decent op amp. More on this later. For unity gain applications, all four resistors will be equal, and the circuit performs the impor tant task of converting line level balanced inputs to single ended outputs, and is probably the most commonly used circuit for signal processors. So Figure 2 shows a complete balanced stage with a what's the problem? Unequal input impedances, stereo 1/4" phone jack input. There is a bit of that's what. cleverness going on here that comes for free. Using Looking into the negative port, the input impe a stereo phone plug into the stereo jack gives you dance seen by Vin (-) is R2, while Vin ( + ) "sees" R3 the balanced line input - obvious. Not so obvious + R4 as its input impedance. Typical numbers would is that by using a mono phone plug, the circuit be for all resistors to equal 20k Ohms, therefore automatically switches to unbalanced single line the negative input impedance is 20k Ohms to ground, operation. Nice, huh? What happens is that the while the positive input impedance is 40k Ohms to ring of the jack gets shorted tc ground by the mono ground. Why is this a problem? It isn't, for some. plug and turns the difference amp into a non-invert For others, it creates a system full of humming ing stage with a gain of two, but there is a 6 dB birds. pad hung on its positive input, so the net result is 26 POUPHONy July / August 1981 by Dennis Bolin a gain of one, unbalanced input. The stage becomes other, more complicated schemes involving reverse even more universal now, being either balanced on feedback circuitry to guarantee that the differen unbalanced, depending only on whether the input plug tial output signal is virtually immune to loading is stereo or mono. effects (using at least four op amps), but each of Trimpot R3b is added as a "tolerance soak", these circuits share the same problem - they all since this one adjustment will soak up all of the reference their outputs to the amplifier ground - a resistor mismatches. A common mode signal is ap definite no-no for hum-free systems. plied to the inputs (e.g., tie both inputs together The best solution, as is so often true, is the and drive with a signal generator set for 2 Volts simplest. It is no more complex than figure 4. By output and 1 KHz) and R3b is then adjusted for minimum output. One percent resistors are required if any kind of decent common mode rejection is to be gained, since any mismatch will cause a common mode input signal at the resistors to appear as a dif ference signal at the actual op amp input terminals. So much for down and dirty balanced inputs; now how about an equally dirty "balanced" output that will blow the socks off more elaborate versions? The not-so-balanced output. Balanced outputs have evolved in a similar fashion to balanced in puts; starting out with everything using transform line drivers taking a regular single-ended (unbalanced) line driver and floating its output and ground, you create a compatible system for driving differential (balanced) inputs that is trouble-free. Figure 5 snows the interface between the two systems. Note that while the chassis of each unit may be at the same potential, their signal grounds are allowed to be at different potentials. This is very important in keeping hum common mode, and not differential. Any difference of potential existing between the two grounds is seen as a common mode signal and is rejected. Like the balanced input stage of figure 2, the "balanced" output stage of figure 4 automatically switches to a conventional unbalanced output stage if a mono phone jack is used for interconnection. The ring of the jack gets shorted to the sleeve, thus grounding the sleeve as you would in a normal balanced system. ers and gradually moving toward transformerless So, there you have it: A universal input/out- solutions. The most commonly seen solid-state cir put scheme that is balanced or unbalanced, depending cuit involves two op amps as shown in figure 3 (or upon the required application...just like apple pie some variation of this configuration). There are and cheese.Q line driver UNIT 2 uuirui INPUT ►— l------1 ^V^output — ------| av ; , r m g ■ ■ ring I-- NC • ..... ------_ _ _ II------•-- 1 Indifferencedifference sleeve sleeve anrolifieramplifier signal (s.ee fig. 2) rU ground chassis ground Figure 5 Interconnection between units ...... ^ pourwowy July / August 1981 27 MORE------1 GB.-SOO Comments and Mods by Robert D. Loney some funny sounds when the string vibration dies out and glitches to a halt. We suggest, therefore, that Here are some comments on some of the more the bridge and nut not be replaced. popular GR-500 mods, specifically Gary Cowtan's mods Pickup changes. Changing the low impedance described in the March/April issue of Polyphony, as stock pickups to high impedance replacements also well as comments on some other possible mods. interacts with the infinite sustain system. When Understanding infinite sustain. One source of the audio current first flows in the string, a click confusion to the would-be modifier is the infinite noise is generated which is de-emphasized by the sustain system. This is an electro-mechanical sys lower output pickups. With higher impedance pick tem made up of a hex pickup, buffers, hex switch, ups, this effect can cause an audible click noise filters, string current drivers, the strings them problem. Theoretically, increasing the pickup sig selves , the permanent magnet (in that black box at nal and decreasing the subsequent buffer gain should the base of the neck), and the frets (which are maintain the same signal-to-noise ratio, but under purposely grounded). If you have synth or dual some conditions the problem persists. Therefore, selected on the gtr/dual/synth switch and fret a anybody who wants to change their pickups should be string, not only are you selecting a pitch, you are prepared for some experimentation and comparisons. closing a switch which forms a close looped circuit. Guitar output jack. This would be a very use More specifically, the string vibration is converted ful modification, but unfortunately, we have not to an electrical signal at the hex pickup, and then developed, nor have we seen, a well designed and passes to a hex buffer (made up of 1458 op amps). documented modification along these lines. Anyone The 1458 outputs go to two places; one path leads to who has figured out how to do this is encouraged to the 24 pin connector and control panel, the other send their plans to RolandCorp US (2401 Saybrook path goes to another set of buffers. From those Avenue, Los Angeles, CA 90040; tel. 213-685-5141) buffers the signal passes along to a TC5012, which and to Polyphony so that this information can reach is used as a hex switch in conjunction with the other interested GR-500 owners. gtr/dual/synth switch. From there the signals pass Speeding up response time. There is a certain to a hex filter and then to the string drivers portamento phenomenon which is most noticeable when themselves. using some left hand playing techniques with the At the point where the string vibration would solo melody or external synth sound sections. This normally begin to decrease in amplitude (because of effect is caused by a control voltage gate circuit friction and so on), a few microAmps of current which averages the CV change unless the string is begin to flow in the string itself. Bear in mind retriggered by a picking technique. The RC averag that this is an audio current. On its way to ground ing circuit that does this, which is necessary for at the selected fret, this current generates an pitch stability in normal operation, is unnecessari electromagnetic field corresponding to the audio ly slow. The resistor in this network can be current. The AC magnetic field interacts with the changed from its present 220k to 180k or possibly permanent magnetic field (from the black box), in a 150k. This will not completely eliminate the ef positive feedback mode, to create a sort of solenoid fect, but it will speed it up significantly. The action by the string. All of this acts to maintain resistor to be changed is difficult to locate. For string vibration, as long as the string is fretted those interested in trying this modification, call properly. or write RolandCorp US asking for technical assis Bridge/nut modifications. With the above in tance and request the information for the GR-500 F formation in mind, consider what happens when you to V circuit mod involving the CV gate RC averaging replace the bridge and nut with heavy mass, brass circuit. types. The audio current travels down the string to One last tip: As Gary Cowtan says, change your the brass bridge, where it is shorted to the other strings often. This not only maintains a bright low impedance sources (which are either quiescent or sound for the guitar section, but also ensures a vibrating at some other audio frequency) via the good string/fret contact which minimizes triggering conducting brass bridge. This effectively disables and sustain problems. the infinite sustain system. A brass nut (zero fret) causes essentially the same problem. Strange (Robert Loney is a previous Roland service depart ly, the symptoms of this problem are not noticed ment manager currently contracting his services to ^ right away; yet sooner or later, the player notices that company.) C 28 P0UPH0NLJ ■July / August 1981 Proteus I patches thanks to Scott Lee, A d v e rtise PAiA Tech Service. ■O O Phased Fuzz Guitar I LFO patched to No. 2 of PW Mod ------O O— -i O ' , Q 0 a d C 5 Q ! Index I n l o j 0 O T E Blacet 29,34 D G © 0 Q 0 0 ' E Dickstein Distributing 12 COARSE FINE W F ** AOSR """ MOO m“ EMSA 34 I Q s □ ! ° i ° Godbout 11 j o . 0 0 0 j D Q j PGS 15 Phased Fuzz Guitar II ADSR patched to #2 OSC PW Mod Paia Electronics 5,24,25,36 n r PolyMart 18-19,20 © 0 0 0 0^0 Q 0 I n ' OCTAVE Rivera Music Service 21 L ...... P . L 2 po.1 1,0 ^ ^ Sequential Circuits 2 © 0 0 © Q 0 G i © COARSE FINE WF FIL ^T-I. "«* A0S" """ MOO i n Serge Modular 21 i p TEAC (Tascam) 6-7 ! o □ 1 o 0 1 0 0 | ADVANCE * ■* nofm PROGRAM L| q ATTACK 0 DECAY 0 SUSTAIN . RELEASE AA FREQ | >> THE TIME MACHINE.™ A REMARKABLE VOLTAGE CONTROLLED TIME DOMAIN PROCESSOR FOR THE SERIOUS MUSICIAN. * Voltage Control of ™e,n m i- ; m - i e him -:™ Ail Major Functions. BLACET MUSIC RESEARCH (Industry standard 0-10V) Delay £ SIGNAL LFO RATE LEVEL Cancel LFO Rate MODULATION ■ REGEN m LFO RST 4 OOmS Modulation Depth ***> Regeneration o o ☆ Envelope Follower 0 0 o P i i 2 OO m S i i INT • EXT ☆ Modulation CV Mixer i i RANGE RATE DEPTH CV MIX i * Delay: 200 mS/5KHz ■ ■ ■ 1 1 1 I | | 400 mS/2.5KHz 1 1 ■ i ■ ■ ☆ Curtis VCAs, Bi-Fet Op 1 i 1 1 Amps, Brkkwall Filters, * \ ■ 1 I 1 * i ■ ■ Compander, ± 15 Volt, & & $ W' o P 6" x 10" x 3*. IN C A N C E L C V RST ENV CV E X T O U T CV ☆ Complete Kit: $248 (until OUT MOD. 12-1-81, $298 thereafter) The Time Machine is a lot more than just another analog delay. We’ve recognized the power of DYNAMIC control of delay and designed a processor to take maximum advantage of your controllers. You can use the self-contained envelope follower and LFO, or, external synthesizers, footpedals, computers, etc. Consistent quality throughout. Order today! Add $5 S&H US, Canada, Mexico; $15 elsewhere. CA, add 6%. MC/VISA OK. BLACET MUSIC RESEARCH • 18405 Old Monte Rio Road • Guerneville, CA 95446 POUPHONy July/August 1981 29 Flora & Fauna of the Patch Cord Jungle ------\ MODULAR SYNTHESIZER EFFECTS: PART II bvJim Aikin (In last issue's installment, Jim started off by giving some opinions about the current state of the synthesizer art, and why the synthesizer - which should be one of the most versatile instruments in existence - is often one of the least versatile. To recover that missing versatility, Jim delved into such subjects as the difference between imitative and non-imitative synthesis, percussive synthesis, animation of musical sounds, bell effects, and more. This installment concludes the article by covering additional examples of both imitative and non-imita tive synthesis, as well as an extensive discussion ______on how to get the most out of LFOs.) known. They sound haunting and mysterious, yet elusively familiar. That is, they have an emotional meaning that communicates with the listener on an unconscious, pre-verbal level, even while the con Other Examples of Imitative Synthesis. Imita scious mind is unable to exactly identify the nature tive synthesis can involve sounds other than percus of the sound. sion. Crickets, for example, are easy to imitate. Before leaving the subject of imitative synthe Because a cricket starts and stops its chirp sudden sis, here's some advice for anybody who is tempted ly, a square wave LFO is ideal for opening and to imitate wind sounds: Don't. Wind (and its first shutting the filter or VCA. Use two oscillators in cousin, surf) has become one of the instant cliches the 600 - 800 Hz range, tune them a half-step or so of electronic music. If, in spite of this caution, apart, and modulate them with a fast sine wave LFO. you feel you've got a valid artistic use for wind, The modulation should be somewhat deeper than or it's not hard to make some. Just feed some white dinary vibrato - a whole-step or so. Inverting the noise through a filter and modulate the filter with LFO on the way to one of the oscillators will help a slow sine wave LFO to simulate the rising and fatten up the sound, as will setting the two LFOs at falling of the wind (see figure 4). A filter with slightly different speeds. voltage-controlled resonance would be especially One other thing will help your crickets a lot: useful for this patch, because as you raise the Use two or three of them at once, chirping at dif cutoff frequency you can increase the resonance with ferent speeds. (Multi-tracking becomes indispen the same sine wave, giving the filter a slight sable at this point.) Set the crickets at different shriek at the top of its rise. In addition to the volume levels, and give the quieter ones more re noise, you might also want to mix in a couple of verb. Presto - instant summer night. Tricks like low-pitched oscillators at low levels for the wind's this will often give the listener the impression moan. Modulate these with the same slow sine wave that the patch is very realistic, even if one of so their pitches will rise slightly as the rest of your "crickets" by itself isn't an especially good the wind rises. likeness. This is an important principle of imita The other important characteristic of wind is tive synthesis: If a sound is behaving like the that it's irregular in period. Rather than use a acoustic sound it's intended to imitate, the ear sine wave LFO at all, you might prefer to use a will tend to assimilate it and identify it with that joystick or some other manual controller to modulate sound. If you have your bells strike the hour the all these functions (filter cutoff, resonance, os way the tower bells at college do, they'll sound cillator pitches) simultaneously. The wind some more realistic than if they just strike a note or times has sudden surges, sometimes dies away into two at random. the distance, and sometimes rises to a sustained Another important point is this: Some of the howl. If you do use an LFO, to avoid an overly things you try in the course of setting up an imita predictable sound you could lay down several tracks tive sound patch might not take you in the direction of wind with different LFO speeds, or change the LFO of a realistic sound. But, bear in mind that the speed and modulation depth by hand. sound you discover just might be more useful music ally than the realistic sound. Some of the most Basics of Non-imitative Synthesis. The key to evocative sounds are the ones at the border of the good-sounding non-imitative effects is really very V y 30 PQUPHONU July / August 1981 simple: Just plug various things into one another sizers, are a rich source of modulation. One of the and see what happens. When you find something that simplest and most interesting things you can do with sounds promising, start thinking about ways to fat a modular-type synthesizer is to control an oscilla ten it up. Generally, my non-imitative effects tor with an LFO and control the LFO with something patches seem to use every function on the synthe else. Here's a simple example: Take the standard sizer and every patch cord in the house, because I envelope that's triggered when you hit a key on the can't help but wonder "now, what would happen if I keyboard, and use that to modulate a sine wave LFO hooked that up to it?" Of course, simple effects (see figure 5). Now you have a vibrato that instead can be very effective too, maybe even more effective of being static and mechanical-sounding speeds up at in the context of a whole arrangement. The point is the beginning of the note and then slows down as the just that you'll discover more if you indulge your note dies away, more or less the way a violin player curiosity and don't have too fixed an attitude about f \ what is, or isn't, possible. After you've been working with your synthesizer a while, you'll develop a feel for what connections are likely to lead to interesting results. But even then, you may still not know in advance what the patch will sound like when you've hooked it up. The fact that a modular synthesizer set-up retains its power to surprise the user with new sounds is one of its most important and enjoyable features. All the patches dealt with below are things 1 came up with in this seemingly haphazard intuitive fashion. They sound good to me, and they may give you some ideas of your own, but the only way you're really going to learn about synthesizer effects is to spend enough time with your equipment to develop an understanding of what sounds good to you, and how to go about getting it. In the preceding discussion we've already touched on several ideas that are just as useful in non-imitative as in imitative synthesis. Perhaps might impart vibrato to a string. Or, you could the single most important idea is this: Oscillators invert the envelope voltage so that the vibrato can be modulated by an enormous variety of control speeds up as the note dies away. If you're for voltages. What's more, these voltages can be pro tunate enough to have a velocity-sensitive keyboard cessed in a variety of ways before they ever get to and a voltage-controlled envelope generator, it's a the oscillators. Oscillators can be modulated by simple matter to control the vibrato speed directly other audio oscillators to produce complex tone from the keyboard as you play. colors (this technique is used a great deal in Some other choices for modulating the LFO in digital synthesis, where it is referred to as FM - clude another LFO to change the vibrato speed in a frequency modulation). Two or three tone oscilla regular way, or a random sample-and-hold to change tors can be modulated by different voltages; by it in unpredictable ways. And, all this assumes envelope voltages so that they rise or fall during that you're using the LFO's sine or triangle output the course of a note, by noise to turn them into to modulate a tone oscillator and generate vibrato. pitched noise, and of course by the ubiquitous LFO - You can just as easily use the square wave output to which we will now investigate in some detail. create trills in the same variety of patterns, or the sawtooth output to create - well, sawteeth. Or LFO Techniques. Voltage controlled LFOs, which you can apply the LFO voltage to some other module, are unfortunately rare on "live performance" synthe- such as the VCA, to produce volume swells...... 11 Modulating the LFO with two other LFOs will . " "give it a complex periodicity that hovers at the edge of being comprehensible, with results that can be either hilarious or somewhat disturbing. This will probably sound best when applied to a sustained oscillator tone rather than to a series of discrete notes. In other words, we're no longer talking about playing traditional music on a keyboard but pure electronic sounds. If we go on to route the LFO through a VCA before it gets to the tone oscil lator, so that the vibrato will change in amplitude as well as in periodicity, things will start to get quite interesting. This kind of patch seems to work well when the same LFO is also modulating the filter and there is enough resonance in the filter to give it response peaks corresponding to some of the formant frequen cies of the human vocal tract (see figure 6). Don't worry if you don't know what these formant frequen Figure 5: Expressive Vibrato cies are - just nudge the filter cutoff frequency and the modulation amount until the filter starts to talk to you. If you've got the patch hooked up V. right, the filter should start to say, "Wow! POLJPHONJ ------July / A ugust 1981 31 Ooohhh, Wow!" No kidding. Last week I had a patch [ like this saying, "I want to be free! I want to be free!" Of course, much of this is in the ear of the listener; you might have heard the same patch saying something different. When it comes to non-imitative synthesis, subjectivity has a wide open field. Okay, now that we have the LFO behaving in a fairly idiosyncratic way, let's use it for something besides modulation by tapping into the square or sawtooth output and using this is a clock to trigger the sample-and-hold (S/H). The S/H has become an other of the cliches of electronic sound, but only in its simplest form (the only form accessible on most inexpensive synthesizers). When the S/H clock is ticking at a regular pace, usually fast, and sam pling random noise at its input, what we get is the Figure 8: Sawtooth S/H with Evolving Phase familiar random stepped voltage output. On a typi cal small synthesizer this can be applied to control V the oscillator pitch or the filter cutoff frequency, front panel, it can just as easily sample any other and that's about it. voltage we feed it. One of the most musically Let's hook the S/H to the oscillator (with any useful inputs turns out to be a sawtooth LFO. When LFO disconnected for now) so that we'll hear the the sawtooth is somewhat slower than the S/H clock stepped voltage as pitches, but instead of using the (we're back to the normal regular-pulse clock regular S/H clock, let's trigger it with our synco ticking again now), the S/H output can feed a tone pated LFO clock. The same clock should also be used oscillator to create a scale-like staircase pattern. to trigger the envelope that shapes the notes. The A sawtooth below 1 Hz and an S/H clock around 20 Hz notes will have a more or less humorous effect as will give us a flutelike flourish that has the they bounce from one pitch to another at an unpre advantage of not suggesting any specific tonality. dictable rate. Fed through an echo machine, such a flourish might be just the thing to lead into a higher-energy \ section of a piece. As we speed the sawtooth LFO up, the steps of the staircase get further apart in pitch, and there are fewer of them in each rising (or falling) cycle (see related article in this issue - Ed). When the frequency of the sawtooth is less than twice the frequency of the clock, the staircase disappears, to be replaced by a phase interference pattern that is the aural equivalent of a moire pattern (or, a com plex version of a Mozart alberti bass pattern). The finishing touch on this patch is to modulate the sawtooth LFO with a very slow sine wave LFO, causing it to change speed while the S/H clock stays steady (see figure 8). Now the alberti bass pattern, in stead of repeating, will constantly shift, adding Figure 7: Syncopated Sample and Hold notes to make longer and longer arpeggios, then breaking into a microtonal scale that swoops down and back up, and so on. All by itself, the synthe sizer is playing notes that seem to fall into mean ingful patterns - though, as in the case of the Now, disconnect all the other modulation inputs "speaking" filter, it's the listener who creates the to the LFO, so it's pulsing regularly again, and meaning by grouping or interpreting these sounds. then hook the random stepped voltage output of the I've always thought that three or four tracks of S/H back up t£ control the LFO (see figure 7). This this kind of shifting pattern would be great for a will have an immediate and perceptible effect; The fadeout on a fast, happy tune, but if you try it higher the random step, the faster the LFO will out, you might find some better use for it. hurry to its next tick - and thus, the higher the note sounded by the tone oscillator, the shorter the Non-Imitative Percussive Techniques. Just note will be, while the lower the note, the longer about any combination of oscillators, ring modula it will last. This is a psycho-acoustically power tion, and noise can be fed into a filter with a ful patch, because the high/fast - low/slow priority cymbal-like envelope to create an ugly mechanical is found in much of traditional music. Think how burst. Or you can leave the filter's initial level many sixteenth-notes the violins in an orchestra high enough that sound always comes through, and play, as opposed to how many the double basses play. modulate it with a repeating envelope for a nerve- Now that you've heard this effect, hook the wracking machine drone. LFO's sine wave output back up to the same oscilla For something not quite so bizarre, turn the tor. If all goes well, it should begin to moan and resonance on a filter up until it almost feeds back, hiccough in a positively eerie fashion. and use an LFO square or sawtooth wave as an audio The S/H is capable of some other tricks that (not a control) input to the filter. The sharp edge you may find useful if you're tired of the same old of the LFO wave will make an audible click, which synthesizer sounds. So far, we've only had it sam the filter resonance will draw out into a kind of pling noise to create a randomly stepped output. metallic tap or woodblock-like knock. Tune it by But if it has an appropriate patch point on the adjusting the filter cutoff frequency, and change V 32 POUPHONU July / August 1981 the rhythmic pattern by modulating the LFO. An LFO Synthesizers are so clean-sounding they some that has been randomized by modulation from the S/H times don't blend in well with other instruments (or three LFOs all modulating one another) makes a when recording. Echo will usually help this - or truly crazed percussionist. Alternatively, you you might want to run the synthesizer through a could modulate the LFO you're listening to with guitar amp and mike the amp. Basically, anything another, slower square wave LFO. If you adjust the that will introduce a touch of distortion and a levels properly, the clicks will seem to be grouped physical quality to the tone will help a lot. as eighth-notes and triplets, because the LFO you're Concerning where to put effects in a piece of feeding through the filter will operate at two dif music, it's always a temptation with any new toy to ferent speeds, one when the LFO modulating it is in use it everywhere you possibly can. But if you're the "up" portion of its cycle and the other when not careful, your arrangement might end up sounding it's in the "down" portion. Be warned, however: like a Christmas tree. The solution here is probab Once in a while, this programmed percussionist will ly to treat the synthesizer the way you would any drop a beat, because the two LFOs won't be precisely other supporting instrument. If it's an adjunct to synchronized. the drum kit on a particular tune, listen to how the Here's another idea: Use the square wave out drummer is developing his or her part, and cue in put from the second LFO (the one you're not lis your synthetic rachet or cowbell at a point that tening to) to open and close the VCA, so that you'll will make sense in conjunction with the snare drum get bursts of percussion followed by bursts of and hi-hat. When a new section of the tune arrives, silence. Then take the sine or sawtooth output of the drum part will usually change, and the synthe this LFO and modulate the first LFO with it to make sized percussion should change in response. each burst of percussion change speed. Use a lot of Like any other instrument, an effects synthe sine or saw modulation in this patch, so the LFO sizer should be applied tastefully, with an aware going into the filter will rise from a slow clicking ness of how the whole arrangement fits together. almost into the audio range before it's abruptly cut Unless the effects are the focus of the tune, the off. If all goes well, this patch should sound synthesizer should probably be used for no more than quite machine-like and ominous. three or four different types of events in any one LFOs are also extremely useful for slowly al tune. One of these events might be a major hook - a tering the tone color of an ongoing event. Let's beeping that makes the chorus so unsettling, for say you've set up a chord sequence on a three-stage, example - while others might be purely supportive 16 step analog sequencer, with each stage control and very much in the background. The same principle ling a different oscillator to give a sequence con applies to classical music synthesis; only the terms sisting of three note chords. The simplest patch is need to be changed. Synthesizer effects can be just to listen to all three oscillators all the extremely complex and alien, or they can be very time, but this can lead to aural fatigue pretty simple, but in either case it's important to remem quickly. Fortunately, there are some easy solutions ber that they aren't an end in themselves. They're to this problem. You can route one of the oscilla a means to the end of creating good music. tors through a VCA before it mixes with the other When it comes to music that's played entirely oscillators, and modulate the VCA with a slow sine on synthesizers, you obviously have more latitude or triangle wave, thus altering the amount of OSC 3 for the lavish application of effects. But even in the mix. If at the same time you use another LFO here, you'll need to consider what the character of to modulate the waveform of OSC 2, and a third LFO a given piece of music is, and which patches will to shift the cutoff frequency of the filter just further enhance that character. Is the mood insis slightly, while taking care to set these three LFOs tent and urgent? Is it murky, misty and mysterious? at different speeds, your chord sequence will begin Is it placid and pleasant? Each mood calls for to take on a great deal of life. It will be hypno different effects. In fact, a good exercise might tically repeated and at the same time it will be be to decide on an emotional meaning first and then continually varying in tone color, which paradoxi try to set up a patch to convey it. cally adds to the hypnotic effect. In the last analysis, only a thorough famili As long as we're on the subject of sequencers, arity with the capabilities of your own equipment don't forget that a sequencer clock doesn't have to will tell you how to achieve the effects you want; tick at a steady rate. With a three-stage sequen you may not have equipment comparable to what I used cer, it's easy to use two of the stages to play to set up the effects described in this article. pitches on the oscillators and the third to control But no matter how limited your equipment, by ap the speed of a voltage-controlled clock. Syncopa plying the principles I've outlined that equipment tion and odd time signatures are one possible re will probably be capable of more than you're using sult. Even more intriguing is the possibility of it for currently. So start messing with those knobs setting up a riff whose metrical values are slightly and switches. And don't forget to keep your ears off. On a digital sequencer, this is even easier to open. Q, manage - just play something with a lurching synco pation, and hit the repeat button. You'll have a hypnotically repeating pattern that you can't quite tap your feet to, like a broken record. Improvising a solo over such a riff can lead your melodic thinking into entirely new areas. Applications. We could go on listing patches, but the basic concepts should be clear by now. However, there's still the question of how to use these new sounds musically. While this could take another article in itself, here are a few random suggestions that you might find useful. rourHorjy------July / August 1981 33 EOUIPmEffl GXCHAOGE List your equipment or services for sale, trade, or wanted, plus job openings, positions wanted, and so on. Keep listings brief; enclose $1.00 for each 10 words. Prices, zip, and phone numbers count as one word each. Display classifieds are available for commercial ads; rates are $12 per column inch (minimum, camera ready). Respond directly to the advertiser. Please don't write to POLYPHONY. Polyphony is not responsible for claims made in ads, or the results of any transactions. We reserve the right to edit or refuse any ads submitted. S e rv ic e s e q u ip m e n t Job Openings Kits, parts, plans, help with IPAiA complete 8782 keyboard, a PROPHET-5 SYNTESIZER TECHS NEEDED modifications for synthesizers. cassette interface, 4 cassettes, NOW!!! Specials: 1. Convert your linear 2700 keyboard with glide, 8781, Sequential Circuits is looking for PAiA equipment to exponential with 8780, 4761, 4712, 4780, two 4770A, experienced techs who've built easy to use kit. 2. Precision 4730, two 4740, 4711, two 2720-3B, their own synthesizers and can 2720-9, 27203L, four 27202A, two VCO kits with exponential trouble-shoot to component level 2720-11, 2720-5, three 2720, responce. 3. 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Walt Whitney, 2232 Transposers, 1 Multiple/Attenuator ☆ Divide by 1 Panel, 2 Pedals, 2 Extra wing Wengler, Overland, MO 63114 (314) thru 3 and 4 cabinets, cassette and software, 429-2858 thru 4096 available cords, manuals. Excellent separately. Add $2 P&H US, condition $1400.00 invested, Hammond B3 Organ with Leslie RV122 ☆ Mixer/LP Filter Canada, Mexico; ☆ Reset $800.00 or best offer. No $5 Elsewhere. tone cabinet, Polymoog synthesizer * Easy Kit. (Does not reasonable offer refused! Ron CA, add 61(0. with pedals and case, all in top MC/VISA OK include front panel) Slabe, 26351 Lakeshore condition, no road use, reasonably BLACET MUSIC RESEARCH, 18405 Blvd.,Euclid, Ohio 44132 (216) priced. Enid, OK 405-234-3589 OMRR, GUERNEVILLE, CA 95446 261-1072 after 8pm. 34 PQUPHONU July / August 1981 Or a dog. Or violins, drums, voices, sound effects, textures. All in a compact, portable instrument that is machines, or, in fact, anything. Not synthesized incredibly simple to use and priced within the budget simulations but the actual sounds. With the E-mu of most serious musicians. Systems Emulator, any sound you can hear can be But talk is cheap. The world is suddenly full of digital digitally recorded and then played back at any pitch instruments offering incredible features Cat incredible over the range of its keyboard-with up to eight note prices).You can hear the Emulator soon at selected polyphonic capability. Instantly. music stores. Listen to it. Compare its capabilities, The Emulator opens up a new world of possibilities ease of use, and price. We think the choice will be to composers, performers, studio engineers and obvious. After all, you want to be able to play a turkey. sound effects designers. Among its features are a split Not buy one. keyboard (for the simultaneous control of two independent sounds), realtime effects wheels for vibrato and pitchbend, a built-in disk drive for E-mu Systems, Inc. unlimited sound storage, and an optional multitrack 417 Broadway, Santa Cruz, CA 95060 sequencer for the creation of complex polyphonic (408) 429-9147 / E f f e c t s K e y b o a r d s Synthesizers Com puter control / Studio electronics ✓ 7 h ia newest u. Qetthe ifouncoupon faneefpiom copy, oun ad on