6L6 Shootout: 20 Types Tested /' ft. Story of Kllpacho... Out of the Corner & Into the Limelight
le... 222 ... d LK·48 Sweet Sound for a Song
6528 MM1.'o.low... Single-Ended Amplifier Project
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Eric Barbour Wins Tyne Award Electro-Harmonix Launches New VTV Issue # 1 3 At the 38th Annual Conference of the EL34 Antique Wireless Association (AWA) on Table of Contents: Elecuo-Harmonix has announced its September 3,1999, vrvSenior Ediror new EL34EH fi rs in a Eric Barbour was awarded the Tyne which is the t line: of imp roved qual iry tubes for the year Interview with Paul Klipsch 4 Award. This award is given yea rly to an T h e EL34EH has gold-plated AWA member for recognit ion of work in 2000. screen grids, 11 [Unl':dbi-polar cathode Klipschom: Lore and Mods .. 6 documenting the hisrory of vacuum tube cover that optimilCS electron focusto the electronics. platC', p rec ision al ignmem and a propri Classic 2A3 Amplifier .....•.. l0 Mr. Barbour has wrinen sevenl art icl es erary {ri-alloy plate material the reduces Problems with Electronics .. 13 d ealing with th e h isto ry of audio and distorcion and odd-order harmonic;:s. other types of tubes for Vacuum Tube For more information, contact Electra .....•..•• Valley and Glass Audio magazines. He is Scott 222 ond LK48 15 Harmonix at: (212) 529-0466, (212) also a volunt�r for the Computer 529-0486 FAX or www.ehx.com Computing with Tubes .•...• 20 Musuem History Cente! in Mountain View, CA. He has help ed them docu Tube Collectors' A5Sociation Formed ASUSA K2003 Review.•..•.. 21 ment and reStore some of the Museum's A new Tube Collectors' Association i s historical vacuum tube COlllpmer now in operation. This is an organiza 6L6 Shootout ...... •.•••••..... 22 exhibits. Eric manages the Vacuum Tube tion of collectors focusing on all phases, Applications Laboratory and p rovi d es [}'pe5 and vintages of tube technology. 6528 SE ArnpProject...... 26 cuStomer tcchincal support for Svetlana The association publishes a club bulletin Elcctronic Devices in Portola Valley, CA. and is plan ning tube collector events, Subminiature Tubes ...•..•....28 etc. For more info, contact Al Jon es at New Contributing Editors at VIV (707) 464-6470 or Ludwell Siblc:y at We an: pleased to announce two new (541) 855-5207 or send your mail Coming In the Next contributors to Vacuum Tube Vall ey: r(!(juest to: TCA, ro. Box J J 81, Medford, OR 97525 "sue of VTV: David Bardes is a loudsp�er enthusi aSt and a DIY. Dave will be rC!learching 12AX7 Shootout Vacuum Tube Valley Moves loudspeaker history and conducting inter - Exclusive Interview with views with famous loudspeaker designers. \Ve are moving! After doing business David Hafler of Dynaco In addition, he will be th e VTV Official in Sil icon Vall ey for five rears, wc are Product Re\' iewer. In the future, we will moving the VTV office and shop to - naco Tube Products n � be conducting re\· iews of reasonably no h of Napa Valley! The air is fresher, Historical Review priced loudsp eak ers, tube: CD players and the scenery is beautiful and there is a lot - Gillum G-3 Speaker Review tube amps and preamps. Dave's back less traffic. Business will be as usual g round is in professional photography (once we get t'V erything moved) and we - Direct Reactance Drive SE and video production. He is employed as will contin ue to operate the magazine Amplifier Project a product teSter for a well-known el ec and the audio tube and parts business. u m Please nOte the follow ing address - pp SV 83 Amplifer Project on idco puter products test lab. [email protected] changes: Southern CA Hi-Fi S"Wop Ron Veil well-known guitar amplifier Vacuum Tube Valley The 4th Annual Southern California Hi-Fi Swap will lech in the San Francisco area. He served P.D. Box 1499 be held on �ril 30, 2000, ot theH olidayInn Bueoo in the US Air Force, Philips Electronics Pork, 7000 Beoch Sivd., 8ueno Pork, CA and has ten rears experience in musical Lakeport, CA 95453 USA Includes CUrref1t high·end, vintoge, ports, Iu�, etc. intrument repair and service. Ron will be Phone: 707-263-5881 vendor Iob� $40 [8:00AM $eIup), forfy admission regular tube guitar amplifica ion expert a t FAX: 707-263-7648 [10:00 ami $5, [10:00AM.) $3. Call [9(9) 931- and contr ibuto r. · em 9686 to reserve 0 table or [714) 522·7000 /ord irec [email protected] ail: triode@Vacuumtubc.com tions. www.ups EDITORIAL STAFF Vacuum Tube Valleyi s published quorterly Copyrig,t2000Vacuum Tube Valley" for electronic enthu$iasl1 interested in the and Big Tone" All rights re$E!rved. Charles Kittleson - Pubhher colorful post, present and future of vacuum No port of this f>\Jblicolion may be reprinted or otherwi$E! reproduced withovt written tube electronics. John Alwood - Technical Editor permission of the f>\Jblishe r. Subscription Role: US$45/4 issues 1 si Clau·$36 Eric Barbour . Senior Editor Sendcirculation ond editrorio[ 3rd Cion; Conodo/S48; Aiio/$66; Europe/$56 Ron Veil- Guitar Amp Specialist correspondence 10: US Bank Check, Credit Cords or Cash Vocuum Tube Valley David Bardes - Contributing ore accepted for payment. Editor P.D. Box 1499, Sieve Parr - ArtDirector Lakeporl, California 95453 USA Phone - (707) 263-5881 e-mail [email protected] FAX - (707) 263-7648 Julie P. Wemer - Copy Editor ISSN # 1095-4805 VACUUM TU II VA LLEY ISSUI 13 .. N N , E R V • W w r M P A U L K L P S C H An Interview with Paul Klipsch By David Bordes 02000 All Ri9ht� Reserved Paul W. Klipsch is an Ilud;o pitJnur who My mOlher bought 1n £discn designed and pToduud the Klipschorn Phonograph in 1923. When I folded-hor" wudspeaJur system which bas wenT home for vacation from Cow bun in production for ovtr 50 years. He College (New Mexico State), I also developed and produud uvtral Ot/UT noticed she had pur it in the cor loudsptllkusIlnd wrott doum of Ilrlicks ner. It was thl': most obnoxious and papers for audio pub/ielllions and place for it, but it sounded better societies. K[ipseh was induclld into The in the corner. Enginuring and Scimu Hall of Fame on October 16, 1997for his contributions in Later, in 1933, a fellow student acousdcJ, ballistics, and ,opbysics. This at Sranford loaned me onc of his interview was conducu'!. during the Fall 12 inch direct radiatOr speakers Voice 12 inch direct radiator, which was of 1999 with the assistllnu of Klipuh and I PUt it in an enclosure. At the sug capable of VA CUUM TUB E VALLEY S SUI I 3 A N N , • R Y • W w , . P A U L K L P 5 C H successes. But one with 2-channd stereo, right and left, and learns from failures. also 3- cha nnd, right - center - left. All were rdalively succeS5ful. From tar" KlipIChorn liura Which musicianr, movi� stars, and u/�bri tU", [ noticed that firs own or hav( owntd Kiipschorm? the mid-horn wokd {ilu a radial horn. Edwin Armsuong, inventor of the FM When and why did radio, bought 5 of Our earl)' Klipschorns, you switch to an probably Xis. He bought them to assist aponential horn? in selli ng FM. Whether it was successful in that respect I don't know. Success in The first high fre FM has taken pla ce. The conductOr of quency horn con the BostOn Pops orchestra had a sisted of a horn Klipschorn. with a radiation angle of 90 degree I nociud in som( ofthe old!iuraturt, that horizontal and 30 other companies hav( or had manufacturing degree vertical. fiuming unthr your patmes. Compani�s These were made such as Vitavox, Euctro-Voiu, Msurn with wood sides Ekctric. and the Radio Shack Corporation I was ordered to come to Hope, Arkansas and molded high and low boundaries. IWrr fi/ud. I'm awa" ofth( Vitavox, to work i n theArmy Ordnance Corps. High frequency horns have been patterned G(orgian, and Patrician corn(r horns. WnY where they tested ammunition. My d«:i· after the genel'lll structure. Tests of the thel( oth(r companirs building corn(r horns sion co Hay in Hope after the war was polar pattern of our current high frequen from JOurd�sigm! influenced by the fact that man of rhe cy horn (used in the Jubilee), show ho w r, R2dio Shack did sell a few Klipschorns buildings wouldbe sold as surp us. Mer this horn Structur� is a signifi can t that we made. Yes, we did license a small the war, I purchased the Telephone improvement over contemporary horns. number of c p nes Exchange building in the proving ground om a i . One company made a manufactured copy without whi ch COST $30,000 to build and [ bought Describe the Klipsdmrn prototypes such as a for $3,000 (it is now the museum). The rhe X2 and X3. license and advertised as an improved advantage of staning in a small building is Klipschorn (the patent had long since I but that it did not cost toO much. guess every advancement in a given art expired) the KJipschorn was a regis should have a experimental name. The tered trademark and the company was Dtscribt somt ofthi chlt/kngls ofbuilding Xl and X3 were experimental changes #2 nice enough to quit using the name and milrkrringyour businm. What wt!T'( and #3. KJipschorn. 1 bought one and tested ir. If)mt ofIhi �vi(t()rits- that occumd Rumg It had big holes in the response curves. thi way? Whrn was the first Klipschorn sold? How much didit cost? Wi" any ofJOur sptakers off(rt!daJ kiu? When you try to break into a manufac Klipschorn was 1946. t I think we made a kit for a person I ture of a new engine you have the makers The first sold in I Yes, $500 f wanted for a client. He built the box and of cxiuing e ngine s as competition. [ cost about or one. u put his own drivet in it and it probably think J enjoyed morc fai l res than J did How many KlipIChorns have bun sold? worked. I'm not particularly proud of my kits. After all, a kit is something some I don't know how many Klipschorns body putS together with a bunch of have been sold. [guess sevel'lll thousand. boards. If they fit together - fine. If they Which Kfipsch speaker has bun the mO$f don't, why, they nail them together and popular? make them fit, and then it rattles. Of all the speakers [ have built the What audio rquipmmr did JOu like orfind Klipschorn is the most successful. IWI/tnginurrd? Various smaller versions have been manu III far as «juipment, it was homemade factured by mysdf and others. amplifiers. Also, I liked an early amplifier Haw any KlipIChorns bun sold ovastas? If of 1948 vintage made by Brook. The so, which countrirs? Brook amplifier used 2A3 tubes and put our 10 Wat tS with very low distortion. I, all Yes, of the European countries, and also many sales in Asian countries and Where do you su the fotureof music "pro Afr ica. duction heading? I bt/inle that you exptrimrnud with th"� I'm not a pro phet. I thought the tape ro channtl audio. What IWrtJOur findings? recorder would solve a lot ofo ur p b Ifthis a viabk playbackformat? lems. Now we have the CompaCt Disc. Bdl Telephone Labol'lltories used 3 speakers spaced for a stereophonic sound 30 reproduction. 'did some experiments Continu�d on Pt1g� VA CUUM , UB I VALLIY I 5 SUI , 3 • K L PlCHORNS Structed the first suc;cessrul prototype, the X3. That same year, Paul applied for a Klipschorns parent on his design. At the patent office he discovered scveral other corner horn designs. Paul's design might not have been Ou' of 'he Corner & In'o 'he Limeligh' the first, but his determination and his By David Bordes �OOOAll Rights Reserved skill as an engineer made his design a suc· cess. Audio Origami developed into a working tenent in all his Paul Klipsch made audio history when designs, and a mantra that Paul still utters High Notes today: "Speaker efficiency and speaker he tOok the concept of the folded horn Historians at Klipseh can't tell us how distonion share an inverse relationship. and transformed it into a compact speaker many KJipschorns have been made, but The greater the efficiency, the lower the designed for the music lover. Far from the Klipschorn has made its mark in distortion. Horn speakers therefore, have compact by current standard, this speaker audio history. By the early 19805, over a natural advantage over conventional brought the deep dynamic-bass and the 20,000 had shipped. Klipschorns were the cone speakers." Later at Stanford wide frequency range of the siam movie speaker of choice for Edwin Armstrong in University, Paul noted a fellow student's Iheater speakers of the 30s and 405 into promoting FM broadcasting. The claim that speakers sound better in a cor the pOSt-war living room. By using the Klipschorn was used to demonstrate ner. This was also a time of research for room's corner as an extension of the bass stereo technology as early as 1955, and horn,this speaker could be tucked out of Paul. He read, with great interest, the was used in 1958 ro demonstrate three the way while producing deep bass, and a Symposium of Auditory Perspeai"e by channel audio at the World Fair in Bell live dynamic sound that few speakers Telephone Laboratories. Brussels with the world's first center chan could rival. These experiences blended and synthe nel speaker, the KJipsch Heresy. siud into the corner horn concept. And Evcn more amazing is lhe longevity of The voice of Presidem Johllson was this much copied (and licensed) speaker. in 1939, while stationed at the proving heard at Edwards Air Force Base through No other speaker can daim to have been ground, Paul made his first sketches and a Klipschorn modified for PA use. By in continuous production for over fifty paper models of the Klipschorn. 1941 Klip"sch's bass horn design was also the Klipschorn idea had become a full years. Only a few speakers can claim to licensed to other manufacturers around have been around for even half that long. engineer's manuscript. In 1942, using the world. Sought after vinta.ge speakers Dismissed by many as an old-fashioned only hand tools in his garage, Paul con- such as the Vitavox and che Electra-Voice plywood construct, noted Patrician are twO of the only for its ability to play ben examples of this loud, the KJipschorn has licensing arrangement. developed a following and Even Leslie organs used continued interest that has a modified Klipschorn, kept it in production all chese: using a paddle wheel years. installed in the mid horn, powered by a KJipsch and Associates turntable mOtor to gel (now Klipsch Inc.) has con that organ tremolo tinued to refine the design sound. over che decades, but the cur rent KJipschorn is an obvious Evolution descendant of the first The KJipschorn has schorns produced by Paul seen many refinements anKid' his employees in a build and changes over the ing un the Army Ordnance years. The first Proving Ground outside Klipschorns were of a Hope. Arkansas. [Wo-way design and used a variety of The Man and the Speaker Stephcns, Universiry Paul KJipsch will always be and Western Electric known for developing the drivers. The first pro Klipschorn. Despite many duction run of 12 other accomplishments, con Klipschorn speakers tributions, and successful occurred in 1947. speaker designs. his first con Baldwin Organ and tribution to audio history Piano Company built outshines them all. While in the cabinets and a local Chile in 1930, Paul's interest cabinet shop built the in amateur radio and his next sevell. At this great curiosity lead him to time, the back chamber compare cone speakers and for the woofer was horn loaded speakers. The enlarged to improve iu result of these comparisons performance. VACUUM TU. I YA LLI Y I 5 SUI , 3 • K L PlCHORN I In 19<18, Klip.s<:horns were built in Ihe gain in the crowded world of firsl Klipsch rnclOry al a former [elephant used speakers. exchange building al the: Army Ordnance Proving Ground in Hope, Arkansas. This As with any p air of speakers, careful room p lacemenr is needed is currently the site of the Klipsch Museum of Audio HisTOry. In 1951, the for the best sound. With the firn three-way Klipschorn appeared, using Klipschorns, your room place the same tweeter that was used in the mem options are quite limiled, so the si and shape of the room fitmous Jcnscn lriaxial speaker, the G·610. ze h was nOI until 1952 that a final three are critical. Two 90-dcgree cor way design was developed. The two-way ners are needed to place the designs were flat to aboUI 12 kHz, hut speakers. Adequate space on with the improving quality of recorded either side of the speaker is nced ed for the walls to act as the final music, a need for extended treble was real ized and implemented. flare of the bass horn. Crowding furniture up against the speakers In 1958, driver polarittwas first will hamper the bass efficiency. If observed, and a process was implemented the corners arc [00 far apan, then to make their wiring and installation con a center speaker will be needed to sistent. In 1961, the woofer throat width fill in the centcr. A similarly was reduced from six inches to three inch voiced speaker, such as the es to boost response in the 400 Hz range, Heresy, fed a L.R signal at about and to flatten the bass response. In 1964, 3dB down, wi ll provide a. huge the radial mid-horn was replaced with an soundstage. Placing the speakers cxponenrial horn. in corners Ihat arc too close will bring the optimum lislening This resulted in a narrower dispersion position closer to the speakers pattern, but flatter frC VA CUUM T U a I VALLEY I 5 5 U I 1 3 • CORNER HORN LOUOSPEAKER SYSTEM VACUUM TUBI VALLIY ISSUI 13 K L I P 5 C • 0 R N 5 Alnire Tweeter Crossovers Y,u Network LowPass Mid Hi Pus Tweeter Hi Pass We replaced the stOck Electro Voice saureed ceramic magnet Pre-I966 Various 6dS/Octav, 6dS/Octave 6dS/Octave tw�ters with EVTW·35 tweeters. 196<> A 6dS/Octave 6dS/Octave 6dS/Octav, The original K1ipschorn tweeter, the T-35B, and the TW-35 arc all the 1971 AA odS/Octave GdS/OctaVe l8dS/Qct. ... Diodes same alnico TWeeter from EV and 1983 AK 12dB/Octave 12dB/Octa\'c l8dS/Oct. .. Trap arc a drop in replacemem for the stock ceramic tweeter. The TW-35 1 983 AK·2 12dB/Qcravc 12dBfOctave l8dS/OcL ...T rap has a slightly smaller magnd (and is 1989 AK-3 12dB/Qcrave 12dB/Ocravc l8dS/Oct. .. Trap a (ad less sensitive), These tweeters sound much sweeter and morc Tweet"J� extended than the stock ceramic tweeters. The even more robust T-350 may be used, You Designation Manufacrnrer Magnet Material but some padding will be required for itS 1951 4401 Vnivtrsiry ALNICO higher sensitivity. 1958 K-77 (T-35) Elecuo-Voice ALNICO Almeo Woofer 1980 K-77-M Electra-Voice Ceramic The stock woofer in our Klipschorn came • , w u with a cel"3micmagnet and stamped metal Note thatin the 1940s and 1950s, many units ...." .., shipp"d i,h r drivers. or with cus,omer-supplied driven.Alro, ,here "'<'remany olher drivers nOt mentioned that wereo briefly (or uniqudy) urilizcd. frame. To upgrade this driver we turned to the vima e JBL 0130A. With its four inch Mid-RAnge Drivers voice coir. , hefty alnico magnet, and cast aluminum framc, this driver provides deep- Yur Designation Manufacturer TrP' Magnet Malerial er, more dynamic bass and midbass. Other 1947 713A Western Elecuic 2-way ALNICO vintage selections include the Altec Lansing 515B or 515C. A note of caution: these 1949 P-15 STephens 2-way ALNICO efficient vintage drivers are not designed to 1951 SAHF V iversiry 3-way ALNICO handle large doses of amplifier power, so go n K-55-V easy on them if you decide to bi-amp. 1961 Ad:!S 3-W V A C U U M , U B E VA LLEY I S SUE I 3 • A C L A I S c 2 A 3 A M P L , I • Electric amps and horn speakers. They claimed that jazz music sounded "live and A Classic 2A3 Amplifier vibrant" through this setUp. In the last ten years, SE amps, fo rmerly VTV Construction Proiect an underground oddi!)', have become more visible and are appearing on the cov By John Eckland °2000 All Rights Reserved ers of even mainstream audio publica tions. There aTe literally dozens of compa Why the 2A3? cdwwards the 2A3 as their favoritc hi-fa nies world-wide producing SE amps and Audiophilc preference for triodcs over tube. Fortunately. inefficient speakers there ha\'e never been more high-quali!), [etrodes or pentodes is nothing new. Even such as the AR3 were nOt in vogue yet, so SE transformers available to audio con hack in the 19305, there were Strong opin rhe super-efficient NIce, JOL, KJipsch, SHUCtOrS and GEMs. ions about the superiority of triodes such Jensen and We stern Eltttric speakers weT<' Today, I think push-pull uiode amps are as the 2A3. 10, 45 and 50 over the 42, ideal for low-powered triode. Amplifiers set for a revival with modern day audio 6L6 and 6V6 beam mrooes, etc. Triodes like the Brook 12A3 and IOC3 used 2A3s in push-pull. In fact, the Brook 12A3 constructors and OEMs. 'When the SE amplifier was Paul KJipsch's fa vorice folks srart ex ploring different push-pull amp. There was a resurgence of illlcr circuits and designs , I think we will start est in triode amplification during 5Ceing more pp 300B, 2A3 and 45 amps the poSt-war through the mid than ever hcfore. Ifyou ask a more sea 1950s. The original Williamson soned audio enthusiast, you will find that amplifier was triode: Hiode-oon many prefer the sound of push-pull tri nected KT66s. Since very odes over just about any other design. pp few manufacturers This is because Iriodes have a sweet, actually balanced sound, deeper bass, and call be offer(d tri used with a wider variety of loudspeakers. ode ampli SE.amps, on the other hand, require ultra fiers during sensitive speakers, can have softer bass this period, response, and �re prone to higher levels many of second harmonic distonion. enthusiasts preferred 10 Builwng the Amplifier build their own In Ihe spirit of audio constructors from push-pull 2A3 amps the golden age of radio, I decided to build were preferred by audiophiles using high quality output � classic push-pull 2A3 amplifier using a for their pure and life-like sonic transformers. combin�tion of 19305 and 19405 design characteristics. Pentodes were preferred fe atures. The fr ont-cnd design of this by OEMs for their efficiency and higher Why Push-Pull� amplifier is similar 10 � 1934 Capehart power OUtput. McMurdo Silver, Philco. During the 1930s, single ended was radio amplifier, with the exception that a 6SL7GT and 6SN7GT are used instead of RCA and E. H. SCOI1 offered push-pull or considered a cheap circuil with limited push-pull parallel triode output Stages in power, and many audio enthusiasts pre type 56 triodes in the original Capehart design. The amplifier is direct-coupled some of their higher-priced radios from fe rred push-pull amps. The most popular the mid to late 19305. application for single-ended amplifiers was using only twO coupling capacitors per the output stage in low-priced mdio setS. side. Introduced by RCA in 1933, the 2A3 Tr ansformer quality in single ended (in its original single-plate version) quick amplifiers, with the exeepdon of some ly became the preferred tube in many pro-audio amplifiers like the We stern high-quality phonogmph amplifiers, even Electric 91A, was marginal at after the introduction of the beam tetrode best. There was nex, ' ... 6L6 in 1935. AmerTran, Chicago, ::.. ��... to zero _ ... Stancor, UTC, Jefferson, Thordarson and interest in other transformer companies offered high SE amps quality 2A3 transformers and push-pull until the 2A3 amp schematics and parts lists in 1960s, their catalogs. An especially elaborate when transformer-coupled 2A3 amplifier was French and the 1935 Thordarsen Tr u-Fidelity Japanese Phonograph Amplifier. Ultimately, the audio nUls 6L6 began to be used more in radio starred receivers and commercial sound applica exper! . tions. 2A3 amplifiers were reserved for mentmg early recorded music perfectionists, who with often built their own amps. anciem SJIl gle-ended During the post-war era, returning Gb Western and other audio emhusiasts again gravilat- 2A3Amplifier Power StlPply Chassis VA CUUM , U I I VALLEY I I I U I! , . .. A C L ASS c 2 A 3 A. M P L • I R BV r--r----'vWv---r-r----�Wtv_---___,r_---1501< 6SN1GT " 1/2 6SL7GT v. tMeg '" B.loD<� " " " ______ L�b:-,�===- ______��2 .630V2�F en nl'!el shown One a Self-Bias pp 2A3 Amp All resistors unless noted 2W. John Eekland Oct. ]999 6SL7 6SN7 6SN1 The phase inverter is a long-tailed pair sure where you will CUt the tube socket electronics flea market. You can also pro design. The OUtpUt stage is push-pull holes, mountings for the transformers cure almost all of the inductors in this 2A3s in self·bias mode. A separ:llle power and other components. Whatever you do, project from Hammond. Higher current supply uses a single SU4G and is very don't rush building this amplifier as you ratings on filament and B+ tfllnsformcrs conservatively rated. will wind up making mistakes, make a are OK, but avoid any lower ratings than mess of il and lose interest in the project. what is specified in the circuiT. This circuit is really quite simple and all Yo u are nOt in a race. Enjoy the process the component values are listed on the and take your time 10 do a high quality Wiring was done in the classic style two schematics provided in this article. If job. with buss-bar grounding and lots of elbow you are planning ro build this amp, my room under the chassis. Tube sockets arc: advice is to read the article, obtain all the The chassis J usedwere NOS vintage vintage ceramics, but the new Chinese necessary pans and chassis, and Clrefully aluminum BUD rypes that I painted ceramic sockets will work fine. l original plan the layout of your amp. In order to wrinkle black. One chassis is for the ly tried 1950$ vintage Sprague Black cut holes in the chassis for the tube sock power supply and the other is for the Beauty .22uf@600V coupling capacitors, ets, you will need 10 borrow or purchase a amplifier. If you can't find any old chas hut they sounded a little rolled off. I 118 inch Greenlee or equivalent circular sis, Hammond Corporation has several Finally, I installed .22uf@ GOOV Illinois chassis punch. All other 100ls needed reasonably-priced chassis sizes available in Capacitor ICMWR metallized polyester should be in your tool kit or Cln be pur either aluminum or steel. Power trnns caps. These took a while to break in, but chased fr om an declronics parts retailer. formers, filament transformers and chokes worked fi ne. For resistors, I used the old Bc sure to carefully measure and re-mea- are items from my parts box or the local rdiable AJlen-Brndley twO wan carbon comps. The A-Ss have a smoother, more relaxed sound when compared to some of the new me(al film rypes. The power supply was built on a sepa rate chassis and connected ro the amp chassis via an umbilical cord and Jones plugs. Howe\'er, if you can't findJones [ plugs and socketS, you can hard-wire the power supply ro the amp chassis. I used a fY,'o-chassis design to keep the sile and weight of (he chassis down and ro improve longevity of components. The supply design has twO pi networks and employs tri ple capacitance filtering using surplus oil-filled can-rype capacirors. With triode amplifiers, oil capacitors give that deep. effortless and liquid sound characteristic. VACUUM TUBI VALLIY S 5 U E 1 3 • " 0.5/\ 2.5VAC 10 2.3. Self-Bias pp 2A3 Amp (lilt clllnnll) John Eckland Oct. 1999 0.5. Pow�r Supply SrhmMtk If you cannot find oil-filled power supply well-made transformer, perfectly suited fic:nion of the 6SN7GT. You can also try caps in the specified values, YOII can use for this application. In this amplifier, the reducing the resistance valul': of the plate either film and ro il or high-qualiry el<':C 5-542 transformers were run in self resistor in the first triode stage for higher trolyties and bridge rhem with a smaller biased mode for simpliciry and sonies. In plate voltage. This will give you more value tubular oil capacitor, like a .47uf@ self-bias, it is important 10 find 2A3s that gain if you decide to use a 6SN7 for the 600V. There is also a dual filamem sup are fairly closely matched (within 10% in first stage tube. ply, onc for each channel of the amplifil':r. gm).Measured OUlput power is aboUl This is important, to allow output stages eight watts RMS per side that should be We tried the amplifier with vintage JBL to operate independently. sufficient for a lot of speakers. HartSfidds, 1980's vintage Klipschorns, B & W OM-I lOs, Von Schweikert 4.0s and Since older, vintage UTC and Peerless How Does it Sound? 1980's Klipsch Chorus Is. The amp has a output transformers are getting hard IQ sweet and balanced sound with adequate After about 40 hours of break-in, the find, we contacted Mike LaFevre of bass. Sonies arc different than an SE 2A3 amp really started to smooth out. The Magnequest Tr ansformers in Philadelphia, amp, but are JUS! as desirable. With eight Peerless/Magnequest output transformers Pennsylvania (www.magneqUCSt.com). watts of power, you can drive a lot more really be!r-ln to perform well the longer Mike purchased the original Peerless speakers than with JUSt twO to three we used the amp. I used either NOS transformer name with thl':ir transformer warts. The amp has a smooth, easy-to-lis Sylvlmia or RCA bi-plate 2A3s. 19405 designs several years ago and is in the ten-IO sound that you can enjoy all day RCA�black plate" 2A3s were the most �rocess of reintroducing several of thl': long with no listener fatigue. As with any musical. Ifyou have a lot of money, the classic� Peerless OUtput transformers. DIY project, sonic performance will vary single-plate 2A3 would probably be the After consulting with Mike, he suggested with the skill of the builder, the qualiry of best-sounding. The new Sovtek mono we try his reissue of the Peerless 5-542 the components used, and the abiJiry of plate 2A3s are also an excdll':nt choicl': for that was initially introduced back in the builder 10 �tune� the amp for best this amplifier. RCA and Sylvania 1950. performance in the system. 6SN7GTs and 6SL7GTs from the 19405 The new 5-542 ($149 each) is made seem to have beUl':r imaging and are more John Eck/and is a lub( audio sp uia/iS( with M-6 grain-oriented silicon-steel lam musical than 1960 through 1986 vintage miding in Paw Alto, Ca lifornia (65 0)- inations and has a 5Kohm primary with a Consuml':r JANor bonks. 323- 0/01. H( rrpairr and rmom dassi( maximum power rating or 40 warts. radiol, juluboxts, and "intag( hi-fi (quip As with any tube amp circuit, modifiCll Howc-ver, Mike said he would probably mtnt. Ht built his fim rub( amp using tions and potl':ntial impro\,l':ments can be rate it at about 25 to 30 wam for best 684 triot/a in 1966whin ht was in tht made. I tried using a 6SN7GT in place results. The Peerless 5-542 has a current �ighth gratk. Sinu thm, John has built of the 6SL7GT in the first nage and r:ning of 140 mA per side (14 mA unbal UlJtra/ singk-tntkd andpush-pull amp/i noted thl': sound to be noticeably anced) and a frequency response of 20 to fim wing Ws, 3008s, 6I6s and 21 Is. smoother. Howc-ver, power output was 30kHz + or - one dB. It appeared IQ be a definitely reduced due to the lower ampli- VACUUM T U 8 I VA LLEY I S S U • , 3 .. 'ROBLIM CONIUM •• ILleTRON c s sumers to buy new toys as frequently as Problems with Modern possible. So, rarely are such products sup ported more than five years after their introduction. Sorry, parts and service data Consumer Electronics no longer available. Compare this to a rypical tube amplifi By Eric Barbour CXlOOAll Rights Reserved er. Not only is it easy to repair, the pans to fix it will always be avail able (at least in We live in strange times for consumer incapable of handling more than 25 watts some kind of substitution form). Tu bes R..\4S audio electronics. The world is filled with of power. The crossover usually con and OUtput transformers arc still being ever- incrcasing moumains of black plastic SiSlS entirely of a single cheap electrolytic made, unlike many integrated circuits of dectronic mulc h, all made in Niian coun capaci(Or in series with the tiny 50-cent the last 20 years. If a tube goes bad, the uiC5 by the daughters of impoverished rice rweeter. Thc sound is uniform among all user can JUSt pop in a replacement. And if furmers, for wages that would be consid such products: tizzy, harsh. metallic, with such an amplifier finally gives up the ered slavery in Europe or North America. massive bass distOrtion and non-existent ghost, it is worth dismantling for recy Yet consumers, especially Americans, grow stereo imaginj' This is the norm at the cling, because it will contain very little ever fo nder and more addicted to this end of the rni lcnnium, and this is what ABS or polystyrene plastic. Tubes tend (0 cheap and disposable dec[fonic trash. an entire generarlon (and soon, ewo gen force good construction techniques, erations) of Americans have grown up lis requiring lots of recyclable iron, copper Flat Black Racks tening to. It is all they have ever known of and aluminum. Go into any consumer electronics "high fideliry." Digital Deception emporium, and you are confronted with Politically Incorrect Electronics rows of ugly "mini-rack� systems. The Even more controversial is the current current incarnation usually features garish Once these black boxes break (and they push toward digital in the professional color vacuum-fluorescent displays, flash do break, in spire of [he "infinite lifctime� recording studio, especially this fad for ing in time with the music (and serving of semiconductors), they end up dum ed p "los$)' compression� di gital audio systems. no useful purpose whatsoever, except [0 in landfills, leaching toxic heavy metals Fools with magaz.ine columns are current make the weak -minded think they are get and plastic residues into water supplies. ly spreading corporate propaganda that ting a quality audio product). The ten Because they are made as cheaply as possi MP3 sounds as good as COs and will (0 dency [0 make these vile things look like ble, they are not designed be easily dis transform the music industry. They claim carroon robotS has become overwhelming; mantled for recycling. Indeed, a move is that MP3 will wipe out all older recording afoot to use you arc hard-pressed [0 find one that in Europe outlaw the of lead fo rmatS by allowing consumers (0 down � looks �rcstrained. � The Megarroid Of in electronic solder, and to fo rce manufac load music from web sites at \'ery tow to Doom� appearance, which appeals 10 [he turers make electronics 50 they are easi COSt, and with little or no advertising or 14-year-old male mind, is universal. ly disassembled for recycling. Nor would promotion. Most of this blathering is seen [his matter much--the manufacturers are in computer magazines and in Internet- Wc've been told that these gadgets are huge corporations, eager to force con- usually designed by the junior members of manufacturer's design teams, and always to a specific price point. Rarely does a higher price equate to better sound. More likely, a costly rack system will simply have more semi-useless programming fea tures and more bUlTons than the botwm line model. The circuits arc universally based on horribly sleazy ten-cent op amps, such as the venerable 1458, and on power amplifiers based around ICs which COSt len than $2 apiece in OEM quanti ties. Their circuitS are direct steals fr om 1968 designs, and they depend on 1001- dB of negative fe edback to obtain tOlera· ble distortion figures, low hum and low noise (since: their power supplies are usu [ ally inadequately filtered). Most won't even drive fo ur ohm speaker loads! Bad as the electronics in modern audio gear might be, the speakers included in these all-in-one packagC5 are made even more cheaply. We have literally seen �S(ereo systelll� speakers whose cabinets JryJack El/iano were partly made of corrugated cardboard. ��c;;;;OO" The drivers commonly have abominable frequency respollse, are assembled on This is what we know softr. He 's a solid statt stereo equipment salesman, paper-thin stamped metal baskets. and are and it appears he was shot with a 45/ VACUUM TUB I VALLIV I 5 5 U I , 3 PROBLIM CO NIUMIR ILICTRONICI related business publications. Yet we have archival stonlge today is non-mag optical. fa vorite muscle-bound action S(ar. scen many respected exp<'Wi in the profes A tiny ding in a (digiral) disk can mean sional recording field who are VERY dis you spend the next day calling all the Lynn OI50n, currently editor ofV&T gruntled with this state of affairs. original musicians back in, and the day News and a former designer of �urround aher that, consulting with your lawyers." electronics, says in V&l"s August 1999 For e xample, John Sabatc:llo, a well issue: "One of the most disappointing known recording engineer in Hollywood, S[. Croix claims that OAT digital rnpe things about contemporary surround h2S actually done listening comparisons of machines, always Asian-made and widely sound is the palXr-thin image--it wraps MP3 versus high-rate PCM audio, and he used by pro and semi-pro T«ordisu, ha\·e around you all right, but the effect is like bluntly states ''It's JUSt a marketing ploy- similar problems, especially when data being surrounded by posters hung on a most consumers don't care. It's great for dropoutS occur: "OAT machines recon clothesline. The low-b·c:l reflections are kids, but it's nOt a quality format.� StrUCt your music using interpolation scrambled by digital compression or Sabatello has similar fe elings about Sony (they take a guess), without notifYing aSSOrted solid-state gremlins (Class AB, Mini-Disks, which use a compression you, whenever they feel the n�d. And s!ewing, or momentary loss of phase mar scheme comparable 10 MP3. He even why do we care? Bedluse they f�1 the gi n), the depth and you-arc-there realism finds the current industry standard for need quite ohen!" Engineer Omo is sucked OUt of the recording, and no conventional PCM audio, 16 bits at 44.1 Wilburn made these comments: "The amount of synthetic signal processing can kHz, 10 be inadequate. �["m not anti-digi analog (tape) has always been far superior restore it. � Olson even shows a diagram tal, but they will have 10 improve the to the OAT. My Nakam ichi 1000 cassette for an all-vacuum-tube surround decoder sample rate. M deck sounds far superior to me OAT. It in this article. would bring such joy to my hean, 10 take Stephen St. Croix, the well-known the OAT machine into the parking lot, Bogus Broadcasting columnist for MIX magazine, made simi and take a sledgehammer 10 it." As for radio broadc2Sting, large corpo lar commentS in his January 1999 col rations now own most of the radio sta umn. "Lossy data compression is, in my Home Theater Hypnosis tions in the United States, thanks to the opinion, not great at all and should not Currently, high-end audio is losing current FCC tolerance of monopolistic be used. Take ten seconds of music, shove some ground in m ia reponing to the behavior. These firms have dicrared the it through your fave lossy di gital dat;! ed mania re igion "home theaU'r.M progra mming fo rmats, so that the same reduction unit, save the result and repat dll l called Com anies have popp d up all over th tunes are played over and over, usually the cycle several times. That'l! teach ya. e e wor1 :r., who (for a very large f�) will turn �oldies.� It's a safe, cl sed system, arrived Co ies of copies using dat'.t reduction are � . p an extra room in your house into minia at over many years to Insure consIstent ga rbage.� He even finds conventional dig a ture video cinema, complete with uncom advertising profits. irnl recording to have major disadvanrnges fo rtable fo lding seats and a popcorn compared 10 analog formats, especially fo r machine. The mandatory audio equip. The eurr<:1It frantic push for digital TV archival storage: "The only truly safe ment for this ki nd and digital radio broadcasting is even r------, of setup is always more specious. Consumers do not sec the the modern "sur- justification for paying $5000 for a digital d TV set, while the broadcasters and cable 'I' : : U Itra - .one C aps �� ��g : �:: TVsystems frantically try to assemble Laser·Etched Silver Foil in Kraft Paper and Oil encoded source digital sysrems, 2S mandated by [he FCe. We understand that less than 50,000 digi- Amplifier and Crossover Capacitors similar to the old \ tal TVs have been sold in the United " SQ and QS The //Jost lift like capacitors / ht/VI! ever hmrd!" quadraphonic sys States, versus a current estimated analog. . "Mu sk stepsforward from tlu rpmkers. Exulknrpacing IInd rbythm. " tems, or else a TV population of 200+ mi llion A similar situation obrains for digital radio--the Perfect for Single·Ended Triode Amplifiers and Horn Speakers lossy digital com pression scheme. digital data format has not even b�n The decoders and fully decided yet. Yet the FCC mandate - power amps (and the bizarre ra\'ings of a few industry invariably arc pundits about the glory and inevitability designed to a price of digital broa.dcasting) continues to press point and accord tOward all�digital TVin 2006, fo llowed ing to suict tech· by the requirement that the stations turn nial standards their old analog frequencies back 10 the which have little FCC for auction to the highest bidder. rc:lationship to (Major reasons for all this: the Clinton 6S0V Silver Coupling Caps NEW 300V Crossover Capsl actual human adminisuation has apparently claimed to have balanced the federal budget, primari O.Olul $13.20 eo Solid Silver Leadoutsl hearing response. M2Ssive sub ly by assuming the auctioning of valuable 0.02ul $15.40 ea 1 uf@200V $45 eo woofers are VHF and UHF ·IV channels in the 0.05ul $17.60 eo 2uf@200V $70 ea mandatory, the future.) Of course, manufaCturers would 3uf@3OOV eo 0.1 ul $20.90 ea $95 better to pound be so happy if all consumers were fo rced 0.22ul $30.80 eo 5uf@3OOV $135 eo the listener into to buy new TV sets and radios. Our advice: keep your analog TV set a.nd ana 0.47ul $44.00 ea 10uf@3OOV $175 eo unconsciousness with explosions, log FM tUner. The changeover won't be l.0.1 $70.00 ea VTV Pro-Tube Shop gunsho(S and loud on time, ifit ever happens at all! 2.0.1 $100.00 eo P.D. Box 1499, lakeport, CA 95453 USA grunts from your (707) 263-5881 • (707) 263·7648 FAX VACU UM 1 U B E VA LLIY I I 5 U I 1 3 • S COT, 2 2 2 & L K 4 8 A M P L F • • 5 One of(he unique features, of the 222 Scoll 222 & LK48 Amps and of other Scart integrated amps, was the third or middle: channel. This extra OUtpUt was used in conjunction with an Sweet Sound for a Song auxiliary amplifier for fuller sound, wider soundstage, la,k of "hole in the middle" By Charles Kittleson 1:2000 All Rights Reserved effect when speakers were: further apan. It can also be used as an output for a mono With rhe mass marketing of stereo used push-pull EL84/6BQ5s in the OUt- amplifier extension speaker output. All records in the late 1950s, most hi-fi put stage that produced 12 watts RMS Scatt amplifiers incorponucd a low rre- qucncy rolloff that became operational equipment manufacturers struggled to get per channd with 0.8% distortion at rated COSt-effective Stereo equipment to con output. The EL84s were in self-biased below 20 cycles. This circuit was sumers. Many music enthusiasts were Scatt222 8 Front pane'::l' = designed ro prevenr overload of the out- reluctant to change to stereo and decided = :::=::::::::::=:::::;:::; to stay with mono fo r the time being. ======;:::: From the mid-fifties, mid-fi companies ���1 like £ICO, Fisher, Harman-Kardon, Heathkit, Knight, Pilot, Scott, Sherwood and Suomberg-Carlson were producing audio equipment for the low to middle end of the market. As a result, rheir chal lenge was to produce a competitively priced stereo illtegrated amplifier to get the most unit sales. In the early part of 1958, H. H. Scott operation with 360 volts on the plates in put stage and speaker from subsonic rum introduced a series of stereo integrated conventional pentode mode with the ble frequencies, from accidental dropping of die tone arm, or from record irregulari. amplifiers that would impact the world of screens running at full plate potential. hi-fi stereo for some time. Their first Front-end tubes consisted of four ties. Stereo integrated amplifier was the 299 ECCS3/12AX7s with their filaments ($199.95), a 40 Wom tube stereo amplifier string-wired in series. Voltage fo r the Scott 2228 using 7189 output tubes. (Note: The front-end tube filaments was derived from For the 1959 model year, Scotr intro model 299 Scort amplifier is described in the 60 volt cathode potential of the out duced the 222B in December of \958. more detail in vrvissue #12 pages 19- put tubes. The driver/phase invener The tube complement was the same, but 23). ror the budget-minded music listen tubes were ECFSO/6BLBs and the rectifier power was increased slightly to 13 waftS er, Scon inuoduced the model 222 was a GZ34/5AR4. No adjustable bias or RMS per channel with harmonic distor (S 139.95) a few weeks later. These twO DC balance controls were included on the tion of 0.8% at rated output. amplifiers became very popular and were 222; only AC balance adjustment pots highly rated by audio and consumer mag were on board. The faceplate was changed slightly with azines of that era. a tape monitor slide switch that was Other features included [WO low-level added in the center of the panel. The out We will examine the development of inputs and twO high-level inputs from put transformers had a slightly larger stack the Scon 222 amplifier series and the stereo sources. There were also stereo OUt and were labelcd TRA-7-1. Interestingly, related LK-48 kit amplifiers in this article. puts for a tape recorder and provisions for the OUtpUt transformers had an £lA code These amplifiers represent an imponant Sc of 100, indicating that they were either ott 222 Front P'mei made in-house, or by a vendor Scon did nOI warn their competitors to know about. The power transformer was labeled TR-12-7 and appeared to be simi lar to the original 222. The EL84 screen • i grids were no longer tied to rhe plate sup - . ply and were decoupled with an addition • "c al filter capacitor with a slightly lower - . •. . •.. . voltage potential. .:. -; :� .' Scott 222C For the 1962 product year, Scort 4, 8, and 16 ohm OUtput for both speak launched the 222C, rated at 20 wans part of hi-fi histOry and are a bargain for ers. The front panel was aluminum RMS at 1000 Hr. At typical listening those who want sweet sound for a song! anodi7-cd in a �champagne gold� finish levels of one to twO watts, total harmonic with polished brown Bakclite knobs and disrortion was sai d to be in the range of Scott 222 gold colored edges. Front panel controls 0.05%. Improvements included huge The 222 was a complete two-channel included volume, balance, dual bass, dual output transformers (TRA-B-5-1) that stereo integrated control center consisting treble, function, source, loudness, tape were sourced fro m Stancor (EIA code of twO complete amplifiers on a single moniror and high filter. 352). The larger transformers were more chassis with a shared power supply. It than twice the size of any comparable VACUUM TU. E VALLEY I 5 5 U E , 3 s co, T 222 & L K 4 • A M P L • ••5 Scon 2220 2220, including better bias adjustment For its 1963 line, $CO([ facilities. There were variable controls for DC hired an outside design eacl1 <:hannel's bias and balan<:e, a pair firm to Msprucc up" their of bias test point ja<:ks and a bias adjust integrated amplifiers. As ment switch for improved fine-tuning of a result, a new faceplal!:. the amp. control knobs and chassis LK-48 layout wcre incorporated. The: faceplatc was cast SCOtt launched the LK-48 Scon Kit in aluminum with polished 1961 for the growing hi-fi kit market. edges and an aluminum Peak power rating for Clch channel was 24 control pand which now wattS at 1000 Hz and 20 wattS continuous, included a headphone slightly higher than the 222C. jack. Knobs were casl Apparendy, Scot! spent a lot of money plastic with glue-on metal developing itS kitS and the profit margin was 100ver �::::�"��"t-t- ,,<:J�_J caps. Six slide switches than wi th eompar.l.ble assembled � �=::��������:::�� were installed on the [OP units. The ki t assembly manuals were Il�� orlhe front panel for excellent, with complete instructions, lotS iEL84/7J89 amps and wcre boasted about phono equalization, tape monitor, scratch of drawings and multi-color wirin charts. in Scon advertising. Another change was g 10 filter, speaker on-off, power on-offand Everything came packaged in a well some: higher rated 7189 OutpUt tubes, ]ouclnm. The:output transformers were the: thought-QUt container that included all the operated in fixed bias mode: with only a the: 222C ecessa 0 same: type as bur relocated fur- n ry partS. pair 0f DC ba I ance pOtS r was The result a more powerful amplifier • with better bassresponse that oould be used wi th less effkielll speakers. Published Soon specs indir,;ated that the 222C power SCOtl 222 C Fro"t Pnllel ba.nd was 19 to 25,000 Hz ... or - 1 dB. fe rences: I. A dark brown faceplate was Fccdba<:k-rype tone oontrols were quite better velllilation and cooling. The 6BL8f6U8 Standard with a cl1ampagne gold faceplate effective a treble boost and <:Ut of ... or driver/phase inverter tubes were with 2. All \vere - as an option, the slide switches 15dB at 10kHz and bass boosr and an of mounted ncar the front of the chassis. - on the cop half of the chassis and the con ... or 15dB at 50 Hz. Minor circuit changes were made to the trol knobs were located on the bottom of the chassis with the bass and treble controls in a concentric configuration. There were some relatively minor circuit changes as well. Both the power and the Output trans fo rmers a pcar to be the same types as the :r 222C an 222D. $<:Olt kits were very popular, in cluding. the LK-48, the matching LT- I 0 mono FM tuner kit and later the 1.1"-110 stereo FM tuner kit. Tens of thousands of these units were sold to do-it-yourself audio enthusi asts of the day. LK-48s are still around and have been passed on from father to son. lotS of good tunes have been played through these amps, and with proper restoration and service, many more can be played. LK-48B 1963 1965, -I'l- - From through about Scot! - � -- sold the LK-48B, which was a kit version of me ScOtt 2220 with the updated cos Scott 222C Cb nJSis metics, different chassis layout and other VA CUUM TUB E VALLEY J 5 5 U E 1 3 ... 5 CO,, 222 & L K 4 8 A M P L , I R 5 minor differences. The output and power transformers were similar to the Scon 222C parts. '" (: 0 •1" T ... . "" .... - .. . • 200, 200B and LK-30 • In 1962, for beginning and budgeT audiophiles, Soott made the model 200 stereo integrated amplifier which produced 6 about 10 wans pe:r cbannel. Priced at ., about $139, the 200 offered many of the fe amres of the: more: expensive SCOtt inte Scort222D Front Pa1lfd grated amplifiers. The faceplate was the fa miliar champagne gold with the gold ringed plastic knobs. However, it did not have a stereo balance control. Tu bes in 1 the 200 included three ECC83/12AX7s for the phono, rone and first audio cir cuits, fo ur ECL82/GBM8s (a combination ' .. .. 9-pin pentode driven by a small hi-mu ni �; - = -==w-"' - - .0 ode, similar to 112 of a 5751) and a 5AR4 rectifier. A kit version of the 200 was the LK-30, also introduced in 1962. The 200B model was introduced in 1963 and Scott LK-48 Front Pa nel made through 1965 or 1966. It was basi cany the same as the: 200 except for cos EL84s. Now, wi th many new enthusiasts For reliable operation and best sound, metic changes and minor circuit upgrades. becoming interested in tube audio and your Scort 222 should be electrically 75915 costing more than complete ampli restored. All of the white tubular ceramic Production Estimates and Va lues fiers, there is renewed interest in the EL84 American Radionics capacitors should be and SCOtt 222 series amps. You can expect replaced with a good quality, modern film Daniel von Rccklinghausen, VP of engi to pay anywhere from $10 (at a garage capacitor. Any under-chassis axial elec neering for H. H. SCOrt, estimated that sale) for a rough 222 to 5400-500 for an trolytics should be replaced with new, 60,000+ units of all versions of 2005, 222s excellent, fully rebuilt and res[Ored 222C modern electTolytics. Above-chassis can and LK-30s and LK-48s were produced type multi-section elecrrolytics should be from 1958 through 1965. The 222Cs and Restoring a Scort 222 checked for leakage and if possible, be re LK-48 are: the most common and seem to formed slowly using a regulated, variable be easiest ro find. The scarcer models Never power-up a vintage amp without DC power supply. If capacitor cans can seem to be the first version 222s, 22205, inspecting and testing ie. It is important not be re-formed so leakage current is LK-48Bs and LK-30s. [0 obtain a schematic diagram to deter mine component values, correct wiring 5mA or less at rated voltage, they should As with every collectible, condition is and voltage points. Begin with inspection be replaced. everything. Finding a 222 or LK-48 in of the: unit for any missing parts, shorts, The flat Siemens selenium bridge rectifi mint condition is becoming less common burn marks, burnt smell, etc. Repair as er should be replaced with a modern sili these days. With internet auction sites needed or have your technician do the con bridge rectifier. In addition, plate like ebay and others, more people have work. The tubes should be removed and resistors in the phono section can be more exposure and access ro collectible tested. Most SCOtt amplifiers have a tube changed to modern low-noise carbon film tube audio equipment than ever before. location sticker on the bottom plate. or metal oxide film for quieTer operation. Unfortunately, prices tend ro rise with Tube sockets should be re-tensioned with The small screw speaker terminals can be demand. For many years, audio collectors a dentist's pick and then cleaned and pro replaced by modern Cardas gold or copper couldn't care less about anything that used tected with Deoxit R-5 spray. R-5 should speaker terminals that fit in the rectangu also be used ro rS;;;;�UQ.:g��:::::======------l lar hole. If time and care are taken in the clean and condi- restoration process, your Scon 222 will be tion slide switch a reliable performer for years to come. es and volume controls. The What Do They Sound Like! chassis should he dusted or wiped EL84s/GBQ5s have become the tube of clean with a soft choice for many enthusiasts, because of eloth. Since their sweet sound, quick dynamics and Scon chassis are surprisingly musical presentation. For aluminum and more detailed information on the are typically not EL84/6BQ5 tubes, see VTV issue #8 lettered, they pages 3 through 7. The Scon 222 is can be polished musical, sweet, and lively sounding, prob for a mirror-like ably due to smaller OUtput transformers finish using that have a quicker sound. Overall per Simichrome formance is balanced, but they can be metal polish. bass-shy with inefficient speakers. The VACUUM , UBI VALLIY I 5 $ U I I 3 • 5 COTT ••• & L K ... A M P L , I R • New H.H. Seott Stereo Amplifier has features never before offered at $139.95* 222B is similar sounding (0 the 222, but has slighdy morc power and a little better The new H.H. SCott 24 watt stereophonic amplifier, Model 222, bass response. The 222C has deeper bass response, but the mids and highs do not seem as lively as the earlier models. Some features never before available for less than $200. fed that (he larger rr;lnsformers h:.l.ve a H.H. bass C'ffiphasis :u ,he expense of the mids. Scon's fine reputation. Chetk the features Model 200s and LK�30s arc also sweet see why you should build yo ur new stereo sounding, but have limited power and arc not very punchy. H.H. Seott Model 222. Generally speaking, Scote integrated ,m:rliflcrs tended to have bener midrange an in-the-room presence when compared [0 similar eype Fisher integrated am pli fiers. SomeenthusiastS think that Fisher integrated amplifiers can sound more recessive due to Fisher's use: of a volrage doubler for B+ voltage with a solid-state bridge rectifier. By comparison, the Scon 222 and 299 series used a tu� rectifier without a voltage doubler. Note, howev er, that Fisher did use a tube rectifier on ils earlier X-lOO, X- IOI and X-202 inte grated amplifiers and these models can -- sound excellent. $tool.1__ _ ...... -...... _of_ ",�,.:;",,,,J.... ._I d ,.. '..... 011 �•• I .. ..• 001,,,, ... ,,;_ -,.-_.. Since SCOlt 222s produce al leasl 10 .. ,-_ ...... 11' ...... o. . , , .. ,1.01 "' _ .100_ .. · watts RMS, they can be used with any hi .... ' ,�. thing from a Klipschorn 10 a Bouk B- TW. ,.tioo hili !'CO 1 .. 1.,1" ... 1" . ....,. -. __ "11,.. 4000 or most modern bookshelf speakers ...... ,. ... ,...._1. ..· ...... !loo. ,.. _ lOt J'-' wi th 91dB/onc watt/meter efficiency. _ .. ... 1IrIrirtc ,.."-- 'I.,,, •., .. "'...... hn. Some contemporary bookshelf speakers to -� _* 1IoJ.. 1IpI. -�... consider would be Cdestion A·Is, Paradigm Titans, and NHT Super Oncs. 1._ : U!I. .., _!'l���� 1�.=:.�-:.• �i1,�: �:: 1> ..... 10. '.11. _ ( _ .:ldbJ : De _.,':} ....., ' mi"" ,," It,,: 10,01l!O' ;;:::��. �'!:::c�:� to':" ,:::.�� ::.�::.-= References: ...... __ _1U'.�· I. Audio Magazine, 5cotl 299 and 222 N.lI. seoTT INt. o..t. A.:t,m_.... _.II.o�_ I.q.ott:T_l_eo.,.lIW._SI. "-l.t. Amp/ptr R�uitw and Tm , November ''''I.. ... __.!!:..!!:. s...tr-. 1959...... ·w... ., Rod'" " u.u. A__ • _...n.. 2. H. H. Scon Company, catalogs, - £0.� ...... , schematics and service manuals from 1959 through 1965. SEND NOW FOR RouIi.. (l)IIIIplde ddaiLt MI ,....,""'MatW tU "lid ,...., _pld. JUg GMidcHi Fi C 1959 Seott Advertisement VA CUUM , UBI VA LLIY I S 5 U E I 3 • ID U N C L I • A M • MONSTIR constructed map that made up each air Computing with Tubes sector. All of the coding was in assembly language. ril e Savage Art All this drove 50 CRT realrime monitors, each having a light pen like the onc By Eric Barbour c2000 AI! Rights Reserved atrached 1"0 Whirlwind, used by the inter cept technician to specify a target for 6. Uncle Sam's Monst.r tracking and interception. Each SAGE could track up to 400 aircraft at a time. During the conS(fuccion of Whirlwind MIT's Digital Computer Laboratory had These displays took onc second to update. (the first reahime computer - sce vrv been taken over by the Ai r Foree, becom using very long-persistence phosphor to issue #11, p. 20), {Wo major turning ing the core of MIT's new research cemer, allow reading the slowly-repainted screens poims occurred. First, rhe Soviets exploded Lincoln Laboratory. of data. Each main core module w:u 69k their own nuclear bomb in 1949. Second, words in size, while the common drum the V.S. Army conducted a test of their The team developed a new machine memory held 150k byres. Each SAGE was civilian Ground Observer Corps. This all called Whirlwind 11. It acted as the proTO housed, along with itsown independent 1- volunteer group had the responsibility of type for the final system. Twe nty-three "air megawatt diesel power plant, in an ugly filling in for early coas�1 radar systems by defcnse secTOrs� were created, and each one windowless concrete blockhouse four Sto watching for invading aircraft. was to gCt a Direction Center cOlI(aining a ries high. Unfortunately, the Corps proved to be dual-redundant version of Whirlwind H. This was SAGE--SemiAutomatic Ground completcly unreliable--Cold War jitters The firs! operational system went into Environment (the presence of Nat Sage on and Communist �witch hums" had so service July 1958, at McGuire AFB in the senior staff may have influenced the inflamcd rhe public that the Corps volun New Jersey. Eventually, 26 systems were name selection). It was the first digiral teers kept seeing Soviet bombers behind built, adding up to 56 CPUs (including computer to receive an official US defense every cloud. fo ur systems for software development). procurement designation, AN/FSQ-7. (Side note: it's ironic that the anti Thousands of false alarms were turned IBM was selected as the primary contrac Communist panic that starred this huge in. (Ar the time, the USSR didn't even tor, and the company benefited greatly project had run its course by the time the have a bombco;r capable of reaching the from the technologies it got from SAGE. system went into operation, 8 years later.) By 1955, IBM had the first The SAGEs provcd to be extraordinarily prototype wotking in reliable. A dowlI(ime average of less than Poughkeepsie, NY. It was a 10 hours per year was typical, for a record 32-bit parallel-bus processor, ofbetrer than 99.9%. Those who claim with the CPU and core mem tube computcrs were unreliable can mull ory duplicated, while the liD over that statistic for a while! systems and drum memories were common to both CPUs. In spite of rapidly advancing computer Switch over could be accom technology, most SAGEs were nOt taken plished almost insrantly. Data omine until 1972-76. The final SAGE in came in on very slow data operation in the US apparently w:u at links from complex radar Luke AFB in Ariwna, believed to be shut installations via landlines and down in 1977. The only one not in the HF radio channels. Each USA, at North Bay, Dmario, finally was United Statcs.) The result was political tur channel was dual-redundant, with auTO dismall(led in 1982. To gether, the SAGE moil, and Congressional demands for a matic failure switching, and all were made installations constituted the physically reliable air-defense system. of vacuum tuhes. (Some transistori1-td largest, most complex computer system the equipment was introduced late in the pro world has ever seen. The Air Force, gi ven responsibility for ject. Even so, most of the SAGE installa devcloping an ai rcraft tracking SYStem, rions were 80% tube until they were final References: resisted. ar first. Ir knew what a m:assi\'e ly shut down more than 15 years later.) 1. Project Whirlwind: The History of A expenditure of money this would require Pioneer Computer, Kell( C. Redmond and rhat whole new technologies would be Indeed, each SAGE main computer con and Thomas M. Smith, Digital Equipment needed. Still, in Dctobco;r 1950, the Air tained 55,000 tubes in seventy rows of Corp. Press, 1980. Oefense System Engineering Committee racked modules. Tu bes used included the 7AK7, developed for Whirlwind, plus a recommended development of a comput 2. Bit by Bit: An ustratedIll History of mishmash of "super-premium� rypes, with erized air-defense system. It went to MIT Compurers, Stan Auganen, Ticknor & ocral, lokral and miniature basing. Lots of for the knowhow, and some of the Fields, New York, 1984. Whirlwind team (minus Forrester, who 6888 and 6889 pentodes, plus germanium went on to academic work) came on diodes, were used for logic, and the core Many thankr to th� $faff th� Computtr board. memory drivers were 6080 or 7236 dual Musrom History UnttT r th�jr assistanff power triodes. 5692s were used as the flip t 10 wilh rtttarrh. Also for a wing us tIIlt� A test of Whirlwind on April 20, \951, flops in the main system regiSlers. photos of th�ir SAGE�qui pmmt. And was a success--the computer was able to Apparently, SAGE may have been the thanks to Us alTlust, Paul Edwards aM track twO ai tcraft accurately enough to largest consumer of 56925. Each accumu Jam�s Wo ngforgi ving rht SAGE historical allow a ground operator to direct one air lator contained a �split" 32-bit numbco;r, to 1«tuTt in 1998 which mlld� this possibk. craft to imercept the other. By this time, serve as X and Y coordinates in the radar- VA CUUM TU •• VALLEY I 5 5 U I I 3 A • USA K 2 0 0 3 A M P L F • R the sound, adding more detail and a large:r ASUSA K2003 Amplifier soundsnge. Most of the bass bloom was remo,'ed as welL Next, we tried NOS Siemens (West German) E84Ls (similar to Good Th ings Come in Small Boxes 71895) and aJAN Philips 12AX7WA in place of the So\'(ek tubes. These: rubes By Davld Barde. "2000All Rights Reserved provided the 1<2003 wi th the $wttt and delailed sound associa[ed with much more The KlOO3 is a small. ina:pensi\'c amp chassis, making it easier to assemble.) ex�nsi\'e amplifiers. With these changes, from ASUSA's line of tube amplifier kits. Assembling the kit doesn't take long. as the K2003 is JUSt shy of me sonic magic This rime Antique Sound USA engine.:"rs there are only a handful of parts. We associated. with SE 2A3 and 300B triode chose the EL84/6BQ5 pentode: as the out assembled our kit in about five hours. amplifiers. But don'l discoum the Sovtek put tube for single-ended operation. By EL84s. While they didn't have: the detail Wc were quite surprised at the sound of using only a pair of E.LMs and a single and tranSparency of the Sie:mens NOS this litde amp. This amp doesn't sound ECC831I 2AX7 on a small chassis, ASUSA tubes, they did have more gain. A great could offer this am kit at a very small at all! Bass is quite solid, although it NOS p combination is your F.avorite 12AX7 modest does have JUSt a bit of $399. While many with the Sovtek output tubes. This is a bloom. The highs low wattage SE simple and modestly-priced upgrade that n amps look are u congeSted l anyone can do. like 800- and the derai is No, pound good. it ASUSA's 1<2003 is quite a bargain at gorillas, rhe doesn't have $399 in ki t fo rm or $499 fully assembled. 1<2003 is the bass grunt It sounds great init s stock configuration, only tcn that manr but ean really be dialed-in wilh a few inches push-pul choice parrs upgrades and tube substitu long, and amps have, tions. We recommend that builders weighs in al but the replace the stock diodes with HEXFREDs only eight K2003 also whe:n Ihey first build [his kit. The: few pounds. has less grain eXtra dollars invcned at the: beginning are: OUtput is I';ue VACUUM , U • I VA LLIY I S SUI 1 3 • U L , M A , £ 6 L 6 SHOOTOUT Ihe market than any other time in the last Ultimate 6L6 Shootout 25 years. Electric guitarists have more control o,·er their tone with all these competitively priced new tubes. With the Evaluaflons 01 .20 New and NOS assistance of Groove Tubes, New Sensor Corporation, Svetlana Electron Devices, ay CharlJ. KINI.son and Ron Ve il �ooo All Right1 Reserved and Magic PartS, we were able to assem ble an awesome collection of currently Sin<.:e 1936, the 61.6 has been (he stan dard in professional audio amplification. lis use in guitar amplifiers started with Gibson, Rickcnbackcr, and Fender in the late 1930s and early 19405. Fender amps including the Bassman, Bandmaster, Vibrosonic, Tw in, etc., were the domi nam users of 6L6s. Over the last 60+ years, hundreds of thousands of gUit3T \ r amps have been produced that used dlC' 61.6. Even IOday, Fender, Boogie, Sovtck, and countless other boutique guitar amp a 1- , 0< manufacturers rely on the 6L6 fo r lOne. l' ....� Since the first onc rolled off the RCA tube produclion lines, there have been ', 'I almost one hundred variations of GLGs in the USA and other countries. For this article, however, we will be concentrating primarily on modern 6L6 CYpe5 you can JAN- Pbi/ips 6L6WGB (I980s), GE 6L6GC (1970s) IInd Pbilips 7581 (l980s) buy from your tube dealer or retailer. For more derailed history and discussion of can'tmeasure it, musicians can hear the many older 6L6 CYpe5, check out vrv difference. Solid-state amps are coloToo in available 6L6, 5881 and KT66 types. In issue '4, pages 3 through 11. Please a dry, anificial, sterile WlIy that most gui addition, wc rounded up some of the nOle. this article will fo cus on the 6L6 as tarists simply don', care for. Wire, tranS coolest classic vintage glass including used in guitar amplifiers, because of its fo rmers, resistors, caps, controls, and original Tu ng-Sol 5881s, Genala KT66s, predominance in that market. While sev speakers all add something to the sonic Mullard EL37s, RCA �black-plate" eral vintage hi-fi amps made by Healhkir, coloration of the musical output. Tu bes 6L6GCs and GE 6l6GCs. Note that Mclntosh, and RadioCraftsmen woo can dramatically change the tone and dis NOS audio tubes have been increasing in 6L6s, only a handful of tube hi-fi ampli tOrtion characteristics of a guitar amp and value steadily over the last 10 years. If fiers use the 6L6 today. are the quickest w.ty to do it. By simply you 'vant 10 try some of the NOS types, plugging in another tube, re-biasing your don't w.tit tOO long or they may be priced Why are we doing a 6L6 shootout? In ,m ' and plugging in your guitar, you out of your range or unavailable. audio, every component in the circuit wil rnotice the difference immediately. adds a degree of coloration to the overall The 6L6s reviewed here came in three sound. Even if the scope dopes and meter So many 6L6s, so lillle time! To day, basic cypes: readers say it doesn't exist because they (here are more 6L6 and 5881 cypes on 1, 6L6GC General Electric originally introduced this type in 1959. Plate dissi pation was improved o\'er the original G, GA and GB cypes. Sylvania, Westinghouse, and RCA (black plate) introduced their 6L6GC versions in the following years. The 7581 was the com mercial version of the GC and is some· times marked as a KT66. Most 616 types currently made are simil ar 10 the GC design. 2. 5881 Tung-Sol Electric of Newark, New Jersey originally introduced 588 Is in 1950. They appear to be a derived design from the 6AR6 tube that was developed by WeStern Electric during WW2. The 5881 was a compact version of the 6L6G that was used in e,'erythingfrom 8-52 bombers to Heathkit Williamson amplifiers. Fender used 58815 in its early amplifiers including MullllrdEL37 (1960$) llnd Genalu KT66 (1950s) the Bassman and Tw in from 1954 to 1960. VACUUM !UBI VALLIV ISSUI 13 U L T M ATE 6 L 6 SMOOTOUT To ne Time! For our GLG Tone Fest, we gathered up a unique crew of reviewers including gui tarist Phil loarie (he has a website devoted to the 6L6 tube hnp: Ildiva.cecs.berkeley. edu:801-loarie/blues.hrml), Ron Orr long time guitar amp tech and builder of King Amp lifiers, Greg Cooper (San Francisco jazz guitarist exuordinaire ro lay down the rone), David Bardes, and ourselves. The event was held at Ron Ott's house in Pleasanton, CA. In order to gel the most variation in lone, we used both a Fender Custom 5tral with Fralin pickups and a 1967 Gibson E5335 semi-hollow body guitar. Amps used were a 1971 Fender Black-Faced Su er Reverh (with a 1967 lransformer an l' fo ur ten inch Alnico CTS), a 1999 AlIen Amplification Old Sovtck 5881 (J990s), 5881w.xT (I990s) and Tu ng-Sol58BI (I950s) Flame 40 \vau amplifier and a King Blues Rocker (basically a Marshall JTM-45 cir cuit). The speaker cabinet used with the Alien and King amp had tWO Weber C- l OQ drivers. No effects, signal processors, reverb or other rone altering devices were used in the test. All 6L6 sets were matched with the di gi tal Maxi-Marcher and burned in for several hours, then checked again ro insure close matching. Output tube bias varied from about 30 ro 35 mA per tube for the GLGs and 5881s and between 36 and 39 mA for the KTGGs. Bias current was measured with the Swamp Probe Bias probe. To calibrate our ears, we started out with the classic RCA 6L6GC black plate in all the amps. Then we ran through the rhe other 6LGs, 5881 types and the KTG6s and the EL37. Below is a general summary of u - Ruby 6L6 GC-c, 6L 6GC -RC and 6L 6GC-STR (1990s) the shoorout. Certain g itar amp combi na60ns produced unique results and were made by Genalex, £mitron, and commented on specifically. Mullard (Philips). KT stands for kinkless retrode, meaning that the RCA 6L6GC Black Plate (l%Os) response curve did not have the This tube had a rich fluid warmth inthe typical tmode "kink" in it and clean mode. Played with either the Stear was more linear. Unfortunately, production of the famed KT66 officially ended in the 1970s with the leg endary Gold Lion KT66 that had dear glass with a gold Chj,ltSf! KT66 (1998), Groove Tu bes KT66 (1998) script and a fig- ure of a lion on Marshall also used 5881 s for a short time the bottle. NOS exam in its amplifiers made during the 1960s. ples There are a few derivative 5881s including became very pricey, so a few years ago, they the 6L6WGB JAN Sylvania. were re-introduced by a 3. KT66 - A British beam power tube was few manufacturers. introduced in 1938 by MO Valve and later VACUUM TUBI VALLIY ISSUI 13 U L T M A T I 6 L 6 5 H 0 0 " 0 U T nal Sylvania STR-387 and was an excel lem performer. Played clean, il was full, rich, and balanced sounding. When over driven, it had a rich, solid dist"Onion (One great for most rock applications. Sveclana SV6L6GC (1999) With the Gihson 335 and Alien Old Flam e in the clean mode, this tube was loud and powerful sounding with lots of headroom. In the distoned mode, it was full-bodied, with a nice, chimey response. The Svetlana is a solid and reliable tube for moS[ guitar amp applications. Tesla 6L6GC (19905) This tube has a nice, chimey midrange, but the upper frequencies were a little thin sounding played in clean channel. In Tes /a 6L 6GC (1999s), Sovtek KT66 (1999) and El KT66 (19909) the distoned mode, it was slightly edgy in the treble registers. In other amps it may sound differem. Sovtek 6L6GB (19905) This one had watmth, but not the upper frequency detail of some of the oth ers in the clean mode. When it distorted, the rune was not as even or controlled as other tubes in this test. Sovtek 6L6WXT+ (1999) A warm hut detailed sound with JUSt the right amount of upper-mid range bite in the dean mode. In the distorted mode, mids were nice and strong. 5881 TYPES JAN Philips 6LGWGB (19805) Sovtek 6L6GB (19905), 6LGGC· WXT(1999) and RC4 6L 6GC "B lackplate" (19705) A modern derivative of the 5881, in the dean mode, this tube had good upper-fre or 335, the RCA generated chimey, warm and no harshncss. We pumped up the bias quency detail and sweet sanies. In the and dl':tailed sanies. When pushed into to 40mA and noted better definition and Ki ng Blues Rocker with the Gihson 335, distortion it had a tight, controlled and even fuller, tighter performance. it had a nice, woody character when detailed breakup. The black plate's awe played dean. It was powerful and Ruby Tubes 6L6GC C some performance was consistent in all (1999) detailed sounding in the distorted mode. three amps, and with both guitars. This This is a competitively priced tube is still the King of NOS 6L6GCs! (made in China) with a soft, warm mid \n the Allen Old Flame amp with the range. Easily overdriven, it had a tilt Strat, it was chimey, warm, and detailed. GE 6L6GC Grey Plate (1%5) towards the treble and was not as powcr Some felt that it was very clos(" to the A nice, and full sound in Ihe clean ful as the Ruby STR. RCA black plate 6L6GC. Overall, a great mode. When kicked intO the distortion general-purpose tube fo r most types of mode it had a powerful sound with lots of Ruhy Tu bes 6L6GC RC (1999) guitars and playing styles. warmth and Strong bass. It was close 10 When played clean, this was a full, rhe ReA black plate, but JUSt a tiny bit musical and chimey rube with a nice Tung-Sol 5881 edgier. upper frequency response. The RC dis Used by Fender in the 1950s, this tube torted easily, but it seemed a little bright had that funky rw:ang whenplayed in the JANPhilips 7581A (19805) in the Super Reverb and bass was not Fender-style amps with a Strat. It was When played clean, this onc had a super tight. However, in the King Blues warm, detailed, and ki nd of had a glassy touch less dimensionali[), and was slightly Rocker it sounded great. sound in the clean mode. When pushed flat sounding. Driven into distortion, it into distortion, it had a slight edge and a had good control and was full sounding. Ruby Tu bes 6L6GC STR (1999) tilt towards the treble side. When played in the King Blues Rocker, it This tube was modeled after the origi- was full-bodied and balanced with zing VACUUM TUB I YALLI'f I 5 5 U I , 3 • ULTIMAT. 6 L 6 SHOOTOUT Sovtek 5881 (19905) Sovtek KT66 RCA 6L6GC Blackplate It appears that Sovtek has made some This bottle resembles a Tung-Sol 6550. The RCA 6L6GC is still king of tone improvements in this tube as the first ver In reality, it is a low-profile KT66 that for Fender and boutique amplifiers. This sions of their 5881 were a little thin will fit in most 6L6 amps. In the clean tube simply has a rich and smooth sonic sounding in the mids. This latest 5881 mode, this tube was \'ery musical. When presentation. It is very harmonically bal· had beuer mids and bw response when pushed imo distortion, it was not as full anced and just sounds right. Beware of played with the Gibson 335 through the sounding as rhe other KT66s in this test. Japanese copies made in the 1960s that King Blues Rocker Amp. It sounded may be rebranded as RCAs. Blackplates decent in the overdriven mode with full Mullard EU7 (1959) art getting scarce and the price just keeps rising. Get your supply now. mids and highs. Vintage Mullard EL37s have a premium tone with derail, richness and warmth. In Sovtek 588 I WXT+ (1999) the clean mode, the EL37 is balanced and Ruby Tu bes 6L6GCSfR A nodceable improvement of the stan full sounding. It sounded awesome over Magic Parrs really did their homework dard Sovtek 5881, the WXT really rocks! driven with both the Fender and Cibson. with th eir Ruby Tubcs 6L6GCSTR. This Played clean, it had impressive, full mids tube is designed after the legendary STR- and was nice and chimey. When overdriv 387 Sylvania that was used in the original en, it had great diSlOrtion and sustain. Mesa Boogie amps. Clean tones were This tube definitely exceeded our expecta OUR FAVORITE 6L6" warm, fu ll and sweet. Distortion is full tions in that it sounded better than a lot bodied, balanced, and well-defined. The The fo llowing were our favorite tubes of of the NOS stuffOUt there. If you want Ruby 6L6GC-STR worked well in all the this shootout in no particular order of great tOne on different combinations of gear during this a budget, the Sovtek preference. Your own results may vary 5881WXT is your bottle! test. This is an excellem tube ror most depending on your amp, its state of repair, rock guitar applications. The Ruby STR and your guitar: is a Best Buy in the 6L6GC types! KT66 TYPES JAN Philips 6L6W GB Sovtek 5881 WXT + This NOS glass is a detaik-d, musical Sovtek has an incredible array of 6L6 Genalcx KT66 (19605) and warm tube with both single coil and and 5M 1 typetubes available for most In the clean mode this classical glass humbucker guitars. When ki cked into musical tastes. It worked hard to im rove had sweet fullness and chime. Chords overdrive it screams and remains very its existing 6L6/5881 designs as wdr as and single note leads sounded extremely tight.sounding. These are super rugged introduce 5Qme new types. We were all defined with a powerful bottom-end. tubes designed for extremely brutal condi impressed with the performance of the When overdriven, distOrtion was sweet, tions by the US military. They are made 5881WXT +. This is a tube with balanced balanced, and easy to COntrol. with genuine US craftsmanship and atten sanies, a strong-full-bodied botrom end tiOn to quality and materials we will never and lots of chime in both clean and dis Ch.inese KT66 (I999) see again. WCBs can be bought rrom toned modes. In both the Alien Old mOSt NOS tube dealers for under $20 Flame and the King Blues Rocker and Almost an exact look-alike 10 the (2000 price), so get your lifetime stash with both the Strat and the ES335, tone famous Genalex Gold Lion clear glass now! was consistently musical and very pleas KT66, this tube was very balanced and ing. Overall, this tube is a Best Buy in musical with Strong bass. This tube KT66 (Chinese reissue) the world of 588h! would be great for fu ll·sounding rhythm The Chinese version of the Cenalex guitar. In diSlOrtion mode, it was lively KT66 was well liked by all the reviewers. Some Parting Thoughts and huge-sounding, perfect for rock This tube has a powerful fu ll-bodied power chords and lead, especially in a Our subjective opinions in this tube sound; it is chimey and has great overall Marshall-type circuit. shootout an:: based upon the tubes, guitars definition. Sound character is balanced in and amps we used during this evaluation. El (Yugoslavian) KT66 (19805) all musical registers and has smooth If you try this at home, your results and response. Overall sound is very close to preferences may be different. This article This tube looks like a junior KT90 and is the original Genalex, but a whole lot less is designed to inspire guitar players 10 not currently in production. In the clean e.xpensive. Remember that KT66s are experiment with their tone by trying dif mode, it sounded kind of flat and was less twice as large as a stand:.ud 6L6, so clear fe rem tube ty es. We encourage you to do p dimensional in the midrange. Distortion ance in your amp may be a problem. This some tube rolling of your own; it is fun sound was a little bener, but slightly on tube is a Best Buy in the world of KT66s! and besides, you may learn something. the edgy side. USE CAlITION! Remember thal you are Mu.llan:i EL37 dealing with high voltage and !?Ower tubes Groove Tubes KT66 (1999) EL37s are magical and rich sounding. A get very hot, so use insulated g10\"CS when This is a balanced and smooth sounding full-bodied, balanced and ehimey rube in removing them from amps. tube in rhe clean mode. When overdriven clean and distorted modes, this tube does Note thal many of the new 6L6/5881 it was sweet and powcrful with nice everything right. It had sweet, extended types tested here are also available from breakup. According 10 Groove Tubes, highs, excellent mid ran e definition and g companies like Groove Tubes and others their KT66 should only be used in ampli deep bass. EL37s can also handle high in pre-tested graded pairs and quads. Also, fiers with no more than 450V on the voltage really well, but arc physically taller OEMs can fine· tune their amp design to a platcs of the OUtpUt stage. When ki cked in than an average 6L6 or EL34. These specific 6L6 type and it will perform very 10 overdrive, it distorted evenly, especially tubes were ori inally used in tube hi-fi g well, while olher tube types may not in the Super Rcverb amp with the Stral. amps during the 1950s and 1 960s. .sound as good in that amp. VACUUM TUBI VALLIY 1 S S U • • 3 la A CATHODl FOLLOWIR A M P L • • • needs lO supply the full outpUt swing at the output uansformer plus any losses in A Cathode Follower Amp the Output tube. At 5 wattS Output, 81 volrs rms was measured at the cathodes in Single-Ended Mode and 94 volts rms (266 volts peak-tO-peak) 6528 was measured at the grids. The somewhat By John Atwood 02000 All Rights Reserved higher voltage loss than expected is due lO internal resistance in the output tube. To generate this large drive voltage with low The cathode follower as an outpUt stage = 6336 (mu 9 vs 2.7). This beefY distOrtion required a good low-mu triode, has intrigued audio designers for decades. graphite-plate tube was designed as a volt the GAH4GT (originally designed for TV It promises very low OUtput impedance age regulator and has a total ahsolute vertical amplifier service) run from a high and low distortion, both due to the high maximum plate rating of 60 wans. In this B+ supply. The plate resistor is amount of lucal fe edback in the output (440V) amplifier, the wral dissipation is about 40 fairly low in order lO drive the 47K out stage. The big difficultywith a cathode wam, so rhe mbe is comfonably within put grid resistOr. The first stage uses either follower stage is the very high grid drive its limits. A One Electron UBT-l SE out- a 6SL7GT or its rugged equivalent, the voltage needed on the output put transformer couples the cathodes 5691, with its sections paralleled. rube, since there is no volt to rhe speaker. In this appli- Running from a high B+ supply insures age gain (and in fact cation, onlX � 14: I very low di stortion in this Stage. sometimes a sub ratiO IS stantial loss) in needed [0 The power supply may seem a bit exces that stage. drive an 8- sive, but by using separate supplie.� for However, if well ohm load, every stage, interaction between stages is implemented, a so the nor- minimi:/:ed. Bruce has fo und that this cathode-fol mal 16 technique really has good sonic benefits. lower amp ohm tap Surplus Triad (now Magnatek) transform can be an becomes ers were used, but any other combination excellent the 8 of tra.nsformers with specs similar to those performer. ohm rap, on the schematic can be used. The power the 8 resistOrs in series with each filament sup The ampli becomes ply were added ro bring the filament volt fier described here the 4, etc. ages down lO 6.3V with a line voltage of was built by Bruce The pitfall in 120 volts. Without these, the filament Tilden, a California amp down-shifting the voltages wete well over 7 volts -- shorten restOrer and builder. Several of the impedance in a ing tube life. design conceptS seen in this amp, such as transformer is that the separate power supplies for each stage and high-frequency response The 1500 pF capacitor across the cath all octal tubes, are hallmarks of Bruce's suffers due to leakage ode resislOr of the 6AH4GT is some designs. Bruce is a designer who has built inductance and Stray capacitance. "cathode compensation" to help counter a lot of amps and carefully listens for However, the UBT-l has a very good high act the Miller effect in the driver stages. what makes them sound good. These frequency response, and is nor a problem The amplifier putS OUt 5 watts before anribures arc then incorporated into his here. Bruce cleverly uses the 165 ohm pri dipping, and has 1.6 % THO at 2.5 designs. mary DC resistance to bias the tube, gen watts OUtput. The fr equency response is erating the 26 volts needed to run the down -ldB at 20H:/: and 27KHz. For lhe outpUt tube, Bruee used a tube at 160 mA. If you substitute a differ 6528, which is a Chatham-designed dual transformer, make sure it has a prima A pair of these amplifiers were audi triode that is a high mu brother to the em ry resistance of 165 ohms! tioned in several local enthusiasts' homes and were well-liked. The amp has a bal It may be necessary anced, clean, and more accurate sound • to select the 6528 so than most single-ended amps, yet doesn't that the sections are sound at al! like a transiSlOr amp or push matched within about pull amp. It works well with all efficient 10 mA or so. This can speakers tried, but seemed to work espe be done hy letting the cially well with a vintage full-si:/:ed tube under test warm Klipsch corner horn. This may be up, then measuring the because its low output impedance voltage across either damped the bass boominess that occurs the I ohm cathode when the speaker is up against masonry resistOrs or IS ohm walls, as it is in my house. This particular plare resistors and speaker is also hyper-sensirive to any using Ohm's law (r = grunge or edginess in the amplifiet, and ElR) to calculate the the cathode-follower amp came out very current in each section. well here. All in all, this unusual amplifi er performs well, yet is straight forward to In order to use a build. cathode fo llower OUt put Stage, the driver •• • 6528 Amplifier Wiring Layout VACUUM , U B E VALLEY I S 5 U I t 3 • O.sA 'X5CT L-"-",'-C-+--<-'�-"-1------r------L-----' ,. ::.".:,:;.s POWIr 120VAC Inpul 5101( ,�. 2.151< 'W 6528 Cathode Fo llower Amplifier Schematic Celebrating our 10th Anniversary 1988 - 1998 Our 1998 Calalog & Design Manua! is nowava ilable featuring tonskits. 01 parts. books, software. schematlcs. fun projects and the usual into. Ifslust $12 U.S. DJ and Canada, S18 1nternetional, refundable. Visa and Mastercard Weloome. P. O.Box260198 Littlelon. CO 80126 USA lel: 303,470.6585Wel�orne fa�: 303.791.5783 la�s e-mall: wiabsOj�_netcom.com • j SUBM N A T U R I TUB E S Tube Dumpster: Subminia,ure 7ypes By John Atwood Cl20Q0 All Rights Reserved Some of the more obscure types of ing a very simplistic doppler radar (similar [Ubes, at least [Q the average [Ube enmusi in concept to police radar) into the fuse of as[, are the subminia[Un:s. They have the artillery shcll, no adjustmentS were become more noticeable in the market needed, and the shell would explode close place recently, since the US government ro the plane. A simple 5 tube circuit was has been liquidating its [Ube reserves. But developed -- but the tubes need!':d to be are they any good? They have funny part very small and had to withstand numbers. How do you use them in cir 20,000Cs! Raytheon and Sylvania devel cuits? This article will give a short history oped tubes for these shells and started of subminiature tubes, descriptions of the producing enormous amountS of them. size gave them very good VHF and UHF more common types, and ideas on how to Although the proximiry fuse hecame avail performance. Once military equipment use them. able late in me war, toey were instrumen designers got f� miliar with them, they got tal in reducing losses due to Japanese designed into all sons of equipment that History kamakazi pilots. didn't necessarily need their small size: The first subminiature tubes were devel After the war, both Raytheon and shipboard radios (e.g., AN/SRR-13), ana oped in the late 19305 as ultra-low power Sylvania looked for ways to keep their log and digital computers, and other mili battery tubes for h!':aring aids. In America subminiatute production lines running. tary equipment. They were getting in 1940, Raytheon brought Out he first t Raytheon had concentrated more on the designed into avionics up until 1960, and subminiatures: a flattened envelope with battery type tubes, and found a ready since this equipment was manufactured the l!':ads coming out one !':nd in a flat market for them in hearing aids and for adeast several years and had lifetimes press seal. This construction became portable radios. Sylvania, who w�s making of 10 to 20 years, subminiature tubes were Raytheon's hallmark style for subminia mainly 6.3V heater-cathode types, had in activ!,: use in aircraft through the early tures. Hyrron fo llow!':d with a lin!': evenof more of a problem. It [Tied convincing 1990s. It is believed that the communica smaller "Super Bantam" hearing-aid tubes. manufacturers to use them in consumer tions equipment in the Mercury space During World War 11 nothing was heard equipment -- but most manufacturers program used subminature tubes. about subminiatutes, but behind closed were JUSt beginning the transition from doors they were a k!':y part of on!': of Raytheon and Sylvania were the major octal to miniature (7,9 pin) tubes and America's secr!':t weapons: proximity fuses manufacturers of subminiature tubes, each couldn't be bothered with these tiny «pen for anti-aircraft shell and bombs. with theit disrinctive designs: Raytheon ci r tubes. The only successes in thc com with the flar-press base and Sylvania with mercial field (outside of avionics) were in Normal anti-aircraft pracrice requited the round 8-wire base. Both made hattery a few special applications in test !':quip that the gunners manually set timers in types and 6.3 vo l t types. In military mem, and in the lunchbox-size portable the shell fuses [Q explode at the estimated equipment the Rayrheon types dominated police radios of the 19505. altitude of enemy planes. This was a time in the battery applications and were sec consuming and error-prone process that It was (he cold war that really drove up ond-sourced by Tung-SoL Sylvania types reduced the effectiveness of anti-aircraft the volume of subminiature tubes. As the dominated in the 6.3 volt applications. defenses. If the planes dropped to a lower Army and Navy tried to pack more Many of the 6.3 volt types and a few of altitude, the shell would whiz right by sophisticated radio systems inro backpack the battety types were also manufactured them and explode tOO far away. By build- and hand-held units, battery-ty e sub- by RCA, CE, Sonotone, Philips, and � . mllllatures Mullard. In England, Hivac came out were essen with its own line of battery slIbminiatures. tial. Their Interestingly, both the initial developers of compaCtness the subminiature tubes were among the and rugged last American tube manufacturers. ness made Raythcon and Sylvania (Philips ECC by them just this time) both shut down their subminia ri t or ture tube production lines in the late aVlOIllCS�h � - 1980s. where most of the 6.3 Var ieties and 26.5 There are four general varieties of sub voir sub miniature tubes: 1. Battcry tubes. These miniatures are almost all Raytheon flat press COII went. sTruction. 2. Flat-press heater-cathode Missiles types. These are almost exclusivcly made were another by Raytheon. 3. Round-base heater-cath Favorice use. ode types. These are mainly Sylvania- 5647. 6BEl. Their small- VACUUM TUB I VALLEY I I 5 U I , 3 .. 5 U B M N A T U R I TUBI 5 dtsigned, with other companies (including S.3V Raytheon) scrond-sourcing the popular Heater-Cathode Tubes types. 4. Miscellaneous types. The: banery types range from ultra-Iow power hearing-aid types (such as the: CK512AX) ro relatively higher-power typeS used in port:.lble military tr:1r15mit ters (5676). Most of the.s<: tubes arc pen todes, since they C:.In eke OUt the mOSt gain possible with the: least filament power. Banery tubes norm:.llly have :.I rep . utatIOn for high microphonies in audio uses, but the subminiatures are rugged enough 10 approach regular miniature tubes for microphonia. The heater-cathode subminiature tubes were often modeled after conventional miniature tubes and mOSt have similar characteriSlics. The accompanying table listS the most commonly-found types that would be of interest 10 audio designers. Single and dual Iriooes are common, and 1.25V make good audio tubes. They are quiet Fllamentary Tubes and have reasonably-Iow distorrion. Note that the medium-mu triodes (6AK4, 5703, 611 1) have nearly double the transconducranee of, say. a I2AU7. A few of the later tubes (7963. 7995) arc com petitive with the high transconductance miniature tubes. Not listed are audio and video OutpUt tubes. diodes. dual-conuol pemoocs. and low-mu regulator uiodes. Also not lined are tubes with 26.5 voh Miscellaneous Tubes hC:.lters. The miscellaneous types include high voltage rectifiers, gas regulators, electrome ter tubes. corona discharge regulalOTs (made by Victoreen). thyrauons. and oth ers. Gm and Rp are at stated Ep (plate voltage) and Ip (plate current). For more intomaUon, refer to GE 'Essential Characteristics'. During the 19505. Bendix was contract ed to develop subminiature versions of attractive, since th� noise and unreliability maximum plate voltage rating for most power tubes, including the 6L6 and 6AS7. of dissimilar metal contaCt is avoided. hcater-cathode types is 150 to 165 volts. Ceramic-meral prototypes were construct Soldering very close to the glass envelope The reliability s[Udies recommcnd no ed, but never went into production due to should he avoided, though. higher than 125 volts for longcst life. problems with their vcry high operating temperatures. Ev�n rhoucll subminiature tubcs arc Food for Thought very small, their power dissipatioll is only Subminiature tubes were the fo cus of Application moderntely lower than miniature tubes. As intense development during the 19505. a result, their bulbs can run very hot. Data on 5ubminiature tubes can be Some of rhe possibil ities of what these Packing lotS of tubes in a small space fo und most easily in the General Electric tubes could have: become is hinted at in aggravates this heat build-up. Studies of �Essential Charncteristics" manual. It cov the last paragraphs of reference 4 (italics subminiature tube reliability show that, ers mOM types, except fo r some: of me spe arc in original text) : cialized Raymcon types. although the maximum bulb temperature 220°C, rating is they arc mOSt reliable Super Reliability - an Attainable Goal Subminiature tubes can either besocket below ISO"C. Interestingly, if the bulb Tk foctthat high rtliability artas exist is ed or wired directly intO the circuil. The temperature is below 1 OOGC, inter-element wrifitd byrk prtStnU in n;ny tts! of a socketS are 7 -pin in-line or 8-pin round leakage becomes a problem. In milit:.lry group of rm km that exhibiud link or no sockets, which, by the way, evolved into C VA CUUM T U 8 E VA LLIY I S SUI 1 3 • . SUBMINIATURE TUB E 5 I KLIPSCH 20,000 hours. in one such teu involving 60 forth the KJipschorn Jubilee. Jubilee was lB. "Modulation DiSlOrtion in Loud.pe:lken;." dual-gClion tubes, no catastropbic failum chosen by being borrowed fr om the Journal of the Audio Eogineerngi Sociery, April, I969. had occurred and all characttr is tics wtrt Jewish tradition where the Jews freed their within initiaL limits on rvtry secrion after servantS after 50 years and returned 50 19. "Modularion Disrortion in Loudspeaken;, 16,000 bours of oprration. Also. no signifi years accumulative properties. After all, Part ll,' Journal of the Audio Enginccrni g cant slumping of characttristics occurred in the light bulb has enjoyed many improve Sociely. February, 1970. tht Unt 5,000 hours of the tm, makin it ments since Thomas Edison invented it g 20. "Loudspeaker Perform,wee." Word.,...World. impossible to use exrrajoiation mnhods to over 100 years ago. February, 1970. mimate the end of life due to characteristic dq;radation. List Of Published Papers by Paul W. 2i. "Delay [ffeclS in Loudspeakers,· Journal of Klipsch: the Audio Engineering Society, OCtober. 1972. in dications are strong tbm this {eveL of euc I. "A Low Frequcncy Horn of Small 22. "Modularion Disrorrion in l.oudspeakers; tron tube reliability i, pOISibkfor many Dimension.," The Journal of the Acoustical Part m," Journal of the Audio Engineering app lications, provided proper choius are Society of America. (k'obe" 1941. Reprinted Sociely, December. 1972. made with resp((t to tube typ e and op eTat by the Journal of the Audio Engineering ing conditions. The operating conditions for Sociery, M�rch, 1979. (In 1978, P�ul Klipsch 23. "Projecr Notes/Engineering Briefs: 1. A Note high "liability recomrnmded in th is book was �Wllrded ,he AES Silver Medal for this p�per.) on Modulation Distortion: Coaxial �nd Spaced provide an excdlmt slartingpoint for mak TW e<:'cr - Wo ofer Loudspeaker Systems. 2. A 2. "Improved Low Frequency Horn," The Nore on Modulation Distortion: Two ing such choius. With subsequmt refine JoW"nal of the Acoustical Socety of America, i FrequenciesRadiated Ftom the Same mmts based on cartful studies offitld exp January. 1$143. Diaphragm," Journal of the Audio Engin eering rimu, electron tube reliability could "ach a SocietyApril. 1976. uvd thought impossible onlyflw years ago. 3. "A Notc On Acoustic Horns: Proceedings of the Institule of Radio Engincen, July, 1945. 24. "Loudspeaker Distortion.· The Institute of Reprinted by the Journal ofIhe Acoustical This was published in 196 J. It's wo bad Electrical and Elecuonics Engineers, April, Sociery of e i a the nansiswr came along w swp this Am r c , January. 1946. 1976. devdopment. 4. "A High Qualil)' Loudspeahr of Small 25. "A Note on Loudspeaker Impedance and its Dimensions.· The Journal of the Aeou$lical Effects on Amplifier Distortion," Journal of the References: Society of America, January, 1946 Audio Engineering Society, July-August, 1978. I. "Radio Proximity Fuze Development," 5. "E..:periences in Stercophony," AUDIO. July, W. S. Hinman, Jr., C. Bruneni, 1955. Proceedings of the I.R.E, Dec. 1946, pp. 976-986. 6. "Room Dimensions for Oplimum Lis'cning and ,he Half"Rwm Principle," IRE TransaCl;ons ™ 2. "Proximity pUles for Artillery," H. On Audio, January· February, 1958. SIL VER SONlC Se!vidge, Electronics, February 1946, pp. 7. "Stereophonic Sound wirh Two Tracks, Thrcc Audio Cables 104-109. Channels byMeans of a Phantom Circuit," Journal of the Audio Engineering Soeiety, 3. 70 Years of Radio Tu bes and Va lves, April, 1958. John W. StOkes, The Ves tal Press, New Making the High End York, 1982. B. "Subjective Effecrs ofFrequency Modub,ion DiSlOrtion," Journal of the Audio Engineering Affo rdable! 4. Subminiature Electron Tube Life Sociery, April. 1958. "With tube amps and hybrids, the Factou, M.W. Edwards, D.E. Lammers, 9. "Corner Speaker Plocemenr," Jouroal of the Silver Sonic competed with the best." J.A. Zodlncr, General Electric Co., Audio Enginttrin g Sociely. July, 1959. Bound for Sound Engineering Publishers, Elizabeth, N.]., 1961. 10. "Wide Srage Slereo,8 lRE Transactions on Audio. July-August, 1959. 11. "Experiments �nd E.periences in Stereo," IRE Tr ansactions on Audio. May-Ju ne, 1960. Continuation5 of Klipsch In terview from Page 12. "A Speaker System wilh BaM Back-Loading of Unu.ual Parameter Valucs,� IRE Tr ansactions on Likefashion clorhing slyles, some ideas seem Audio, July-August, 1960. to fall from fawr and thm "turn to vogue. in one of your white papers you mention lis ]3. "Signal Mutuality in Sereol SYStems," IRE teners becoming tired of boomy bass response TransaClions on Audio, Sep,ember-Octoi><:r, and the trend away from in-wail speakm. 1960. That was sixtyyean ago, although it seems 14. "Polarily. Phase. and Geometry," IRE Silver Sonic T-14 Speaker Cable like you're discussing the audio situation Transactions on Audio. January-February, 1961. Silver Sonic BL-l Series !I Interconnect today. Wh at other trmds have you sun come Silver Sonic 0-110 AESfEBU Digital around again? 15. "Eight Cardinal Points in Loudspeaken; for Silver Sonic 0-75 Digital Cable Sound Reproduc ion: IRE Traruactions On l Hook up wire & Connectors History repeats itself. The Klipschorn, Audio, November-December, 1961. which was first marketed in 1948, has 16. "Stereo Geometry Te sts,· IRE Transactions D.H. Labs. Inc. experienced 50 years of modifications, on Audio, November-December, 1962. 612 N. Orange Ave., Suite A·2 some of which have been improvements. Jupiter, FL 33458 I believe the fo rthcoming paper by Roy 17. "A New High-Frequency Horn," IRE (56 1) 745·6406 (phoneffax) Delgado and myself will expose the suc Tr ansactions on Audio. No,·ember-Decemi><:r, www.silversonic.com cession of the improvement that brought 1963. VA CUUM TUBE VALLIY I S 5 U I I 3 • suaMINIATURE T U a I S / KLIPSCH Proximity Fuu Artill":,! 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Only $16.95 ooch Newl VfV Tube Head Boseball Cop 1 ()()%(0Il00, one sile �Is all ladjuuoble bond) Navy Blue Only S 18.00 each Shipping ond Handling $5.00 US, $6.00Conoda, $10.00Europe, $12 �ia and Wond California Residents odd 7.25% Stote Sales Tax Vacuum Tube Valley, P.O. Box 1499, Lakeport, CA 95453 USA FAX 707-263-7648 www.vacuumtube.com -- • Back Issues, Books, Goodies, & Subscriptions VJV# I Spring 1995 $8 Vintage Hi-Fi Spotter's Guide-Volume I Vint�gc Dynaco Tube: Equipment - 1955-77 Over 450 photos & spttifications of tube audio gcar History and Testing of th� 12AX7/ECC83 dual rriode from the Golden Age of Hi Fi. 86 pp. $18.95 Tube: Tes ting Methods + Early Amplification and Amps Vintage Hi-Fi Spotter's Guide Vo lume 2 . 1 COveTS r-�� .,:I Volume 2 equipment not listed in Vo lume 1. VIV#2 Fall 1995 $12 Almost 500 amps. preamps, tuneR, etc are depicted. _ n _ Hcathkit - Thc Tubc WiIlWn$On Years 1950-6\ ...... Edi tion CO\'l:U early audio and includes a Speaker section EL34/6CAJ History, Ty pes and Tens 1"'1'1 wilh mon vimagemanu&ctureu. 88 pp. $18.95 ...... Magnum SE EL509 Amplifier Project by DaVl: Wolzc - 1927-34 Western Electric TheoltCr Sound Systems Vl Dtage Hi·Fi and Audio Price Guide 2000-2001 .. "" Updated price & grading guide fot almost 1,000 vintage VIV13 Winter 1995196 $12 n,.,_ .... hi fi amps, p=ps and IUneR. Includes Vintage pro Eico Mono Tube: Ge:lf - 1955-62 audio and theatcr gear. Also, pro loudspeakers, N.O.S. A1re.:; Lansing 604 Coaxial Loudspeaker History vacuum tubes and audio rransformers. $20.00 f. F-o�- 8 Western Electric 300B HislOry and Umning Tests 101:. 300B SE Tramformcr Lil!(�ning Te sts "Vintage Hi-Fi The Golden Era Video" A on�f·a kind video covering the classic post·war and #4 1996 VIV Spring $12 19505 home hi fiera. Ov.:r 80 dusic audio amps, pre , 6L6 History Types and Listening Tests amps tuners, are shown. This video is probionally pro- Vinugc' Bookshelf Speaketl 1955-1965 duced. 34 mioVHS NTSC $20.00 Early FM Broadnsling HiSTOry HK Ciallion [ &. 11Amplifier HiSTOry and Mods The U1timate Tu be Substitution Guide No IUbe electronics enulll$iur 'should be wilhout Ihis VTV'5 Fall 1996 $12 book. Over 10,000 tubes are listed on 240 pages includ· The Ultimate FM Tuner Shoot Out ing: audio, radio, muumilling, and special. Features an Red Bank Guided Missle Tubesfor Hi-Pi audio [Ube section with [Ube eV ORDER FORM N=, ______Date______Subscribe To Vacuum Tube Volley � Ad ______�------�------___ The Cl05si( Electronics Journol C;'Y-- --::::---=--,,-----::---,-- Srate----- .Zi p,------:c____ $45/year us First Class S48/Canada, Please Send Me The FoUowing Produeu S56/EufOpe & $66/Asia & Wo rld $,__ $,__ VACUUM TUBI VALUY $5. 00 p.a. Box 1499 Add S!Jipp ingper orderin USA I Add$10.00- Per ItemFo reignAir S!Jipp ing $,_ __ Lakeport, CA 95453 USA CA 7.25% _ _ Residents Add Stare Sales Tax (CA Tax) $, _ PIIone (707) 263-5881 FAX (707) 263-7648 Credit Cards, V.S. BankChecks or Money Orders OK TOTAL ORDER $,_ __ emoil • [email protected] Credit Card_ '1 ______Exp. Date ____ Signature______www.vacuuntlube.cont www.AudioWeb.com The Largest Hi-Fi Site on the Internet [. ,. y- '...... [ ...... - .. .. ., , Cl 't,I• oJ "'" "" ,"m "- ,- .... ,. AQIt... Jel .... l�."i.;;.,,;., � �� Audio's Home on the Internet Since 1� Welcom. 10 AudlllWeb. w.... Ag.!tWt tYt" Q1l1vA H.... ' .. . """" Accessories Loudspeakers SI H _ Ampl"n,rs Mise. Electronics Books & � PubllcatJons fI!I! Instruments Cable PhQno � .-, CDlDlgi tal Equ ip _ PreampH I.rs l Headphones _ Sound IJ Processing 11 Video Pm.. eM IlIu&diMI:.! I[... .. ,he Il!Ul.I!IlI1 .. ... � Shopping ' Reviews . Classified Ads . Auctions Links . Directory . Discussions . Newsstand Audio's Home on the Internet Since 1994 AudioWeb.com, PO Box 303, Ber1l:eley Heights, NJ 07922, 908 464-7307, 908464-0271 (lax), [email protected] • �urbtpors of "((lassie" \[ransformtrs & (fnelosurts Single Ended,Push-Pull Fi lter Chokes and Potted Tu be Output Tra nsformers Aluminum & Steel Chassis and Oiecast Aluminum Enclosures Open & Enclosed Filament Tra nsformers High Voltage Plate Tra nsformers Contact us fo r a free cata/og & list of stocking distributors 4700 Genesee SI. - Cheektowaga, NY 14225 USA Phone: (716) 631 -5700 Fax: (716) 631 -1 156 394 Edinburgh Rd., N. - Guelph, Ontario N1 H 1 E5 Canada Phone: (519) 822-2960 Fax: (519) 822-0715 www.hammondmfg.com • ------. e are a proud dealer of Western Electric Audio Products. The current production 300B is now in stock. W Electron Valve stocks a wide array of NOS Vintage Audio Tubes like Mullard EL34, ReA 2A3, and Mullard 5AR4. We also L��;] have a good stock of Old Production Your source for hard to find Western Electric tubes such as 205810, 252A, 274B, 300B and many others. Vintage Audio Tubes Electron Valve carries Precision Tested Ram Labs and Quality Vacuum Tube Reference Tubes. These tubes are computer tested, graded and matched to ultra high specifications predetennined by Roger A. Audio (omponents Modjeski. We also cany the Music Reference 1iI=tRM·]O (Push·Pull 6BQ5, 35WlSide) Stereo Amplifier and the SII, �J ler 11�!ill ll !11 1 4111illd 111111111 11 111 Jlli.m! Mmil·C Reference RM·200 (Push·PuIl 6550, www.electron-vatve.com • Email:info®eltl::lroll-Vatve.C(lID http ://www.triodeel. com Check out our site for...... OEM tube data, schematics,links to nearly 200 tube related sites all over the net, plus lots more ... World famous Dynaco upgrade boards, simple & effective •.. Magnequest replacement transformers for Dynaco(tm) ... Upgrade chassis for ST70, complete & partial kits ... Tubes:JJflesla,Svetlana, Sovtek, Philips, NOS ... capacitors, resistors and a potpourri of useful stuff ... more to come... new EZ-Build modules, (cheap hi-end for everyone!), new paper capacitors, & the list goes on.. trio de L 2225tr Wiode Roscoe SI, electronicsChicago, IL USA Ph 773-871·7459 Fax 773-871·7938 Office hours 12:30-8:00 CT MlF (or until ....get tired or thirsty) I-=���...... Email us atpostmasterOtrlodeel.com _w. , ·Worldwlde Service,Neighborhood Prices" • The Shape of Great Sound SveE l E CT R ONtlana DEVICES Sveilana Audio Tubes ignite music with a richness and www.svetlana.com clarity only achieved with the best in vacuum tube technology. At Svellana, we start with quality materials, then add precision and carelul testing, The resulting sound is rich, full and powerfu l. So your amplifier gives its best performance. SveUana Audio Tubes are shaping the way you hear music. Headquarters: 8200 S. Memorial Parkway Huntsvilie, AL 35802 PhoM: 256-882·1344 Fax: 256-880-8077 Engineering 8. Marketing: 3CXXlAlpine Road Por\ola Valley, CA 94028 Phone: 650-233.0429 Fax: 650-233·0439 • A2 10 Wa tt Stereo Amplifier ..."'" 219E CAS Speakers 10 Watts RMS/channel Tube Rectified (5V4G) 2x6EAB, 4xEL-84 Point to Point Wiring Low Noise High Quality Parts Superb Sound Quality Sensitivity: 91.Sdb (1W at 1 Meter) Max. Power RMS: 60 Watts Dimensions: 16"H. 10"W, 7.25110 Light Oak or Black Oak Finish Complete quality kit audio system for $749 or fully assembled for $939. Includes speakers, amp, and cables. 6717 NE 1S1st st. Kenmore, WA 98028 '-877-480-8866 or 425-485-3836 E-maU: asusaOearthlink.net Website: as-usa.com • VACUUM TU. I VA LLIY VTV Pro-Tube Shop Legendary Tube Knowledge and Performance P.O. Box , Lakeport, CA 95453 USA phone (707) 263-5881 (707) 263-7648- FAX www.vacuumtube.(om Illinois Capacitors Illinois Axial Electrolytic Can Electrolytic ICMWR Metollized Polyesler Capacitors Great Value and Capacitors (63OVck rating) very dependable. 20,20,20,20 @475V O.OOluf SO.80 eo 3.3vf @350Y $1.20 eo iMaIk>",type) $29.00 0.002uf SO.80 eo 4.7vf @350V 5l.45eo SO+SOuf @SOOVlCR 0.0047uf $0.80 eo lOuf @450Y $1.60 eo w/domp S21 .5O 0.OO68uf $0.80 eo 22uf @250Y $1.95 eo 100,I00uf @SOOV 0.01 vf $0.90 eo 22uf @450Y $2.25 eo LCR w/domp S28.OO O.022uf $0.90 eo 22vf @5QOY $2.85 eo 40,20,20,20uf@SOOV, 0.0.d7uf $1.0090 47vf @35Y $1.50 eo LCR w/domp 0.068uf $1.20 eo 47vf@350Y $2.50 eo $32.00 o.lvf $1.30 eo 47vf @A50Y $3.A5 eo D.H.Lobs Silver 0.22vl $1.60 eo l OOvf @I 60V 52.95 eo Order: By email, FAX. Mail, Phone Sonic Wire 0.47vf $2.20 eo lOOuf @350Y $3.90 eo Minimum Shipping and 1.0 uf (4ooy) $2.50 eo I OOuf @.450Y 54.90 eo Rated as the HIt Handling per order: 2.2uf (250V) $2.75 eo l000uf@2511 $1.75 eo sounding wire for "'e us $5.00, Conoda $10, Evrope $20, 3.3uf (250V) $3.20 eo 2200vf@35V $2.75 eo money by several Asio $25 (Heavier items will require 4.7 uf (250V) $3.80e0 audio publications. odditionol postage) 6.8vf (250Y) S4.20 eo Hovland MusiCaps Silver Sonic T· 1 4 $35 Minimum Order Ultra-Tone Silvered Foil in Polypropylene Foil and Speaker Wire $4.00/ft Paper and Oil Capacitors Film Silver Sonic 8l-1 High Lo�r etched 5ilvered fo il in high· Vintage Hi-Fi Rebuild Kits High resolvtion, greeli·sounding tlm Detnition Interconnect Get Great Sound & Save Bucksl quality haft poper in non·laxic min· cops perfectfor 011 types ofoudio erol oil. sealed in epoxy. (650Vdc ) Wire $3.50/ft All kil$ include 011 new ICMWR signal equipment vP9�' SI3.20 Silver Sonic OFH-20 and bypo!>S fi lm cop�, eIec· 0.01 vf eo o.oluf@I600Y $9.79 eo under-chassis High troIyfics, I woll metol oxide Iow·nai� 0.02vf S15.40 eo 0.022vf@IOOOY $9.82 eo Performence o.O.5lJf eo Si!vet--/TeRon Cheni, Wire plote resislor$, new silicon power wppjy SI7.60 0.033vf @600Y $8.01 eo 0.1 uf $20.90 eo SO.951k diodes ond �hemoric. Kits do not 0.047vf@IKV $1 2.05 eo co eo RCA-2 Gold Tiffony indude FP n·type electTolytics. 0.22uf $30.80 0.luf@600Y $1 1.52 eo Dynoco PAS2/3 $.50 0.47vf Style Interconnect Plug $44.00 eo 0.22vf @600Y $1 4.55 eo Dynoco Mork Ill, Mark IY $40 (for poir) $76.00 eo 1.0vf 0.47vf @4ooy $12.80 eo $10.9500 Dynoco SCA·35, Dynaco ST·70 $30 $1 10.00 eo C Gold Banana Plug 2.0vf 0.47vf @6QOY $21.71 eo 8-1 EICO HF35, 50, 60 $30 ea NEW Ultra Crossover Capsl and Insulator $5.50/pr 1.00uf @400Y $21.66 eo EICO ST70 $60 Solid Silver leadoutsl BSP Gold Mini Spode E1CO HF86 $35 2.2uf @200Y $23.83 eo 1 uf@200Y $45 eo Speaker Te rminals for EICO HF87, Hf89 $60 3.Ouf @200Y $28.45 eo 2uf@200V $70 eo Vi toge Hi-fi $1.10 eo Fimer X·1OO, KXIOO, KX20Q $55 Note: Only the above n 3uf@3OOV $95 eo Fimer X·IO\. X·202, X·202S, C $65 Hovland values in �tock. 1 Meter BL-l Factory 5uf@300V $ 1 45 eo Fisher 400 Receiver $65 Terminated $99 1 ()@300Y $195 eo Tube Sockets Fisher SCXX:, 8008, BOOC Receiver $65 10 foot T-14 Factory ultro· Fisher SA· 1 00 $50, SA300 $85 To ne Silver capacitors ore Octal Ceramic Chassis $3.50 Terminated $119 superb performers. Our customers Octal Ceramic PC mt $3.00 Heath W·2,3,AM $35 eo W·5M $45 ea tell us these are /he smoothes" Octal NOS Phenolic $3.50 Heath SP·2 $65 best·sounding and most musical 9 Pin Ceramic PC $2.50 Mclnlosh C·20, C-I I, C·22 $100 capaci tors available. 9 Pin Ceramic Chassis $3.00 Mclntosh MC30, MC40, MC75 $45 eo 9 Pin Ceramic GOLD $5.00 FREDS (Fo�t Recovery Diodes) Mclntosh NlC60 eo Ultro-Tone Polypropylene 9 Pin Plastic w/shleld $4.00 S.50 IXYS 600Y 8A $3.00 eo Mdntosh MC225, 240 $65 Film & Foil Power Supply 9 Pin NOS Brn Phenolic $3.00 r=c-;---;;--;-;-=:--:-cc::-Ivv",T S I'OOVII A $600• eo Mdntosh MC275 $75 Capacitors (Not Silver Foil} Fa st from our 60V 5 Amp &hollly$ 1.50 � Scolt 130 $80 20uf @ 6SOY $22.00 eo Order Scolt 222, 2228, 222C, D $65 SOuf @650Y S45.OO eo on-line catalog Sco1l 299, 2998, 299(, D $65 100 uf @650Y S60.OO eo www.vacuumtube.com AMEX, VISA, MC OK VACUUM TUB. VALLIY ISSUI 13 •