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Review Denon AH-D7000 Headphones and Headroom Ultra Desktop Headphone Amplifier - April 2009

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Review Denon AH-D7000 Headphones and Headroom Ultra Desktop Headphone Amplifier - April 2009 of and Home Theater High Fidelity review Denon AH-D7000 Headphones and Headroom Ultra Desktop Headphone Amplifier - April 2009 “... this complete system (...) will absolutely KILL any normal hifi system” INTRODUCTION phone ring when the music is on. People can sneak up on me. On the other hand, my My first “high end” system consisted of Sennheiser HD-595s I use at home for late Sennheiser HD-580 headphones, an original night listening have no isolation, allowing HeadRoom headphone amplifier, an Audio office noise to intrude on the music. The Alchemy DAC in the Box, and a Sony Denon D7000s are the perfect compromise. BY CHRIS GROPPI Discman with an optical digital out. I was They are sealed headphones with some a college student at the time, and there was isolation, which knocks down my computer no way of having a real, properly set up hifi fan and other background noise, but I can system in my dorm room. It was clear to me still hear my phone ring and people can get “... frequency response, at the time, listening to both my system and my attention. uber high end Hifi in shops, that my little tonal accuracy, speed and headphone setup blew away many high dollar I first heard the AH-D7000’s in HeadRoom’s agility and even imaging loudspeaker based systems. A headphone- room at the Rocky Mountain Audio Festival and soundstaging (...) are based system is by far the least expensive in 2008, and decided that I just HAD way to experience truly great sound. Many to review a pair. They were, by no small truly spectacular.” of us can’t afford a hifi system costing tens of margin, the best sounding headphones in the thousands of dollars. While the Denon AH- HeadRoom display. There, they were paired D7000 and the HeadRoom Ultra Desktop with the Ultra Desktop Amp, which has amp are not cheap ($2600 total MSRP), HeadRoom’s premium amplifier modules, this complete system (just add disc player or and their premium DAC. I was able to set up computer) will absolutely KILL any normal hifi system I’ve heard costing less than $30,000. Sure, you give up the physical slam of bass, and the large soundstage, but the frequency response, tonal accuracy, speed and agility and even imaging and soundstaging (in their own way) are truly spectacular. I’ve been looking to upgrade my office listening environment. I have a HeadRoom Total Bithead amp with Etymotic ER-4S headphones that I use mainly for travel on the airplane. At my desk, the isolation of the Etymotics is so good I can’t hear my © Copyright 2009 Secrets of Home Theater and High Fidelity www.hometheaterhifi.com Denon AH-D7000 Headphones and Headroom Ultra Desktop Headphone Amplifier - Page 2 op amps available. We use these same op- card also is compatible with ASIO (Audio amps in a preamplifier circuit for milivolt Stream Input/Output) drivers. Typically, all level signals in the radio astronomy audio on Windows machines is processed instrumentation I build for my day job. They by kmixer, the underlying audio engine in cost over $20 a piece in small quantities. the Windows OS. While it is possible to get These op amps are in HeadRoom’s “Max” good performance with kmixer, it is almost amplifier modules, which drive both stereo impossible to tell what kmixer is doing. channels. In addition to the Max amplifier It may or may not perform all manner of modules, the Ultra Desktop also includes the sample rate and bit depth conversion on an Max DAC module, based on the AD1896 audio stream without your knowledge. ASIO a review of this same system, and have lived asynchronous sample rate converter and bypasses kmixer and sends the digital audio with it on my office desk for a few months. the Cirrus Logic CS4398 DAC. The SRC data directly to the audio device without To make a long story short, it is not going upsamples and pads all incoming digital any intervention. Use of ASIO requires a to leave. data to 24-bit 196 kHz. Toslink optical soundcard with an ASIO driver, which was and coaxial digital inputs accept signals at provided with the M-Audio Audiophile DESIGN sample rates up to 24-bit, 192 kHz. The 2496. For some other common soundcards, USB input accepts only 16 bit inputs up to including the USB sound CODEC, a free The Denon AH-D7000 is the latest in 48 kHz. A super high quality ALPS volume ASIO driver called ASIO4ALL is available Denon’s new sealed headphone lineup, pot controls the level, with switchable rear on the web for free download (but only and is meant to be the flagship model. At panel RCA outputs available for use as a supports 16 bit word size and maximum 48 $1000 MSRP, it is a very expensive pair of preamp. Two pairs of RCA analog inputs kHz sample rate for USB). The audio player headphones. Your $1000 does get you a are also available. The power supply for the also needs to support ASIO output. The very impressive amount of craftsmanship. Ultra Desktop amp is external. Included “industry standard” player iTunes, does not The headphones are delivered in a very nice is the third-party Astrodyne switch-mode support ASIO output. I used another free presentation box with a calfskin leather power supply, which can supply up to 42 player, Foobar2000, configured with several front and silk lining (or at least they seem W of DC power, and autoswitches for 110- plugins to approximate iTunes functionality. like calfskin and silk; they may be synthetic). 220V and 50 or 60 Hz. As a $499 upgrade, While it is not as easy to use or as pleasant The sealed backs of the headphones are made HeadRoom offers their own bespoke, linear to the eye, it does offer ASIO output and of beautifully finished certified-sustainable power supply. My test unit included the offers the user complete control over audio rosewood, with Denon logos under the Astrodyne power supply. output. gloss lacquer. The adjustment mechanisms are made from machined magnesium for “... stupendously fast, agile and When used on a Macintosh computer light weight, and have been engineered tonally accurate.” running OS X, iTunes does not have to deal with the precision of a camera mechanism. with kmixer, and does output a file’s native The feel of simply adjusting the headband SETUP (OR AN ASIDE INTO COMPUTER bit depth and sample rate in a “bit perfect” screams “high end.” The Earpads and head AUDIO) manner, as long as the digital interface can band are made from the same calfskin or handle the data. Unfortunately, I am forced calfskin like material used on the box cover. I deployed the HeadRoom/Denon pair to use a Windows box at work to be able to A Y-shaped headphone cord with fabric on my desk at work, fed by my computer run Windows specific software without the cladding is employed, and is made of 7N workstation, a AMD Athlon X2 based performance penalty of a virtual machine oxygen free copper wire with a ¼” stereo machine running Windows XP SP3. Little environment like Parallels of VMware. plug termination. 2” diameter microfiber did I know the effort I would need to go drivers are used, with frequency response through to supply a high quality digital feed With the M-Audio soundcard and from below 20 Hz to 45 kHz. to the Ultra Desktop. I would have preferred Foobar2000 configured to feed the Ultra to use the USB input and iTunes as the player, Desktop native bit depth and sample rate The HeadRoom Ultra Desktop amplifier is a but both these methods offered some serious data through the coaxial digital input, I was perfect match to these headphones. Any high limitations. The Ultra Desktop’s USB input able to get the performance I wanted and performance headphone requires proper can only accept a 16 bit 44.1 kHz input. As I was confident that the system was doing amplification. Just as you would not drive a do have some high resolution digital audio in what I expected. pair of $180,000 Focal Grand Utopias with FLAC and Apple Lossless format, I wanted a $500 receiver, you wouldn’t want to drive to be able to feed the Ultra Desktop with a 24 a pair of D7000s with an iPod. The large bit 96 kHz signal. Most low cost soundcards driver requires power and control to achieve do horrifying things to the digital signal, maximum performance. While the flat 25 not limited to internal processing at 16 bit Ohm performance may seem an easy load 48 kHz regardless of the input signal or to drive, you will not get your $1000 worth desired output signal. I installed a M-Audio without a proper amplifier. The 6”x6”x3” Audiophile 2496 soundcard in the PC. This unit contains a stereo headphone power is one of the least expensive soundcards that amplifier based on the Burr Brown OPA627 offer a fully controllable 24 bit 96 kHz digital Op amp, one of the highest performance output. It is available for less than $100. This © Copyright 2009 Secrets of Home Theater and High Fidelity www.hometheaterhifi.com Denon AH-D7000 Headphones and Headroom Ultra Desktop Headphone Amplifier - Page 3 I recently ripped all my CDs and DVD- SOUND Audio discs to Apple Lossless format and/or FLAC (Free Lossless Audio Codec). Both are If there is one phrase to describe the sound capable of encoding high-resolution audio quality of the Denon/HeadRoom combo, (up to 24 bit 192 kHz) in a lossless manner, it is “jaw-dropping.” One of the main i.e.
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