Hello, I have been working on an no-feedback amplifier an have a prototype in hand. I am seeking critiquing, knowledgeable and critical local listeners who can listen to and comment to me about the quality of the sound as I tweak it. I a couple of weeks I will have a no-feedback RIAA preamp to put to the same tests, would appreciate you help in the final stages of this development process. Thanks, Barry.
Austin, TX amplifier evaluation
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Reporting back here after spending last weekend listening to Barry's prototype of the "Austin Audioworks Thornton-Cohen CCT1". I've never reviewed a product on Head-Fi before, but my day-job is based on critical listening as an Audio Director for a video game company in Austin TX. I'm also a drummer and have been a head-fi lurker for almost a decade.
First off I have to thank Barry for such a unique opportunity to peek behind the curtain of product development. I had a great time talking to and meeting up with Barry (he has a long history in the hifi business and lots of great stories to tell) and an even better time listening to his creation.
The CCT-1 is a current-mode amplifier along the lines of the Questyle CMA800R and Bakoon HPA-21. It is a zero-feedback, Class-A design that supports unbalanced inputs and balanced outputs. The prototype I listened to only has a voltage output, but Barry is planning on producing an updated prototype that includes both a voltage and current output in the near future. The power supply is in a separate box from the amp, and Barry indicated that he wanted to keep the final version as separates as well. It is currently all-hand built and a bit fragile (Barry literally told me to "give it a good whack if it isn't working") but it ran well and never failed to impress.
Gear used for review:
The CCT-1 proved to be fast, articulate, smooth and engaging. The match with the HD800 was particularly compelling. As reported by project86, the Yulong A18 + HD800 match is really good, but the CCT-1 + HD800 outclassed that combo in every way. The CCT-1 + HD800 was completely fatigue-free, detailed, powerful and just plain listenable. With every other phone I used, I was continually drawn into the music, to the point of losing track of time; I just wanted to keep on listening and listening.
Some raw notes:
- Fast, articulate bass
- No glare
- Great imaging and soundstage
- Vocals seem nice and warm
- True timbre, believable
- Full, almost tube-like
- Clear, great separation
- Precise - clinical but with still warm/appealing
I even had a full-on eargasm on Bjork's "Undo". Here's my notes from that moment: "Holycrap the heavens opened up and down came all of the angelic voices. Swirling holographic soundstage. Ooh la-la."
My weekend with the CCT-1 It was a very illuminating experience and all too short. I was impressed at how it could sound so rich, but also so true and natural. I am quite eager to watch it grow into a full-fledged product, if just so I can get some more listening time on one.
I believe Barry is intending to bring the CCT-1 to the Dallas Head-Fi meet June 1st, so if you have a chance, high-tail it on over to his table and give it a listen!
I spoke to Barry today and he reiterated that he plans to drive up for the event. FYI, this is the thread for the June Dallas meet:
noisyscott, out of curiosity, what are you using for a headphone stand? I like the looks of yours. With my new additions, I've officially got a little too much clutter on my desk.
No pictures necessary as I'm 99% sure it's the exact same item that noisyscott reviewed above. It had the same "love marks", tape residue, and other identifying marks that were visible in his pictures.
I'm a pretty open book. I like to think I'm pretty self-aware of my leanings and am pretty open with what I think they are.
My profile lists most(all?) of the gear I have and have had in the past.
For full disclosure, I made no promise to post this review, endorse this product, or pull any punches. I did not receive any monetary compensation, but I was the recipient of a large cup of coffee and a few interesting stories.
Scene of the crime
- Transport: Windows PC running foobar2000 using WASAPI(Event).
- DAC: Violectric V800 w/ USB and Sampling Rate set to "Best" (ASRC) and volume at 100%.
- Headphones: Audeze LCD-3(90% of my listening), LCD-XC(The remaining 10%), both connected via 1/4" single-ended headphone jacks.
- Comparison Amp: Violectric V200 with Pre-Gain set to -6db.
- Volume was level-matched by ear(read; imprecise) and was a tad past 9PM on the LCD-3 and a smidge below 9PM with the LCD-XC for both amps.
- While I usually don't leave the DAC on, the V800 and CCT-1 were both left on during the entire duration of my demo period of approximately
DISCLAIMER: Keep in mind that all listening notes came from a hand-built prototype over the course of 8 days (approx 6 just listening and then maybe 1-2 doing some A/Bing to confirm what I had already written down). I hesitated to post comments on the prototype since some of the comments are negative, but Barry convinced me that he was perfectly OK with my commentary: good, bad, or neutral.
- The sound is VERY clean. No bloom. No bass boominess. Quick precise attack with sharp decay.
- Brighter than the V200, but not overly bright. The V200 is considered to be in the range of neutral to slightly dark. I'd say the CCT-1 is fairly neutral.
- Highs are not fatiguing or harsh, despite being brighter than the V200.
- If the V200 is warm, the CCT-1 is definitly cool. I don't think anyone would mistake this for a syrupy tube amp.
- The snap of percussion is good.
- Cymbals sound clear to me.
- Snare drums and toms sound good.
- Kick drums are nice and tight, but sound thin. Slightly rolled off bass response?
- Soundstage was "good". DISCLAIMER: I find headphone soundstaging to be so inferior to my full range planars I don't generally spend much time thinking/feeling about it.
- Layering and separation of instruments was good.
- Has a very low-level, but audible noise floor with no signal content, where the V200 is dead silent. Barry seems to think this was likely due to the semi-haphazard part selection used for the prototype. No meticulously matched components to be found here (see noisyscott's pictures of the innards above).
- Electric guitars have a relaxed presentation. IMO, too relaxed. I did not enjoy listening to metal or rock on this amp. Did not induce toe tapping or head banging.
- Fast clean response on acoustic stringed instruments that is smooth, but perhaps overly smooth? There is no harshness or fatigue from "fake detail extraction" to be found. However, some of my bluegrass content has heavy plucking that seems to be stylistic intent. It's usually fairly forward, but the CCT-1 provides a more laid-back presentation that seems a bit smoothed over in terms of attack. All that said, I don't know if this is universally a bad thing. The detail crowd looking for "analytical" gear might not like this version of the amp. On the flipside, maybe this is exactly the synergistic amp that someone using an "analytical" headphone is looking for to get system balance.
- Umm. You saw the picture above. It's a prototype!
- The real thing could really use a better volume knob. Something with a touch more heft will go a long way in feeling solid.
- Piano sounds a bit thin/distant to my ears.
- On vocalists, Alison Krauss/Fiona Apple/Tori Amos, I don't get the "I am there" feeling. Presentation felt closer to being in a big empty auditorium vs an intimate club.
- Sibilance is a bit more present in some places than the V200. Ex. at ~45s mark of Fiona Apple's Shadowboxer: "And you ssset my sssoul at eassse". I'm probably exaggerating a bit here, but it was something I happened to notice.
- Sequence with repeated double kick drum hits on Metallica's The Four Horseman is supposed to sound like hoofbeats, but it doesn't have enough punch. I don't know if I'd call myself a basshead, but I do like deep punchy bass IF it's clean and tight. The album is "Kill Em All", not "Win the debate", so I'd like a touch more punch.
- French horns on Duel of the Fates seem to be missing something. I've always thought of the French Horn's presentation across multiple pieces of gear to be forward and impactful.
- Drums(bongos?) on Cuban Pete sound good and natural to me.
The CCT-1 is pretty impressive for something that looks like it was thrown together. While it has some flaws, I can get a pretty good idea of where this is headed, and I'm very interested in hearing the next iterations of this design. While it has a few fatal flaws in it's current incarnation, it's just a prototype! If they can iron out a few of the flaws, this will be a serious contender.
Questyle and Bakoon have gotten a lot of compliments for their "current-source" amps, and Nelson Pass seems to be pretty interested in designs with no global feedback. As such, this item seems buzzword compliant. I imagine Austin Audio Works will give them a run for their money when this gets closer to a production model.
Thanks again to Barry of Austin Audioworks for providing me with the opportunity to demo this gear.
Witness List(Track Listing) (Click to show)
10,000 Maniacs - MTV Unplugged
09. Like The Weather
Alison Krauss & Union Station - So Long So Wrong
01. So Long, So Wrong
07. It Doesn't Matter
10. Looking in the Eyes of Love
Fiona Apple - Tidal
Fiona Apple - When the Pawn
07. Fast As You Can
Stan Getz & João Gilberto - Getz/Gilberto
01. The Girl From Ipanema
Tori Amos - Little Earthquakes
03. Silent All These Years
Soundtrack - The Mambo Kings
1.05. Tito Puente - Cuban Pete
John Williams - Greatest Hits 1969-1999
2.12. Far and Away: Theme
2.14. Star Wars Episode 1: The Phantom Menace: Duel of the Fates
Foo Fighters - The Colour and the Shape
1.02. Monkey Wrench
1.07. My Hero
Megadeth - Rust in Peace
1.01. Holy Wars... The Punishment Due
Metallica - Kill 'Em All
01. Hit the Lights
02. The Four Horsemen
Metallica - Master of Puppets
02. Master of Puppets
Nirvana - Nevermind
Nirvana - In Utero
03. Heart-Shaped Box
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At Barry's request, I am reposting my May 25, 2014 review appearing here:
Over a period of multiple days, I had the privilege of auditioning the prototype of the "Austin Audioworks Thornton-Cohen CCT1" headphone amplifier. I paired it with both the Sony NC555ES and DVP-NS900V, fed by mostly well recorded and mastered SACD’s and a well recorded and mastered CD—Little Feat “Waiting for Columbus”—2 CD Rhino edition.
For comparison purposed, I ran my Woo WA-7 with the upgraded Electro Harmonix 6C45 tubes from these same decks. In fairness the WA-7 and its tubes had only a handful of hours at the time. I also ran comparisons with a Sony ACD-X540ES paired with an Audio-gd SA-31-SE, and an Oppo BDP-105 with a Quuestyle CMA 800R (which also had only a handful of hours of use at the time).
I tried many different headphones with the CCT1, including the following:
Sennheiser HD 650, 700 & 800
HiFiMan HE-500 & 6
Audeze LCD-2 & X (courtesy of Barry)
Beyerdynamic DT 880 (600 Ohm) & T1
Grado SR-60i & PS 1000
Although results with different headphones varied, I was very impressed by what I heard coming coming from this prototype headphone amp. The first can I tried with it was the former flagship DT 880. I had never heard that headphone sound so good. I could of sworn that I was listening to a can worthy of an almost $1,000 price tag. The “lowly” $79 SR-60i also sounded better than I have ever heard it or even imagined hearing from it. I concur with noisyscott (who also reviewed this prototype amp: http://www.head-fi.org/t/717046/austin-tx-amplifier-evaluation) that it is an excellent pairing with the HD 800. It is also a very fine mate with the HE-6. There were some headphones that, while I had no complaint with the pairing, seemed to be the rough equal of other quality parings. This was the case to my ears with the HD 650, HD 700 & PS 1000.
The areas in which I was most impressed about the CCT1 prototype (and it is just a prototype) included how it is able to bring out each musical voice without reducing the impact of the music.
Its sound stage was large and impressive.
The clarity, imaging and detail of its sound were outstanding and at the same time it was musical.
It had excellent extension, especially for bass—so much so that I heard quality bass that I had not before experienced from some cans (e.g. the DT 880 and SR-60).
It produced no harshness or sibilance to my ears.
I look forward to hearing the next step in the evolution of the CCT1. As I told Barry, I also look forward to trying it with the excellent but bass shy Shure SRH 1840 in my next session.