Purchased as a demo. I find this amp to be an excellent mate for Denon D7000.

REVIEW PS AUDIO GCHA
 
Paul McGowan is considered by many including myself to be a legend in the high end audio industry. Ps audio was founded in 1974 by Paul McGowan and Stan Warren who is no longer affiliated with the company. I have heard many of their 2 channel amplifiers over the years and was always impressed with their products so I decided to order a GCHA to see if would live up to my expectations for a reasonable 500.00 solid state amplifier for my LCD2 and Denon D7000. I was also confused as to why it has not been a best seller and is being discontinued.
 
Originally when this amp was released it was being sold for $1000.00 and that could have been some of the reasons why it did not fare well for PS Audio. I took delivery last week of the amplifier and used it without changing back to my reference Decware CSP-2 until the last couple of days to see how it compared. I had been using the Matrix M Stage as my only solid state amp and that was only being used to drive the Denon D7000 as my CSP-2 was used for my other cans. The GCHA was left on for the whole audition period and had close to 100 hours when I felt I was finished with my audition.
 
The GCHA is different than most solid state headphone amps as it has no gain adjustment switches but a new technology to adjust gain for each individual headphone called Gain Cell technology. The volume knob in itself serves as a gain adjustment and adjusts the gain so the amplifier is able to deliver the necessary power to properly drive the headphone it is playing. I noticed that most of the cans including the T1, LCD2 and the Denon were most comfortable between 12-1 o’clock.   The amp is said to put out 2W into the load and I found it very powerful and unstressed with all the headphones I used. It certainly had the power and finesse to make all headphones sound good whether it was the high impedance T1 or the more difficult to drive LCD2. The amplifier never clipped no matter how high the volume was on any of my headphones.
 
The shipping weight on the GCHA is 15 pounds and the build quality is the best I have has in any solid state amp I have heard to date. It certainly is built well beyond the bargain basement price it is currently selling for and in my opinion is as super buy for anyone who is the market for a powerful well built amp. The warranty if you register within 90 days is 5 years. The power cord itself supplied with the amp is very thick and solid and not a cheap cord thrown in. The amplifier runs warm to the touch and never was as hot as the Asgard. The bottom of the chassis was also warm as well. The front volume knob can be turned off and it allows for safe input and output of the headphones and the blue led turns off when the switch is turned down but the amp is still on.
 
The sound   I am about to describe would make most tube lovers enjoy this solid state design. It is slightly warm in signature with a very wide sound stage and also has great depth. The bass is present but not as tight as the Matrix. It is very refined and had a much better sound than both the Matrix and Asgard in my system. It s treble was rolled off. It was not as extended as I would have liked but never hard nor harsh. The amplifier always played jazz, pop and classical and did all in a very balanced and neutral presentation. The GCHA also had detail but not as good as my tube amp but on par with the Matrix and better than the Asgard. The sound stage was not as upfront as the Matrix. Sound stage was really very good as it presented the performers in their proper location and also was more laid back than upfront and in your face. The amp was better than the Matrix and Asgard by a wide margin in both refinement and sound stage presentation.
In the time I spent with the PS Audio GCHA I found very little not to like. It had good bass very detailed mid rang and slightly rolled off highs. In listening to large scale recordings it opened up the LCD2 with a very wide sound stage and had plenty of power on tap that it never congested. It had good bass but was softer than the Matrix in this regard so I felt in while being dynamic it lacked some of the speed and bass impact which the Matrix delivered in a smaller footprint but also was better with the slam I enjoy in solid state designs. The T1 played very well because the GCHA was able to produce the sound stage so well.  It also made me see where the treble was slightly rolled off. The Denon D7000 had much better synergy with the Matrix perhaps more because of the dynamics and bass slam the Matrix can deliver. Overall all headphones played well and the LCD2 and the T1 are a very good match for this amp.
 
In concluding I decided as much as I liked the GCHA it would not be a keeper for me. I am a hopeless tube addict and I prefer the sound of organic tube amps. The Decware outclassed the GCHA in pretty much dynamics, bass and treble extension. When I switched back to the CSP-2 I completely forgot about the gear and just enjoyed the music. So where does this put the GCHA. It is a very good amp for the money and it will drive every can I tried and do it well. If you are in the market for a 500.00 well built amp that has a non aggressive and musical tone this amp will please you. If you want more bass and more dynamic slam it will not be the answer. Overall for the current price it will provide years of enjoyment and also for many the satisfaction desired. For solid state lovers who want that less aggressive sound this amp is recommended. It also may be the last amp PS Audio develops for the head market so I recommend you take a listen if you’re in the market for an amp that is both musical and enjoyable.

I bought this amp used here on Head-Fi. I gave the value 5 stars only because you can now buy it new for $500. The amp is clean and detailed throughout the entire frequency range, and I am happy I bought it. Bass-heads should stay away from it, because it sides with depth and detail over quantity.