Review: PS Audio HCA-2 Amplifier

Category: Amplifiers

There has been much said about this controversial amplifier, and I felt it was time that I offer my opinion of the piece.

Kalman Rubinson's glowing Stereophile review of the HCA-2 was much talked about, as John Atkinson's accompanying measurements were far from flattering to the amplifier. This resulted in much heated debate about the amp between two rather polarized groups -- those praising the amp and those trashing it.

I must admit that I was rather skeptical after seeing the measurements, but there was so much good said about this amp, that I suspected the old adage of "measurements don't correlate with sound" was a distinct possibility here. I had to try one for myself.

Using the HCA-2 certainly convinced me to throw measurements out the window. Listen to a piece with your own ears, and don't get caught up in the measurements. They often mean very little.

Do also give this amplifier a good 100 hours of burn-in time before serious evaluating it. Initially, it is a bit thin, the bass is too damped, and it is slightly harsh. When I see these amps for sale, the ads often say, "used 10 hours", or "used 40 hours." I don't think these owners really gave the amp a chance, and that's why they are selling.

Upon placing the HCA-2 in my system, it was immediately apparent to me that this was a very detailed amplifier. Details not heard before were suddenly there. Details that were somewhat obscure were now much clearer. I quickly determined these were not over-etched or due to brightness or treble lift. There was simply more information to be heard.

Probably related to this was the lack of grain or texture that I heard in all the solid state amps I had owned or auditioned. I need to point out that I have not heard many of the transistor offerings out there, so my experience is limited to those amps I listed.

Suffice it to say, there was less of a solid state "sound" to the presentation. Instruments had more of the bloom associated with tubes, and were not as flat sounding as they were with other SS amps.

The HCA-2 presents a wide and large soundstage with sufficient depth, but I did not find the cavernous depth that some have described it as having. My tastes run towards a very slightly "present" sound, as opposed to a recessed or distant sound. Similarly, I did not find the HCA-2 to be very forward, although it certainly is not retiring. There is a cleanness and freedom from grit or texture that transistors often have.

Voices had a good focus and body. Percussive instruments, such as cymbals, brushes and guitars, had a clarity and detail that was very clean. There was perhaps a bit of brightness somewhere in the lower treble, but less objectionable than I have experienced with other transistor amps.

The bass was the area that I would have liked more punch and body. Although tight and defined, I found that it did not give the fullness I need with my very linear B&Ws. I had sold my Audio Research VT-100, for no rational reason other than audiophile neurosis, right around the time I got the HCA-2. After several months of using the HCA-2, I had the opportunity to buy another VT-100, and I did so.

Placing the VT-100 in the system returned that fuller sound to the bass. This swap also demonstrated to me that the PS' lower midrange was not as full or present as the VT-100. But we need to remember that we are talking tubes here. My VT-100 also is fitted with Svetlana KT-88's, which give a fuller upper bass and midrange compared to the stock tubes. The VT-100 was not quite as detailed as the HCA-2, but in the end, I preferred the sound of the VT-100.

One must keep in mind here that I am comparing a truly great tube amp with this little PS. For me to compare these amps and say that I could easily live with the PS if I did not have the VT-100 is high praise indeed. No other solid state amp that I had in my system gave me as much musical satisfaction as the HCA-2. I found every other solid state amp to sound undimensional and possess a certain "deadness" to the sound. I did not find these nagging qualities to the sound of the HCA-2. It is as close to doing what a tube amp does as I have personally heard. No, it still doesn't have the body of a tube amp. It still doesn't sound as "there" there. But it is much closer than other SS amps. Most importantly, it has a realness and aliveness to the sound that many solid state amps lack. I would guess that it would be a fantastic match with a Vandersteen or a slightly warm speaker. The fact that my B&W's are not warm, but more on the analytical side, and they still sounded quite good with the PS is high praise indeed.

Tubes, to these ears, still reproduce music in a way that eludes solid state, and I will still use tubes for my primary amplification. However, at a retail of $1,695, the HCA-2 has a lot going for it, and it is a little gem of an amp.

Associated gear
Rogue Magnum 99 preamp, Pioneer PD65, Bel Canto DAC 2, B&W 802 Matrix III w/Northcreek Crossovers

Similar products
McCormack DNA-225 & DNA-1 Rev. A, Classe CA-201, Audio Research VT-100 Mk II
What were your thoughts on the McCormack DNA 225 and Classe CA201? Thanks.

If you re-read Kal's "rave", it's not really a rave. Kal also publicly stated that he had nothing to do with this amp being placed into Stereophile's "Class A" category as this was already decided prior to him receiving the amp for review. The "Class A" rating was based on Sam Tellig's "review" according to what JA stated in prior threads pertaining to this unit. Either way, it is like any other unit. If it works good within the confines of your system and you like the characteristics that it brings with it, enjoy it. Sean
The DNA-225 was a good sounding amp, but complex orchestral or bank passages sounded slightly compressed. Instruments seemed to get pushed together, lacking the separation of lines they should have had. It was not a bright amplifier at all ( a good thing). Take all this with the caveat that I only used the DNA-225 for 50 hours, so it was perhaps not fully broken in.

The Classe 201 was a pleasant sounding amplifier with a warmer and fuller midrange than the DNA-225, but it also seemed to compress dynamics and run instruments together even more than the McCormack. In the end, I felt it had a somewhat "homogenous" sound, with a sameness to its sound.
Sean, I don't agree that it is "like any other unit." In particular, as I stated, it really doesn't have some of what I deem to be "solid state sound" characteristics, which is a big plus. More body and less "flatness" than other transistor jobbers I've heard.
I meant that it is "like any other unit" in the fact that it will either mesh with a system or it won't. I wasn't implying that it had "no special traits" as the amp has several measurable traits that might / might not benefit a specific system. Sean
Kevziek, thanks for an interesting and informative review. I'm glad you took the time to break in the amp and compared it to other well-known products that you have heard.

Re the KR review: well, I guess that writing all those papers in grad school dumbed me down so much that I can't read plain English anymore, and that what certainly seemed like a glowing review (just as Kevziek states) was actually not... :)).
I guess we have different ideas as to what a "glowing review" is. When a reviewer goes out of their way, albeit a couple of times, to make sure that one fully understands that a product has a distinctly coloured presentation compared to several other amps on hand, i don't call that "glowing". "Glowing" to me is a full tilt endorsement with no reservations or noticeable flaws to the point that the reviewer feels the need to harp on them. Granted, the majority of products reviewed in Stereophile all get "endorsements" and "glowing reviews", but some are much stronger than others. Sean
There are so many amps out there, so I would not be surprised if there are transistor amps that do not have a "silicon" sound. I can only say that those I have experience with lack the sonic attributes that tubes provide. The PS is not perfect -- and nothing is. But to my ears, it provides some of the palpability and body that a tube unit provides, and it doesn't seem to get confused when the music becomes complex, which is something I found in nearly every conventional solid state amp I listened to.

When I have the resources, some possible contenders I'd like to try would be: Pass, Gamut, Clayton & Plinius, among others.

I stand corrected - KR didn't give the HCA-2 a rave review. But he was quite impressed with it, and told anyone looking for a new amp to consider it, especially considering THE PRICE, price being the key word. I basically concur with his analysis of the amp, with the exception of his perception of depth being huge, I only perceived as above average.
I compared over twelve SS amps last year and one of them was the Spectron Musician digital amp. It was very fast and extremely clean sounding but it sounded like the music was coming from one plane without the depth I wanted. Also my older Kinergetics KBA-75 was more musical sounding. I bought the Pass X-250 which is not as clear sounding but had other characteristics that I liked. The digiatal amps are not bad for the prices since the Pass lists for $2500 more.
Bigkidz, what are the qualities of the X-250 that led you to buy it over all the other amps you auditioned?
Kevziek: Not to steal Bigkidz thunder, but you really have to listen to a Pass amp in a well set-up system to be able to understand what they sound like / do for music reproduction. I think of them as bringing the "three E's" to a system i.e. Engaging, Engulfing and Emotional. Until you hear amps of this calibre, you really don't know what you are missing. Sean
I listened to this amp and put more than 100 hrs on one. My real criticisms and are that like the thread going through other reviews is thatit has to be mated to the right set-up. It does not work well with some loads.
this amp is brand new and it sounds great right out of the
box, cant wait till it breaks in. my system is hca, wadia
301, legacy focus 2020s......