Mods for a PS Audio HCA-2?

Naunc, John Zurek from Positive-Feedback auditioned the HCA-2 paired with Thiel 3.6s and found them to be a good match.

http://www.positive-feedback.com/Issue9/hca2.htm

In fact he is now using the HCA-2 as his main amp.

As for Sean's comments, I and many others couldn't give a rat's tail whether the HCA-2 deserves a Class A rating or not (it has already been debated to death in this and other forums). If we were to all buy every "Class A" rating product we might as well be born with bar codes imprinted on our foreheads. Do you always judge everything by a rating? You shouldn't because it is your ears that is the ultimate judge. So if a professional reviewer uses this amp with a pair of power hungry speakers like the Thiel 3.6, does that mean his hearing is poor and he could not discern at all that the amp "was neither fast enough nor stable enough for me to consider it a worthy product." Obviously he found something he liked and so did I. I am currently using the HCA-2 to power a pair of Martin Logan Aerius i's which are well-known in audiophile circles to be voltage vampires. They make a good synergy as Fiddler would say. I have even hooked this up to my dad's Maggies 1.6s with stunning results. Lack of speed; not reliable- are you kidding me?

If the HCA-2 is lacking for Naunc, then perhaps he may have to re-evaluate his system set-up (speaker placement, room acoustics etc). By just removing the bolt from the transformer of the amp (a worthwhile tweak I read from others), the sound became much better. Tweaking is worth it for this amp. I mean for $1,695 how you can lose? You can buy a used one for a grand or less- tell me how many amps out there at that price can give such a high-end performance. Besides I have seen this amp drive difficult speakers with no problem at all and so contrary to Sean's opinion there are many others out there who feel that this amp has enough power.

Cheers,

Zen

Fiddler: Fast amplifiers have wide bandwidth, they don't ring just above the audio passband, they reproduce square waves easily, etc... This amplifier fails all of those tests as can be seen in the Stereophile test results of the HCA-2.

Having said that, a lot of people are fooled / confused into thinking that the system is "faster" by reducing the amount of sound that they hear. Less density to the sound, in tonal balance and / or harmonic structure, tend to make things sound cleaner and clearer i.e. add apparent speed due to the sound being less congested. Evidently, a lot of people that own or have heard the HCA-2 that think that the amp is "fast" don't know what they are listening to or for. What do i base this statement on? The Stereophile test results proved this amp to be "slow" beyond a reasonable doubt.

One can buy, use, listen to whatever they like. That is obviously everyone's individual option open to their own preferences. I'm not debating that some people will like how this amp sounds / interacts with specific components. The fact that this is a poorly designed amp, lacks speed, lacks stability, etc... has already been verified and is not really open to debate. At least not by anyone that understands how electronics work and can interpret test results. Sean
>

Sean, it appears that you are still obsessed with Stereophile ratings and tests. Although I would not go to the extent of calling this amp "fast", I cannot say that it is slow or lacks speed either. The Stereophile tests indicates "a lack of high-frequency linearity" but this is not all that uncommon for many amps. The main thing is that it does provide enough power to drive a large variety of speakers (not all- hence the qualification). To call it a "poorly designed amp" is a ludicrous and amatuerish statement. After all, if it was poorly designed, it wouldn't be able to drive my Aerius i's, Maggies 1.6. Thiels or countless other speakers even at high volumes. If it was poorly-designed it would break down easily, and the music would sound no better than being driven by a $100 receiver from Circuit City. If it was poorly designed, the whole technology of Class D and digital amplification is nothing but a scam and that companies such as Spectral, Bel Canto and others should just pack up their bags and throw away their digital amp models.

Why is it not open to debate? There are no hard fast rules to high-end audio. Anyone who "understands how electronics work and can interpret test results" also realize that the ears are the most important judges of sound. If it doesn't sound musical or good, then it doesn't matter what kind of specs are out there. It seems that you rely too much on specs and this is something you have to learn not to get caught up in. Specs are good- they tell us a certain level of performance that the electronics is expected to have but do not always indicate how the music will sound to "your" ears!

Here is a quote I have taken from Robert Harley's "Guide to High-End Audio":

"Many newcomers to high-performance music reproduction- and even a small fringe group of experienced audiophiles- question the need for listening to evaluate products. They believe that measurements can tell them everything they need to know about a product's performance. And since these measurements are purely "objective," why interject human subjectivity through critical listening?

The answer is that the common measurements in use today were created decades ago as design tools, not as descriptors of sound quality. The test data generated by a typical mix of auio measurements were never meant to be a representation of musical reality, only a rough guide when designing. For example, an amplifier circuit that had 1% harmonic distortion was probably better than one with 10% harmonic distortion. It doesn't follow that a harmonic distortion specification in any way describes the sound of that amplifier.

A second problem is that audio test-bench measurements attempt to quantify a variety of two-dimensional phenomena: how much distortion the product introduces, its frequency response, noise level, and other factors. Music listening is a three-dimensional experience that is much more complex than any set of numbers can hope to quantify. How can you reduce to a series of mathematical symbols the ability of one power amplifier, and not another, to make the hair on your arms stand up? Or the feeling that a vocalist is singing directly to you?

.....No matter how many measurements are gathered about the product's technical performance, they still don't tell you how well that product communicates the music. If I had to choose between two unknown CD players as my main source of music for the next five years, I'd rather have ten minutes with each player in the listening room than ten hours with each in the test lab. Today's measurements are crude tools that are inferior to the most powerful test instrument ever devised: the human brain" (Harley:p 34)

What is important to you- specs or the music? Are you an equipment lover or a music lover? Do you hear music or do you hear music as judged constantly on the performance of specs and latest technology. If it sounds good, it sounds good. Many tube amps have very poor ratings in terms of tech specs, but sound extremely good. Remember my friend, music like Harley points out is a three-dimensional experience.

The HCA-2 amp is not a flawed amp because it can successfully drive a number of speakers and the many owners of this amp are extremely happy with the result (the money-back guarantee by PS Audio is further proof that the company stands firmly behind its product and is not going anywhere anytime soon).

I read a lot of magazines and run audiophile forum, but at the end of the day, I trust my ears only. I have had my HCA-2 for 15 months now and not once was it broken or failed in any of my listening experience. I play this amp at least 4 hours continuous every day and it has never let me down- a flawed amp like you suggested will not be able to perform to not only my expectations but many others as well.

So give it up with the test results, the "square waves" etc (yes they are useful but do not give the final judgement on how the amp will sound) and just enjoy what you have without trying to put down a product based on specs. Using your own words: "I'm not debating that some people will like how this amp sounds / interacts with specific components" there shouldn't be any problems- am I not correct? No amp is perfect out there but hedck, if like you said, people like the sound of this amp then how can it possibly be "poorly designed"?

Remember as well, understanding "how electronics work" as you stated is not the same as understanding music and how music affects you. Before you start brandishing your comments on informing readers/contributors of this forum about the apparent flaws of this amp, try to gain a better perspective on the main thing that counts- learning to enjoy music and forgetting about the equipment. It is often the hardest thing for many audiophiles to overcome and is the greatest test they must pass. Trying not to change equipment every two months (controlling upgraditus) and listening with enjoyment is the real way to audio nirvana. Fiddler has the opportunity to buy an amp far costlier but still sticks to this- why? Because it gives him the greatest amount of enjoyment. Isn't that what high-end audio is about?

Cheers and happy listening!

Zen

I can spend a half an hour picking this amp apart in terms of why it is poorly designed and add links to where people found it to change sonics into different loudspeaker loads due to poor stability, but i'll just say "buy and use what you like". Sean
>

Sean, you said recently you have 20 amps, which I don't doubt. I would be very curious to hear what the top five are that you own.