Mods for a PS Audio HCA-2?

There's a gentleman that frequents both AA and Agon that has performed several different mods to his HCA-2. According to what he's stated, the amp responds very well to some basic mods. I'm sure he'll chime in once he sees this post. If not, i'll drop him an email and see if he can help you out. Sean
>

I modded mine (silver wire in output stage, Black Gate caps). There is more clarity in the mid and high frequencies.

I changed the output wire to solid silver in Teflon and replaced the cheap caps in the signal path to Black Gates. The difference will be immediate, but you will not fully appreciate the Black Gates for several hundred hours. It is not an exaggeration to say it doesn't sound anything like the stock amp anymore.

Everything is better. Especially dynamics and clarity. If you have the front-end to produce the piano properly, just wait till you hear the piano through an HCA-2 with Black Gates. The sustain and harmonics go on forever if they are in the recording.

In its stock form the bass was excellent with the HCA-2, but is seems even faster and tighter after the mods and the bass is surely more nuanced.

One more easy mod. Take the bolt out of the big transformer. Makes things smoother. Subtle, but noticeable.

Paired with the right speakers this amp is a steal with these simple mods. My speakers are 8 Ohm, 6 Ohm nominal, so take my comments with a grain of salt in relation to the load my speakers present.

As Sean will tell you, JA at Stereophile was disappointed with the measured results of the HCA-2 with a "test" 4 Ohm load. However, it seems the majority of owners of this amp don't "hear" JA's concerns. Same for the new Carver digital amp. Apparently it also measures like crap, but sounds wonderful as well. I personally can't say whether the HCA-2 sounds bad with a difficult load or not, but anecdotal information from several owners who have posted their experience with 4 Ohm loads don't seem to support JA's concerns. Having said that, I have read contrary posts from a couple of owners who thought the HCA-2 did have some problem with bigger loads. (However, the remarks from one of these owners has to be put into context. He is never happy with any equipment for very long before he is on to the next flavor of the month.) The point is, trust your ears. If you like this amp with your current setup, you will love it after these simple mods. For less than $75 this amp will take a huge leap forward.

BTW, I just recently received an email from a guy who did a blind shoot-out with the Odyssey Stratos and the HCA-2. Both the owner of the Stratos and the owner of the HCA-2 agreed the HCA-2 was better. The ironic point is that the Stratos owner was convinced he was listening to his amp (the Stratos) until it was revealed the amp in play was the HCA-2. Apparently he was stunned his Stratos lost. The only area where both parties thought the Stratos had an edge was in "detail".

Change the incredibly cheap stock caps in the HCA-2 and the wiring to solid silver and I am certain the HCA-2 will *easily* walk away from the Stratos in "detail".

I highly recommend these mods. They are cheap, simple and reversible.

Fiddler, I saw some mod packages listed here starting at $600, and adding $60, or even another $120, for a possible $820 total. It's not that this amount is out of the question, but I've been toying with the idea of bi-amping, so double that amount and add another HCA-2, and it's getting a little steep for me! You mentioned $75!!! Did you do the mods yourself?
I also have power hungry 4 ohm speakers, but the amp drives them pretty well so far. The reason for possibly bi-amping, is to try to improve the mid-range of my system with some different drivers and an active crossover
If you or Sean can let me know who does the work, and how much, then we can go from there.
Calanctus, You did the work yourself?