Mods for a PS Audio HCA-2?

Actually, Sean, it will only take a couple of minutes more to list all 20 amps that you have purchased or acquired on the basis of their performance.

I'm currently having another round of mods performed by Reference Audio Mods on my HCA-2 and will report back soon if possible. I've moved into smaller quarters and my listening room is so compromised I'm not sure I can make valid observations, but I'll report anything that I can on this subject.

It's been a while since I spoke with Kyle, who is doing the work at RAM, but I believe he's upgrading the digital power supply and some of the other more cost-effective mods that are remaining (I've done the easy ones already).

I just happened to stop by and was surprised to see this thread was still going. In reading the recent comments, I can find some truth in most of them. Certainly the stock components are far from optimial, and they are such an impediment to getting the most out of this amp that I can't comment on Sean's comments relating to inherent design deficiencies. They may in fact be there, but with so many other things getting in the way first, I don't feel like I've eliminated enough varialbes to say now I can evaluate the design. I'm hoping any design shortcomings will be more apparent when everything else has been upgraded. Until that time, the cheap caps, ringing power supply etc, make it hard to evaluate what's really inherent in the design itself. Of course, some of that is the design, so I'm not pretending it isn't.

I've posted a lot about this in the past but will say again- in stock trim, it's a heck of a deal at the price. However, IMHO, there's no way it's a Class A product stock (for those of you that care about those ratings, and even for those that don't). The important thing is that the mods I've made have resulted in such an overall improvement that I now thoroughly enjoy listneing to it, and as a result, don't spend much time anymore thinking about whether it's a Class A or not.

I'll report back anything I can when I pick up the HCA-2 with the latest upgrades.

Hi Guys,

I've never posted on audiogon but here goes. Firstly, sorry for digging up this old thread but i have recently purchased a demo model hca - 2 and imported to oz from the states.

I have read this thread from entirety and find it really interesting. I'm sure Fiddler was one of the people i contacted regarding mods to this amplifier, i've had so much advice i can't remember everybody's moniker.

Anyway, i was a bit disappointed with the sound of the stock amplifier to be perfectly honest. I have an aksa 100 nirvana plus amplifier and i thought the ps audio hca - 2 was better in some areas. However, where i was disappointed was the lack of inner detail/timbre, lack of dynamics and bass. The amp just didn't grab my attention and i thought it was boring.

After researching modifications i decided to have a tech friend install the 4 blackgate 100 uf 50 volt non polar caps in the signal path for me. They replace the cheap xicon 100 uf 35 volt caps which come stock with the amp.

Anyway i have about 20 hours on this amplifier and AFAIK it is a keeper. The dynamics are much better, the bass has improved (i'm satisfied with it) and importantly the inner clues/emotion of the amplifier is excellent. I had a really good time listening to the amp last night.

My tech friend did have a problem whilst installing the caps as the track lifted and he had to use a bypass wire to repair the damage. I guess what i'm saying is this mod isn't for a beginner.

My system is as follows:

marantz cd4000 (stock and cheap)
perpetual technologies p3a (modwright level 2)
N.e.w. p3 preamp (modified)
ps audio hca - 2 and aksa 100 nirvana plus
War audio speakers (raven 1 tweeter, mtm design, 2 x 7inch focal kevlar midbass drivers)
bluenote piccolo turntable
bugle phonostage.
bolder cables.

Best wishes

Rod