Parasound HCA-3500, Am I Crazy?


Hello to all,
I recently borrowed a friends Parasound HCA-3500 power amp just for the heck of it. [I was always curious how this amp sounded].
I unhooked my Parasound Halo JC-1's and hooked up the Parasound HCA-3500 in its place.
Much to my shock, there were some things that the 3500 seemed to do better than the JC-1's in my system:
The HCA-3500 actually sounded more transparent, open, and more extended on top than the JC-1's! This was especially true at lower volume levels.
The HCA-3500 also seemed to have a deeper soundstage, and a blacker background.
The JC-1's seemed superior in most other regards, however.
The JC-1's sounded smoother, cleaner, had slightly more body, more detail, and better bass control than the 3500.
The 3500 did sound a touch etched and slightly grainy, but it sure sounded damn clear, open, and transparent!
How could this be?
Anyone else out there experienced this?
Break-in is not an issue. My JC-1's have close to 1,800 hours on them.
I am just puzzled folks, thats all.
audio_girl
audio_girl
Has anyone had the chance to compare the JC-1 vs HCA-3500
after Steve (Empircal Audio) has done mods to both?
I've not compared the two but am on my second HCA 3500 after trying a Marsh A400s in between. On my VMPS Rm 40's which are extremely transparent I find the 3500 performs excellently from the bottom to the top. This in contrast to the Marsh A400s which is also a good amp and I think it was REG of Absolute Sound who claimed it to be as good as anything upto 20k. The Marsh did have some good qualities but overall I went back to the 3500. It seems to do everything right and with ease. My pre is an ARC LS 16. My room is dedicated LEDE with bass traps. If there's any serious shortcomings it doesn't get in the way of the music.
Audio_girl,

Excuse me, but since I don't know you or your experience level, I have to ask:

Did you use all the same power cords, interconnects, and speaker cables when you performed your evaluation? Or, did you try different things to try to optimize the performance of each amp? Were they plugged into the same AC line? Through an AC conditioner or not? Did they use the same mechanical-coupling methods or vibration control? Heck, I've heard some gear sound appreciably different just by setting the component on a different surface or by using different footers.

On the surface, one would think that performing the evaluation keeping everything exactly the same would be the fairest possible methodology. In my experience I have found that this is not always to be taken for granted.

These days, when I make such comparisons, I try to optimize the installation for each amp (or other component) so that each piece will sound as good as I can possibly tweak it to sound. What works best for Amp A may put amp B at a disadvantage (and vice-versa). So what, on the surface, would appear to be an impartial evaluation or observation, may be (unintentionally) slanted due to factors that simply may not have been considered. Your comments about the 3500 sounding "grainy" or "etched" might be right on the money -- but they could also be telling you that the 3500 does not like the same cabling or footers (or whatever) that work well for the JC-1's.

If you haven't had the amp to play with and tweak over a period of time then you probably have not heard it at its best. Brief shootouts can be misleading. Extended evaluations over time are more reliable indicators.

I don't own either amp you're speaking of, so I have no stake in the outcome one way or the other. But I do like to see things done fairly and competently. For sure, there are a lot of variables to consider.

It's just food for thought...
Plato,
I have extensive experience setting up gear for comparisons.
I am still borrowing and using my friends Parasound 3500 as we speak. He did say that he had removed the stock Vishay 47K feed-back resistors and replaced them with Holco 47K ones. He said this was the only deviation from the stock units.
I have tried various cables and vibration control devices on both amps, and the results are basically the same. I use dual dedicated lines for the amps. I use a Shunyata Research Hydra 8 power distribution device as well.
I also tried out an Adcom GFP-750 preamp with the HCA-3500, and it matches up really well with it! Actually the 3500 sounds better with the Adcom than it does with my Ayre preamp! Low volume detail, transparency, and openness is remarkable with this combo. It is great at higher levels as well, but really shines at lower volume levels.
While I overall prefer the OVERALL sound of the JC-1's, the 3500 is remarkably clear, transparent, and has extremely extended highs. It also have remarkable image depth. Again, the main drawbacks are a slight etch and some slight grain on certain cd's. LP's sound marvelous on the 3500.
Audio girl, the HCA 3500 has a ton of 2nd harmonic distortion compared to the JC-1 and that is probably what you like and dislike about the 3500........I changed out a couple of mosfets and the 2nd harmonic dropped dramatically and the two amps sounded quite a bit more like each other with the JC-1 being a significantly better amplifier for long term listening.......faster, cleaner and things that a better layout will allow in the JC-1...........The etched sound of the HCA3500 sure can be addictive as several folks have reported liking the old war horse better than the JC-1s, but once the 2nd harmonic is reduced it can become a much better amplifier........