PassX-250 vs PassX-350

I spoke to Peter at Pass and he helped me with some of the differences between the amps. The x150 and x250 have similar circuit designs with only some localized feedback around the output stage. The X350 and larger amps have the zero negative feedback characteristic which adds to their lushness and overall neutrality.

Nutella, that's new to me. I never heard the X150 and 250 use feedback while the larger ones don't. I do know, for a fact, all X amps employ a small amount of feedback in their supersymmetry circuits to help equalize distortion matching. As far as I have read, that's all.

Still, when I switched an X150 for X600 monos on 4 0hm speakers, I noticed more than the expected bass improvement. the midband was both warmer and it had more body. It is my guess the class A operation of the X600 accounted for the different performance. That is why I am voting for the X350 in Krelldog's case.

Bhouser, I am running $1500 speakers on $16,000 amps. If the speaker does everything you want, and it asks for the power, you feed it.

Muralman1,
I thought that was what I said. Rather, what Peter said.
For $4000 used I'd also opt for the X350

Good for you. Peter (right up the hill from me) might not like me saying this, but it's their fault - Pass Amps are so dependable, buying used is a safe bet.

Nutella, I agree with Muralman1 - news to me. In fact, my X-250 manual indicates the opposite, that both 250 & 350 use similar levels of (meaning Zero) feedback.

However, I certainly don't deny that the 350 is 'better' then a 250 in all aspects except the obvious one - the damn thing is TOO HEAVY !!! hehe.

So, if you can get one for $4000 (I paid $2800 for my 1-year-old 250), then I would say go for it. With the resale of your X-150, you are not expending too much jack. With the speakers you have, I guarantee you will not regret such a move.

Muralman1- I have taken care of my mental block of using 2k speaks with a 6k amp - I bought 7k speakers!! (there's no audio problem I know of that can't be fixed by spending more money ;^}.