Pass Labs:What to expect fm XA60.5 to XA100.5

I agree with Onemug. Somehow, the XA200.5 sounds sweet, delicate, and holographic in addition to all the other things we associate with ample power. I suspect most other solid state amps sound hard and flat as a result of their more complex design.

Sounds like there may be no sonic price to be paid as you move up the Pass like, just the cash price (when you need the power).

In terms of the more power means more complex circuit with more stuff going on, so less good sound, that was certainly born our with the original Pass Amps, where the Aleph 3 was considered the best sounding, although very low on watts.

I'm going to be moving from an Aleph 5 to XA60.5 (I think) soon - I have Maggie 3.6s, so very hard to drive and damping factor means a lot in my case. I'm tempted to actively bi-amp and use Spectral or NuForce on low end. (Crossover is 225 Hz on Maggie 3.6), that is the only reason I'm not sure if I'm getting the XA60.5s. So, even if I'm still underpowered, it should be a massive difference from the Aleph 5, the XA60.5s have sooo many more Volts and Amps.

Overall I think I agree that a smaller Amp - *if* you have met your dynamic requirement - will sound better. In my case Maggie 3.6s seem to take any amount of power and still want more, so I am considering X350.5s too, and that might actually sound better in my case. Really take control of the bass panel...

Okay - this is my main comment. Add a Supratek or Joule-Electra pre-amp. With the rest of your system as it is, you'll be shocked by what happens! And then you will really have a system that plays with the big-boys :). I think it will be completely different than what you hear now.

Light,
Maggies are generally not a bad load for a good amp like Pass. IF the new 3.7s follow Magnepan pattern, there should be NO impedance dips to weird lows OR any huge phase angle stuff to deal with.
OTOH, they ARE fairly low sensitivity which is made up for by being dipole. Damping factor? Anything over maybe 20 will be fine. Even low damping tube amps work well, if enough power. The air damps the mylar pretty well, and being a single sided driver, not as coupled to the magnets as a good cone driver. The push/pull 20.1 may be slightly different.
You are right about dynamics and power, though...

Power users of panels like some of the big 'd' offerings. Spectron? massive.

Also, if Pass amps thru the line are anything like the XA 30.5, while it is 30x2 into 8, pure class 'a', the redline is almost 200x2into 4 in a/b. If the XA 60 does the same thing, it should be quite sufficient. Whoever said to look at the meter had it right. If the bias stays in 'a', or just a flicker periodically or on crescendos, than that is probably enough juice.

Given my listening habits (important for all to consider) I'd probably be quite happy with the XA30.5 level amp. The 60? WOW! OR if I had really deep pockets, a pair of 30s, as biamp!

Are the 3.7s fused? My 1.6s have a 4amp mid/tweet. I doubt the whole panel draws 8 amps at the limit. Thats just over 250 watts RMS..... How would that work out for dynamic power? Lots, I suspect.

Yeah - Spectron - that is what I meant when I said Spectral :).