Pass labs upgrade path

I think an XP22 is the best upgrade option. You will need to go to an XP32 to better it.

Depending on how much power you need, it's worth listening to the XA power amps before you upgrade your existing power amp. 

I was very happy with upgrade from XP20 to XP22, and X250.5 to X250.8...did not upgrade both at same time, but rest of system was same during both upgrades...have not heard the X350 series or the XP30...there also seem to be many who find the X250.8 different than the X350.8 but equally good...the high power XA amps are in my opinion way better...

Passive preamps take more than they give back. The Townshend is not passive, it uses a 12VDC wall wart, so what you are buying is an $8,000 volume control. And Pass XA25 is far from the best amp. Keep looking, and have fun.

I am running an Ayre K-1xe into my Pass X350.5 but the Ayre has too much gain and I'm rarely listening with the volume above 9:00. I was wondering if the Pass xp-22 is a sideways move at best from the Ayre since the K-1xe was a great preamp in its time. Can anyone comment on this comparison?

When I owned the XA60.8 followed by the XA160.8 paired with the XP20 I could not understand why two fantastic amps could be so underwhelming. I replaced the XP20 with the XP30 and still was far from impressed. Could it be the Pass preamps?! I inserted the XP30 into a friends system that consisted of an AR Reference 5SE paired to Parasound mono’s which at the time sounded great until I heard it with the XP20 and too fell flat and lifeless. Out went the Pass preamps and in went a tube preamp, in my case the original Aric Audio Motherlode tube preamp and then and only then, the big Pass amps sang with detail, richness, body and weight that the anemic Pass preamp failed to pull out.

Pass-great amps, not so great preamps, I am afraid. All of my fellow audio brethren who have convinced themselves that the Pass pre and amp pairings afford them the most ideal combination are, in my humble opinion, have been duped. Get a tube preamp!