robmag,
I have played with a lot of amps over the years from ARC both tubes and SS, Krells ML, CJ, Aragon, McCormack, Parasound, PS Audio, Bryston, B&K, Forte and on and on... including the Counterpoint SA-220 mentioned above.
I currently own a X250 and don’t think you’re going to find a amp for $3500 that’s going to embarrass your Pass unless you’re not happy with it to begin with. I had a used X250.5 in my system for a few days that I should have jumped on but didn’t really feel was a huge improvement over my X250 but it was better. I have not heard the .8 but agree it’s a bigger jump money wise and the reason I haven’t made the jump but when ready will more than likely consider it. If your Dunlavy’s don’t require a big amp which once a Dunlavy owner myself I don’t think they require a big amp, look into a smaller Pass XA amp.
Without knowing your system I’d look at changing out the Dunlavys. I owned a pair for a short time and worked at a store that sold them so I’ve heard and know all the models. When the store I worked at picked them up they were the rage and I’ll admit I got sucked into the reviews and etc. and bought a pair, including their interconnects and speaker cables that were rolled off on the top - boring cables. The owner of the store was very kind to let me bring them back at no lose and I opted for ProAcs which I much preferred.
Sorry so long, but I think if you’re looking for a warmer sound then I’d look at other speakers and keep your X250. Another note; don’t buy what the owner manual says that power cables don’t make a difference... total rubbish - sorry Mr.Pass. I first started with a Kimber PK10 Gold and settled on a Wywires Silver Juice II which both cables nicely improved the X250 over the stock PC. My latest tweak which slightly, but did tighten up (defined) the bass was placing a hockey puck under the stock feet. I think I paid $2 a puck so if you think I’m nuts you’ll only be out 8 bucks if you don’t agree they work.
Good luck
