Pass Then vs. Pass Now

@jjss49 Thanks !  As you've said, Nelsons' First-Watt "kitchen-table" amplifiers were designed for sounding terrific from the first-watt in mind.  The reliability also of the Pass-Labs and First-Watt electronics is well-known.  Nelson is also one designer who is very willing to share design information and I've e-mailed him questions about my amps on several occasions.  He's always gotten back to me and rather quickly, considering he must be a pretty busy man.  I love the minimalist approach to the First-Watt series and the sound of very few active components "singing" through a fairly efficient speaker can be captivating.  It was that way with the SIT-2 and my Volti Vittora's.and even my Living-Voice OBX-RW's. The Vittora's are long-gone as there was no room for them in our retirement cottages' small listening space, however the 106-db single driver speakers are coming soon ! Happy listening !

I’ve heard the first watt, it’s an amazing amp, the x25 is on onother league, musically dynamic.

Great discussion everyone. Really appreciate all the feedback and lively back and forth. 

@liquidsound you raise a great question. Being that I live in an apartment I can't really play too loudly. In fact one of the reasons I am looking to upgrade aside from a general improvement is that I find I need to turn the Sphinx up considerably before there is any weight and dynamics to the music so I am hoping to achieve a fuller sound at lower volumes.

@audphile1 I am glad you brought up the Audio Research LS-25 and Ref1 preamps in combo with the pass amp. Although I am not ready to purchase a new pre yet, I have started to look around and aside from the obvious pairing with an XP-12 I was gravitating towards the AR Ref 3. I also read some really thought provoking reviews of Shindo Labs pre amps but those might be just out of my reach price-wise and difficult to find as well. 

@twoleftears

in my 17x20 room, i have a listening triangle roughly 11 ft equilateral, i don’t listen real loud, rarely exceed mid 80’s db peak loudness

in that context, with my mon 40’s all pass amps drove the speakers very satisfying for my listening... bass control is also excellent... i had an f6 for a time, felt that one was maybe just a touch loose gripping the woofers... my f5 is modded with extra power supply capacity (bear in mind the f5/f6 are push pull amps, not single ended as most lower powered fw amps are) so that one does fine too, xa25 xa30.5 and up all sound effortless

parenthetically, i would say my favorite for driving the mon 40’s is the linear tube audio zotl40 reference, with a pair of rel subs augmenting the deep bass crossed over very low.... that is a hella sweet combo... clarity, purity, vast spaciousness, excellent impact and of course, the midrange magic in spades...

hope that helps

FYI. I used to own a Pass preamp and amp… and found the Audio Research preamp and Pass amp to be the preferable combination. The ARC has a better midrange bloom… more natural and fleshed out. It really is ARC’s thing… preamps.