PassLabs 350.8 versus Ayre MXR Twenty

I found the Pass had a fuller, more musical sound and the Ayre comparatively leaner, perhaps owing to the bass coherence you cite.

I have found the same to be true.

However, which one would work best for the user would depend on his associated gear, and his musical tastes.
Many folks love the Ayre gear with warmer speakers like Vandy's.
Any speaker/room interface that might have a bit of bass bloat, may work better with the Ayre.

In the end, it's all about balancing a systems resolution and musicality to suit your own personal tastes.

@vindanpar, all Class A/B amps change sound characteristics when they transition from Class A to Class B. However, we're talking pretty high volume levels depending on your speaker sensitivity.  I wouldn't worry about it as you may never transition to Class B at your listening level.  The sound isn't bad, it's just a tad different.  Besides Pass Labs are a safe investment in this crazy hobby. They're easy to sell and hold their value if you keep it in good condition and save your packaging. Are you looking at new or a pre-owned 350.8?  For a pre-owned in good condition, you should expect to spend about $8k - $9k.

Maybe it's because you have speakers at the high end of the high end you heard the strain?

I have never had the opportunity to critically audition the Pass Labs 350.8 but did have an all night session with with the Ayre MXR-20, comparing to the PrimaLuna Dialogue HP, and VAC Phi 200s. After many hours of auditions, switching between Wilson Sophies, Quad ESL 988s and Vandersteen Quatros, Myself and fellow audiphile friend came to the same conclusion that on all speakers that we compared - the VAC, (especially running through the balanced outputs) had the largest deepest and most musical stage, while the Ayres had an impeccably clean, detailed, slightly dark character by comparison. The PrimaLuna fell someplace in the middle - but a bit short of both the Ayres and the VACs. While the Ayre MXR-20s are very, very impressive in terms of detail, imaging, dynamics and a dead silent background - I would not say their sound was particularly tube like. Got to agree with jmcgrogan2, the Ayres did sound incredible on the slightly warmer Vandies.
Jim

Not heard the mxr 20 in my system.  Never heard pass 350.8 but heard xs300.

i have the Boulder 2060 like cycles.  I understand what he means, turn up the volume and the Boulder expands the stage and moves objects towards you rather than just making everything a big amorphous stage. Kinda like you turning up the volume and it essentially remains the same.