Is the Pass Labs X350.5 and X1 "warm"?

Tony, with all due respect, if you don't hear much of a difference between a solid state preamp and amp and a tube preamp and hybrid amp, I don't know what to say. What recordings did you listen to? If you use some poorly recorded, compressed, canned sounding material, it is hard to make meaningful observations.

This was several years ago, so I don't remember all the equipment or recordings. I did use Sarah Vaughan Mercury Volume 4 Box set. These are good, but not outstanding recordings, that I know intimately and can listen around the average sonics. Sarah's vocals sounded anemic on the X1. The throb of her distinctive vibrato was almost absent on the X1, and the complex overtones and ring from the voice was reduced 50%. I also used Reference Recordings Dick Hyman Swing, which is a Big Band jazz disc. I remember the brass did not bloom out into the room, but sounded contained and smaller. Cymbals and high hats didn't ring out as freely or fully and didn't sound as natural. That's what I remember.

Kevziek, I may not have expressed myself clearly. I did not say there was no difference between the two; what I did say was that I could be happy with either one. Either has its strengths and weaknesses. Yes, they are different, but your description of the X1 midrange implies it is of a significant deficit in comparison to other high end preamps. I have not found this to be the case.

I actually listen to a lot of live music, and your point about cymbals and high hats is interesting. That's an area that I've paid some notice to on my system. Now I'll caveat everything with taking into account listening to a recording versus live, different acoustic space, et al, that the reproduction of things like cymbals and high hats now sound closer to the real thing (in my system) than before - in both tonal and spatial qualities.

I have tried the X1 preamp for few months and it was very good as far as soundstage, detail and low noise floor are concerned, harmonically things sounded right. Overall sound was neutral and refined and little dark but I would put it on par with all the really good ss preamps from Aire, Simaudio etc. The only thing I found was that musical drive and involvment were lacking a notch, things were a little dry in this area. Perhaps Pass amps compensate here (I used it with Krell FPB cx).