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

The X350.5 is indeed a warm amplifier. It may be one of the best out there in terms of combining the speed, detial and dynamics of solif state and the open, fluid and warm sound of tubes. Is it as warm and rich as a tube? No. But does it posess tube qualities? yes.

The X1 is dead neutral and I would think the combo would be a great match.

"The X1 is not a warm preamp. To my ears, it has a rather clinical and bare midrange that does not have a cohesiveness to it. Voices do not sound "whole", they sound pieced together."

Kevziek, I'm not sure I understand this. I've been using an X1 since the beginning of the year and find it hard to come to terms with what you've indicated. Been in the high end for well on 20 years, heard all the great stuff (and tried a lot of it in my own system), blah, blah, blah. My best friend uses the Full Function Quicksilver preamp, another FetValve hybrid amp, and the same speakers as me. Does his system produce a better midrange than mine? Hard to say. I could live happily with either system, but in comparison I would not call the X1's mids "clinical and bare". Could you relate the listening configuration that led to this assessment? Could you also recommend a piece of music that you used which pointed this out? I'd like very much to try it on my system.

Believe me, I'm not saying that the X1 is the greatest thing in the world - no piece of audio gear is. But IMO it's a pretty darned good preamp.

I am surprised to hear opinions about the Pass components on such opposite ends of the spectrum. I have read that the previous .0 version was a bit aggressive and lean sounding. I wonder if people are confusing the .0 and .5 versions? For those of you who say the Pass is not warm, can you please specify why model amp and preamp you are referring to? Can a Pass "expert" chime in and settle this debate?

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.