Which preamp for a pass labs?

In your opinion, with a solid-stage preamplifier, is it more suitable for greater liveliness and dynamics?

No. Its not about tube or transistor, its about execution.

This is my opinion, but ARC is merely competent but never state of the art. Their circuits tend to be overly complex and have often left me scratching my head wondering why in the heck they did something the way they did as usually its pretty easy to spot areas in their schematics where performance has been left on the table, apparently with intention.

For example most of the ARC preamps now include differential input circuits, but every one I've seen has parts installed that actually reduce CMRR (Common Mode Rejection Ratio) because they limit the differential effect in the circuit! The more differential effect you have, the lower distortion, wider bandwidth and more gain you get.

This is part of why I asked earlier why the choice was limited to ARC or Pass. There are other tube preamps out there that are more suitable for driving a Pass Labs amp IMO/IME.

Which?

Like the OP, I use a Pass XA 30.5. My phono pre is a Pass XP-15 and my Pre is a Pass XP-10.  Even on the high gain setting on the phono pre, the system is very quiet, black backgrounds, I'm sure due, in a large part, to the balanced design and CMRR as Ralph points out.  The connection between the XP-10 and XA30.5 is a 25 foot run of Canare 4e6s star quad XLRs which sound exactly like a shorter run of AQ SKY balanced cables in my system.  This also agrees with Ralph's statement about the benefit of a balanced design and cheap cables.  

Hopefully some day I will sell the XP-10 and XP-15 for an Atma-sphere MP-1.

-Karl

VAC preamp with Purist balanced cables.