Thanks for the suggestions. I should have remembered to specify a budget.
The XP-30 and Ref 5SE are out of range for me - even the the XP-20 is pushing things a bit. I auditioned an ARC LS-27 and liked it but that was with an MC-452 before I purchased the X250.5, I suspect it would work well with the Pass and the REF 5 suggestion backs that thought up. The other pre I tested was a friends W4S STP-SE which was surprisingly close to the LS-27 as far as tone. I may have to ask him to dismember his system again so I can try it with the X250.5. Oh the budget - prefer to stay less than 5K, but could stretch to 6.5 if pushed.
Thanks again.