Preamp upgrade opinion...

Meant Pass XP10... not X10

I have a Pass X250. I used to have a MW SWL 9.0 SE and I really liked that pre but being singled ended was a little too noisy on the Pass. You're pass wants to run balanced so I would caution not sticking with a balanced preamp. I moved up to a MW LS36.5 and it's in another league honestly. The LS36.5 works and sounds great the X250.

I listen to much of the same types of music you do and the LS36.5 has great PRAT; pace, rhythm and timing. You can probably pick up a used one in your budget.

I came close to picking up a Pass X10 which gets great press in its price range and you can find them used at Reno Hi Fi in your price range. I went with the MW primarily because I really liked my SWL. Don't miss the SWL at all honestly as the LS36.5 is so much better.

Telos. No the ModWright does not at all lack bass. It's a great preamp that is not at all thin, overly tubey or a wimp. 

I spoke to Pass when I was looking for a new preamp and they strongly cautioned me using a singled ended preamp on the X250; I know on my former preamp it was too noisy. The X250 has 30dB of gain so it's a little noisy to begin with. They .5 and .8 series have had their gain dropped probably for that reason. They mentioned to me they ran it that high for home theater users to begin with.

I never had the XP10 at home but came close to trying it. Read a lot of reviews from actually users using it, also X250 and ModWright users and came across several here using the X250 with MW LS36.5 so I went that route and since my former preamp was a ModWright I felt safe and it is a great combination.

It is a fine preamp but like any tube pre, tubes make a difference and I am running none of the stock tubes which seriously made a great difference for the better.

Whatever you try or end up with I would stick with a balanced unit.