Preamp suggestion for Quicksilver M120 amps

I doubt very much that will improve it. It’s just not your cup of tea. See if you can return it!

@agranttz 
Same scenario here on a 2019 Agon thread worth reading. It was a new QS linestage with no time on coupling caps or stock tubes.  Reported improvements over time from 20 to 200hrs. Then swapping out the stock lean sounding lower model JJ tubes with better vintage tubes.  

https://forum.audiogon.com/discussions/new-preamp-arrived?sort_order=asc

Thanks, I will not give up on QS just yet. Think I will connect a source to the pre and run it for several days, than put it back to compare.

Anybody can comment on how is Audible Illusions sound vs QS LS?

agranttz,
Update: today I swapped back and forth between my very best vintage 1960s Mullard 12AU7s and latest version PSVANE MKIIs in the QS Mono 120s. My buddy did the same in his Linestage last week, replaced the stock low grade JJs you have now. They do sound lean in our rigs too. Both of us gave the lower version JJs away. There are much better JJs up the line into the high $ Black Sable JJ versions but those are more costly than several vintage and 40% more cost than the new MKII PSVANEs which are decent for the $ if you don’t wanna mess with vintage.

Personally, I’ve tried the best from vintage 1960s Mullard, Tungsram, RCA, Sylvania, CIFT, Brimar, Amperex and more in my QS amps. Tried 17 different vintage pairs (some on loan) and 3 different new-reissues pairs in total. Same with my friend with the QS Linestage and QS Mid Monos. Both of us agreed, all so much better than the new low version JJs that came with your QS Linestage new-stock from Quicksilver. And, gotta say the new PSVANE MKII 12A?7 tubes are pretty nice too. Maybe a little fuller upper and lower midrange, maybe a tad more forward than my best Mullard "Blackburn" small signal tubes, but not bad ad all. With more burn-in they are settling back a tad more now. I like both, a lot. The Mullard vintage and the newer PSVANE are my #1a and #1b for different reasons. Have some of the latest "12AT7" PSVANE MKIIs coming this week to re-test those again too.

The QS Linestage and Mono amps are VERY responsive to replacement of quality small signal/driver tube changes, fwiw. And, with really great interconnects we noticed an even bigger difference with changes in the small signal and driver tubes. Hope this helps.

The pre responded to tube rolling, I like how it sounds. Still a question if it's better than Simaudio.

Need to address an issue with the power amps. Both produce a vary audible hum (big trannie on the left), can hear 60Hz from the speakers.

How do I clean up AC power? Balanced transformers? Isolated?

Thanks.