Amp Upgrade - 3k to 4k used?


Hi Folks:
I’m thinking of upgrading my amps and would value some advice. I currently have Blue Circle BC2 Monos. I’ve been really happy with them, but the upgrade bug is starting to bite again. I could spend about $3k to $4k on the used market. I’m particularly keen on tube amps (especially low powered SET), but not sure if my speakers would be efficient enough. I know my CD player is a little old too, but don’t think an upgrade here will get me a big bang for the buck. I’ll also consider upgrading IC and SC as well a little later on, but want really really good stuff (FIM or Valhalla likely). Another option may be to get a Shunyata Hydra. The rest of my system is:

Audio Physic Virgo II (89Db efficiency, I think)
Sonic Frontiers Line III – (but expecting delivery of Supratek Chardonnay in a month or so).
YBA CD 1a
Nordost SPM IC & OTA Sakura IC
OTA Sakura Speaker Cable
3 Shunyata Sidewinder Power Cords, 2 YBA Diamond Power Cords, 1 pair of Bybee IC Filters, FIM outlets.

All advice and recommendations welcome. Thanks,
John.
128x128outlier
Pass, Krell, Levinson, or BAT. Any1 of these maunfactures should make something that works well with the rest of your gear. Just bought a Line 1 and am very happy...how come your selling the Line 3?
I'm very happy with my Bat amps,especially
when I started changing out some tubes with
new old stock.
I don't think you could go wrong with a BAT, in particular there tube amps are super! Also worth looking into would be perhaps a Atma-Sphere otl amp of some sort, if I don't go from a VK-60 to a VK-75se I will get an Atma-Sphere and enjoy this OTL thing so many rave about. Which reminds me check out the Berning OTL(fake OTL but close enough) amps they are suppose to be giant killers for the money. ~Tim