I experienced the same problem when I made the upgrade from Pass Labs monoblocks to Sim W-6 mono's. VTL sent me some 12AU7's to replace the original 12AX7's. This dropped the gain a lot and improved the sound quality overall significantly.
The gain is still higher than I would like but is more acceptable. Haven't heard about internal jumper changes.
I've never tried other tube brands since VTL explicitly states this will void their warranty. Don't understand their position, since going to some NOS Mullards, Telefunkens, RCA, Ampex, etc would most likely improve the sound quality over the stock Russian tubes which are about $20 each from VTL and can get a bit noisy over time especially with the gain problem.
Maybe the Mark II upgrade would lower the gain.
The 7.5 is designed to be mated with VTL's tube amps which have lower gain than many of the solid state amps on the market.
Great preamp with superb sound quality, design, and versatility.
The gain is still higher than I would like but is more acceptable. Haven't heard about internal jumper changes.
I've never tried other tube brands since VTL explicitly states this will void their warranty. Don't understand their position, since going to some NOS Mullards, Telefunkens, RCA, Ampex, etc would most likely improve the sound quality over the stock Russian tubes which are about $20 each from VTL and can get a bit noisy over time especially with the gain problem.
Maybe the Mark II upgrade would lower the gain.
The 7.5 is designed to be mated with VTL's tube amps which have lower gain than many of the solid state amps on the market.
Great preamp with superb sound quality, design, and versatility.