Bat VK-P10 and Sonic Frontiers SFP 1 Signature

I have a VKP10. I'd never describe it the way you are. I am running it with a VK50SE preamp. I'd send Victor a email or call BAT. Maybe something is up with yours. Bad tubes, cartridge mismatch, cap, gain, or resistance set way off. Hard to tell, bet you should be happier than what you are. Read the reviews on Balanced.com. Even with single ended gear the p10 is loved.

Some other good advice above...

The problem existed with both a Clearaudio and a Koetsu. In actuality it also exhibited a ground hum with the Clearaudio that only was there in the balanced mode. I switched back to an RCA phono cable and solved that problem. BAT acknowledged the issue with Clearaudio cartridges and earlier VKK-P10 that did not have truely balanced inputs. They did not offer to remedy the problem. The noise I am now referring to is an amplifiable hiss that is more of a problem with both jazz and classsical music. The preamp has been moved to isolated locations that would preclude other equipment from being the cause. As stated, the Sonic Frontiers Signature costing one third the price and also a tube preamp is much quieter.

i've never looked inside the bat units and also wonder if BAT makes tru-balanced design especially on units where both options are available.

the Bats are truly balanced...

I'd go to a good solid state front end or a transformer for low output MC cartridges, especially if you are using a tube ine preamp. I use an updated Pass Ono. The Ono has a true balanced output as does its follow on X ono and sounds great single-ended or balanced. BTW, I am not anti tube, I just received my Wolcotts and they are wonderful and quiet as "the proverbial tomb."