Balanced cables

The incoming mono tube amps are PrimaLuna HPs
Thanks

Balanced and single-ended (RCA) operations are inherently incompatible. So if RCAs are used its not balanced, and if the XLR outputs are used (and the preamp is properly balanced) then the use of the RCA connections will result in a buzz.

IOW its one or the other and never both, unless additional active circuitry is used.

The gain has nothing to do with it whatsoever. That is saying that to make something sound better, you just make it louder.

@atmasphere 

Are you able to expand on this further? I get buzzing if I use 2 sets of RCA cables with my standalone Phono stage. i.e. if I run RCA's from turntable into Phono and then I run RCA's into PreAmp I get buzzing. If I run Phono direct to Power Amps (phono has vol. control), no buzzing. Same if I go direct to Pre-Amp with inbuilt Phono no buzzing, but go standalone Phono into same Pre-Amp I get buzzing, so it appears two sets of RCA's from Phono sets off buzzing.

Thank you.

THEN (initforthemusic) if I use the XLR>RCA adaptors from the RCA output of the Krell preamp to the PrimaLuna amp's RCA inputs will all be OK?  I am using ;balanced cables.
Thanks upfront to all who help,
Dave

It might work okay, but I think i would be safer to buy a xlr to RCA transformer. Jensen makes a very nice one.
B

I get buzzing if I use 2 sets of RCA cables with my standalone Phono stage. i.e. if I run RCA's from turntable into Phono and then I run RCA's into PreAmp I get buzzing. If I run Phono direct to Power Amps (phono has vol. control), no buzzing. Same if I go direct to Pre-Amp with inbuilt Phono no buzzing, but go standalone Phono into same Pre-Amp I get buzzing, so it appears two sets of RCA's from Phono sets off buzzing.

@initforthemusic This sounds like you may have a ground loop between the phono preamp and the line stage. This is usually caused by poor circuit grounding practice.

To test for this, try installing a ground cheater adapter, which you can get at the hardware store, and use it to lift the power cord ground connection on first the phono section, and then also try the power cord ground connection on the line stage. My guess is the phono stage will be the culprit.

Please note that you should not run the system this way as such can be a shock or fire hazard should things go wrong. This is just for test.

if I use the XLR>RCA adaptors from the RCA output of the Krell preamp to the PrimaLuna amp's RCA inputs will all be OK?

Maybe. I would talk to Krell about this, otherwise if in doubt use a Jensen transformer as suggested.