Carver Raven 350 Amps

erichgs,

Yes dead quite. If there is any noise I can't hear it. 
BTW, I also placed rca non shorting caps on the rca inputs. Perhaps that's what took it to zero noise.
Everything matters...

Now to experiment with input tubes...

ozzy

The Benchmark DAC3 has jumpers to attenuate the XLR output.  I moved the jumpers from the default position (0db) to the middle setting (-10db) and now I am noise free as well.

OZZY, where did you buy those rca caps

erichgs,

I have moved my jumper and output settings on my DEQX premate to its highest output settings and still no hum. 
I can't tell you how satisfying it is to have discovered the source of the hiss. It was amazing that I missed something so obvious for a week.

smokenjo,

They can be purchased from  many places. I bought mine off of EBay from a guy located in Michigan, they are of  very high quality and with fast delivery. Now remember these are caps not shorting plugs. I have used them on all of my unused rca and xlr input/output throughout my system.

ozzy 

what is the diff.  between a RCA cap and  RCA shorting plug