I recently purchased an SE84C-EX (an upgraded C from 2004 - equivalent to the CS, so I've been told) on audiogon.com and have noticed that there's a sea of background noise when the amp is just sitting there with the volume 1/4 of the way up.  Does anyone have any ideas as to (1) what might be causing this and (2) how I might alleviate it?

I'm currently trying out several pairs of output tubes (Ei EL84EG (Elite Gold), Russian 6P15P-EP, and Svetlana SV83), as well as a couple of rectifiers (Sovtek 5U4G and Sovtek 5Y3GT), but have not noticed any difference in noise production amongst them.

The one thing that I haven't swapped out is the input tube (a Sovtek 6992 which I'm waiting to replace with an Ei 6DJ8 Elite Gold)...and all of a sudden as I'm typing this I'm remembering an experience with noise and an offending input tube.

Maybe I just solved my own problem by talking through it, but if you guys have any other ideas please let me know.  Also, if you have any suggestions as far as tubes for this amp go, in general, let me know.

Thanks a ton for your time.

Well, after a closer "inspection," it's not the input tube at all...it's the phono pre.:

I hooked up my CD/DAC to it for the first time abuot 20 mins. ago and what to my wondering ears did appear?  A dead black background, completely devoid of noise!  Fantastic!!  So now how the heck do i solve my phono pre. issue?

It's Consonance PM-6 MM/MC pre. with a switch for MM and MC.  I guess the MC gain is relatively substantial becuase when I turn it to MM it's farely quiet, but when in MC mode it's a hiss-o-rama!

So, at this point I suppose I would like some suggestions on how to solve this issue (sheesh).

Thanks.

The Consonance is not tubed, so we're out of options in the "rolling" aspect.

I agree, the noise should be way in the background if at all existent.

Here are it's specs, in case they can be of any use:

CONTROL FUNCTIONS: Switch MM / MC
HARMONIC DISTORTION (for 2V RMS at output): 0.001%
INPUT IMPEDANCE: 47k ohms( MM ) , 3 ohm~800 ohm( MC )
INPUT GAIN: 40dB (MM ) / 60 dB ( MC)
OUTPUT INTERFACES: 1 group (RCA)
INPUT INTERFACES: 2 group (RCA)
GROUNDING INTERFACES: 1 group
SIGNAL/NOISE:90dB
CONSUMPTION:5watt
DIMENSIONS:200(L) x 98(W) x52(H) mm
WEIGHT: 4kg

Thanks.