2. amps-preamps
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Any way to reduce pre-amp noise floor?

I have had my CJ ET3-SE tubed pre-amp for about a year now. When my system (McCormack DNA 500 amp, Esoteric X-05 CD, Aerial 10T speakers) is on and the CJ is set to "0" volume there is dead silence. However once I move the volume to to any level above zero ( no music playing, of course!) I hear a very soft but audible white noise. When I return the volume to zero the noise vanishes. This concerns me because I suspect that once the music begins to play, this noise floor becomes part of the overall sound.

This is my first "separates" system so I'm not sure if this is just a standard preamp phenomanon or if it is perhaps a sonic signature of CJ or if there is some real issue that needs to be fixed or can be tweaked. Any comments/suggestions will be greatly appreciated.
shoff
onhwy61's avatar
onhwy61
5,196 posts
 
Exactly how loud is the noise? Is it only audible when you place your ear next to to the tweeter dome or is it clearly heard at the listening position? Does it get progressively worse as you raise the volume control setting or stays the same? Have you ever heard the noise when music is playing?

It could be the normal sound floor of your electronics. It could be the sound of a noisy tube. It could be noise coming in over the power line. Answering the above questions will help narrow the possibilities.
mechans
3,048 posts
 
My first thought was a tube issue as well. Tubes are frequently noisier than SS. In a pre-amp, any tube in the signal path and especially in a gain stage, should be very carefully selected for low noise. Even then, as tubes age, they can develop noise problems.
I find the tube sonic so appealing, that I am willing to sacrifice a very, very low noise floor. If it isn't audible with music playing you might want to live with it.
elescher's avatar
elescher
114 posts
 
Look into improving the grounding on your system.
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