Noise Problem Conrad Johnson PV 12


A friend of mine just moved to Hong Kong and left me his Conrad Jonson PV12 with a pair of MB450 VTL. I do not know much about tubed preamps. I am experiencing noise from the CJ pre (tested VTL with other Pre amps and they are clean), if nothing is playing, cd player off, I hear mostly high frequency noise, white noise, some sputtering, even on both speakers, like a radio station not tuned correctly. The noise does not change levels if I move the volume knob up or down, it does change qualities if I change sources...cd/aux, etc. I emailed my friend and he wrote, "I swapped the original whinny tubes to a pair of Mullard CV 4003 and it pretty much killed the noise problem."...I am not experiencing a whinny sound at all. The CJ sounds incredible, but silence between tracks in not silence, and quiet is not quiet. Just this constant screen of white noise, loud enough to hear in a quiet room about 7 feet from a pair of Von Schweikert speakers.

Do most tube preamps have some sort of noise? Is this common with CJ equipment? Is there such thing as a silent tube preamp? I really like the moments of silence between tracks, pure black.

Help anyone?
anchorr

Showing 1 response by czbbcl

Yup its the tubes you need two 12au7's. This assumes that it is a line stage only (PV12al) and you don't replace the tubes for the phono stage if it has one (pv12a).

Chuck