New Tubes=Noisy Phono Section with VTL 2.5


I installed new tubes in the MC phono section of my VTL 2.5 preamp. Tubes are GE nos from 1963 purchased from Kevin at Upscale Audio.
When the preamp is on and only with the phono selected you can hear a some what loud hiss through the speakers. Could this be because of the higher Gain needed with the Moving Coil output?
With the CD selected the noise is barely audible.
I do not remember if the stock tubes were this noisy. I guess I could swap the original tubes with the new tubes ( when time permits ) to see if there is a difference. The sound when the music is playing is fine
I'm new to the "tube gear" so any help on this matter would be appreciated.
Thanks, Rick.
Ag insider logo xs@2xramond
The MC section will always be the crucial test for tube quietness because of the high gain level employed, but still, quieter tubes will = less noise. Did you specifically tell Kevin that these tubes were for an MC phono section? He should, IMO, offer to exchange these for something that will work better here - particularly if your stock tubes are indeed quieter - since that is what paying extra for careful tube testing/selection is all about. Often, only about 1 in 10 (or higher) individual examples of tubes commonly used in phono stages will be intrinsically quiet enough to give them preference in this application.
Yes they will be somewhat noisier than the high level section, regardless of the tubes used. This is the nature of high gain.
Thanks TWL on the quick response.
Any suggestions on a quieter tube for the phono section?
I almost bought the mullards but went with GE for the " sparkel" as Kevin described them in the top end.
Do you think basically all tubes will be some what noisy because of the high gain in the MC phono section?
Thanks again, Rick.
Yes, it is likely that the higher gain in the MC phono section could cause this hissing. Some tubes are quieter than others, and the very high gain in an MC phono stage will show all noise.