2. amps-preamps
  3. 983821701

Tube amp blues

I'm sure that there is a simple explanation but being new to tubes I just haven 't learned it yet. When I turn on the amp it starts with no problem and plays wonderfully. After about 3 - 5 minutes it starts making a "static-y" sound from the right channel. This is not constant, it comes and goes about every 10 to 30 seconds and there sometimes is white noise between the louder static-y sounds. Both sounds (Static and white noise) come at different levels sometimes louder than others. Sometimes there is no "static-y" sound at all and all is quiet, just great sounding music. I have done some checking and this sound does not respond to any of the other equiptment. Only the amp needs to be on for it to happen. When the whole system is on there is no difference in the noise. I have played music from my CD and Turntable at different volumes and the noise is not affected. I have found nothing that can be done to stop the sound or make it worse except turn off the amp. It only starts after the amp is warmed up. Could this be a bad tube? Or a bad component on the board that is causing this after the amp warms up? Any Idea's.

Thanks Rick
richardzerambo
david99
1,467 posts
 
I had a similar problem last week.I have a tube pre and SS amp.I was getting (L) channel noise just like you described.I put the (L) channel line-stage tubes in the (R) side and (R) channel tubes in the (L) no more noise.Sometimes just re-seating the tubes and/or cleaning the pins is all it takes.
richardzerambo OP
15 posts
 
Thank you so much for all of the ideas. I switched the driver stage tubes and the noise magically went away. This is great! the amp sounds great and I spent the rest of the night listening to it. This is a really great site, especially for a newcomer (to this site and to tube/analog audio). I have posted several times with problems and each time was given good advice from alot of people. At first I was hesitant to post but I'm glad I did. Again I want to thank everyone for your response and suggestions.
Rick Zerambo (Reading, PA)
finfinder
73 posts
 
One of the best things about the se40 was that it used cheap tubes. The sovtek 5881's can still be had for about 10 bucks each. The driver tubes are the ones where it got a little more expensive but there were only two per amp. I would switch all the tubes from one amp to the other. If the noise goes to the other amp then replace all the tubes in that amp.
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