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
najo
18 posts
 
You must swap tubes with some different ones! Start with the driver stage tubes (the small ones) . Then sub out the power tubes. Most problems will most likely be tubes. Sounds like the tube gets noisey(common) when warmed up.If you do not have extra tubes now is the time to get them. You will use them anyway if it is something else. Only after absolutely ruling out tubes is it time to look elsewere.
pops
2,272 posts
 
Sometimes swapping tubes (same tubes different channel) in a preamp solves that problem, it has to do with gain, not sure about power amps but worth a try. Good luck.
richardzerambo OP
15 posts
 
Hi everyone and thanks for the ideas so far. The unit is a Golden Tube Audio SE-40 and the noise is only in the right channel. I have been spending a lot of time trying to figure out what this noise can be so I have a lot of information about the noise. The best way to describe it is that it sounds like when you have a dirty volume control and every time you adjust it you get a loud crackling sound. I have timed the noise and it takes anywhere from 9 to 12 minutes for it to start from the time the amp is turned on. It continues until the amp is turned off. I have kept it on for 25 minutes to see if it would stop but it didn't. This noise happens without any input to the amplifier. The volume control on my preamp has no effect on the noise, the noise remains constant even at high volume. Once the noise has begun it happens intermittently with no set pattern but, there are no breaks in the noise except for the ten seconds or so between noises. From the responses so far looks like I had better get some new tubes.
puubie
45 posts
 
You may have a cold solder joint on the tube socket.

You might also try some fine grit sand paper and clean the tube pins.
rcprince
3,061 posts
 
I'm not sure how the Golden Tube is set up, but Najo is right, this sounds like it could be the small signal tubes, rather than the output tubes (the larger ones). Try turning off the unit and swapping the small signal tubes between channels (if there is a way to do this). If the noise switches channels, you have probably found your culprit. If not, turn off the unit again and swap the output tubes between channels, see if that does anything. If after swapping all tubes from one channel to another the noise doesn't move to the other channel, you probably have a problem inside the unit, and should contact the manufacturer. Good luck.
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