#1
my amp crackles when i turn it on. i thought it was my preamp tubes so i went and bought new ones, the crackle remains. could it be my power tubes? i recorded it, check the link:

audio sample
#2
Sounds like interference to me. Try tapping your power tubes with an eraser. If you hear the tapping through your amp, it's time to replace the tubes.
#3
Quote by nick.culliton
Sounds like interference to me. Try tapping your power tubes with an eraser. If you hear the tapping through your amp, it's time to replace the tubes.

That only works for testing microphonic tubes.
#4
My amp does that occasionally, but it's not when I turn it on -- it's completely random.

I simply ignore it, since all the tubes are new and apparently there's nothing wrong.
#5
Wow, that's a really good song. I like when it cracks, that was the best part!
#6
Quote by Linkerman
My amp does that occasionally, but it's not when I turn it on -- it's completely random.

I simply ignore it, since all the tubes are new and apparently there's nothing wrong.

I just replaced all my tubes a couple at a time. First I replaced 2 preamp tubes, then power tubes (mine has 2) and 1 more preamp tube, then finally the last two preamp tubes. I was trying to cheap out. Can't go wrong with a new set. Then you can blame noise on your cords and pedals or whatever.
#9
Sometimes that is the sound of dirty/corroded tube sockets. You can pull each tube (amp unplugged), spray the pins with contact cleaner and work them in and out of the tube socket a few times. Then wait an hour or so for the contact cleaner to dry up before plugging the amp back in. This will sometimes solve it. If no joy, find a music store nearby with a tube tester and take them in. If the tubes are bad you will know for sure.

I replaced a set of tubes recently and one of the brand new JJ preamp tubes was bad out of the box. Annoying but not tragic. I just used one of the old ones I kept as a spare and the amp sounds great again.

Remember too that depending on your amp model, replacing power tubes may not be plug-and-play so you may need to re-bias. Not a job for the casual DIYer.
Last edited by Cajundaddy at Nov 9, 2014,
#10
Quote by Cajundaddy
Sometimes that is the sound of dirty/corroded tube sockets. You can pull each tube (amp unplugged), spray the pins with contact cleaner and work them in and out of the tube socket a few times. Then wait an hour or so for the contact cleaner to dry up before plugging the amp back in. This will sometimes solve it. If no joy, find a music store nearby with a tube tester and take them in. If the tubes are bad you will know for sure.

I replaced a set of tubes recently and one of the brand new JJ preamp tubes was bad out of the box. Annoying but not tragic. I just used one of the old ones I kept as a spare and the amp sounds great again.

Remember too that depending on your amp model, replacing power tubes may not be plug-and-play so you may need to re-bias. Not a job for the casual DIYer.

do you mean spray the contact pins of the pre or power amp tubes?

i replaced my preamp tubes because i heard this crackle, and since its still there ill have to assume that's not the problem.

i figure, the amp is around 2 years old and still has the original chineese power tubes it came with. so it might be a good time to replace them.
Last edited by moses132049 at Nov 10, 2014,
#11
Quote by moses132049
do you mean spray the contact pins of the pre or power amp tubes?

i replaced my preamp tubes because i heard this crackle, and since its still there ill have to assume that's not the problem.

i figure, the amp is around 2 years old and still has the original chineese power tubes it came with. so it might be a good time to replace them.


I had a similar crackling problem and I pulled and cleaned all the tube sockets this way. It's easy to do em all once you are in there. It solved my issue for about 6 months and then I replaced the stock 5 yr old tubes with new. One of my new JJ pre tubes was a dud and failed shortly after use. I replaced it with an older spare and now all is good in this amp.

Having your tubes tested is the only way to know for sure if they are the problem.
Last edited by Cajundaddy at Nov 10, 2014,