Amp Crackle from cabinet vibration.

[jkey04]

The rocket that i built almost a year ago now has started to crackle when i play a low note through it, but only when it is sitting on the speaker cabinet. It does it with all my guitars and with/without pedals in the chain. I recently installed tube retainers on all the tubes, and this helped some but not completely.

Is there anything you guys recommend to resolve this problem? Could there be a bad solder joint somewhere that fails with excessive vibration? I guess it could possibly be a bad tube? I haven't changed them to test that theory yet.

[redshark]

That is a bad joint. This is what I do:

With a rubber mallet hit the edges of the chassis(gently) with the amp on, unplugged, of course connected to a speaker cab and not screwed to the wood cabinet. You will hear the crackling noise when hitting the chassis. That will mean is a bad joint. Then with a chopstick tap lightly every connection, turret, sockets, pots and all joints until you find the connection(s). Retouch those joints and repeat until you have no crackling noise. Although it sounds unorthodox it works!!

[M Fowler]

with a chopstick tap lightly every connection, turret, sockets, pots and all joints until you find the connection(s). Retouch those joints and repeat until you have no crackling noise.

Exactly what I do as well.

Mark

[xtian]

An alternative method is to pump a sine wave into the input, at a frequency and volume that makes the crackle happen continually. Then you can use your chopstick to try to quiet the crackle.

[JazzGuitarGimp]

An alternative method is to pump a sine wave into the input, at a frequency and volume that makes the crackle happen continually. Then you can use your chopstick to try to quiet the crackle.

Or an oscilloscope to track it down...

[VacuumVoodoo]

Could also be shaky screen grids in power tube(s). Certain new production tubes are notoriously doing this after only a few hours use in a combo.

[jkey04]

Thanks!

I think thats got it. I went in and touched up a few solder joints, and now it seems to be crackle-free. Hopefully it stays that way because the amp sounds incredible. It has been my #1 above my Maz18 and Ghia since the time I completed it last summer. Cannot beat the touch sensitivity, especially with a tele!

[redshark]

Thanks!

I think thats got it. I went in and touched up a few solder joints, and now it seems to be crackle-free. Hopefully it stays that way because the amp sounds incredible. It has been my #1 above my Maz18 and Ghia since the time I completed it last summer. Cannot beat the touch sensitivity, especially with a tele!

A tele with good pickups is amazing with the rocket!!