Crackling...

[Carolyi]

Lately I’ve been experiencing crackling noises after playing my amp for about 20 minutes. My current setup is as follows:

Guitar -> Rack pre-amp unit -> effects unit -> rack power amp -> cabinet

The pre amp is tube, so I tried replacing the tubes, no dice
Power amp is solid state, so no tubes to look at there
Cords are only a couple months old

The crackling doesn’t start immediately it takes a little, but once it starts it quickly gets progressively louder until I turn the amp off, any idea what’s the cause?

P.S. Preamp from the 80’s, Lee Jackson perfect connection

 

[311splawndude]

Tell us more about 'replacing the tubes' because that is my #1 guess.

I don't know what your effects unit is but I def can get crackling with bad connections to pedals and/or my NS2.

Possible grounding issue?

Solder joint going bad/getting worse?

 

[griff10672]

my vote will be for the electrolytics .....In my experience with a few Mesa's ..... if it wasn't a simple microphonic tube ...... it was the caps ..... especially if it starts a little after the amp is turned on ......

 

[Dave M]

Start a process of elimination first.

Remove the fx processor from the chain. Does that change anything?

Next, remove the preamp so on the poweramp is on. Does that change anything?
If no, then it's eithe th poweramp or interconnections.
If yes, try something else to replace the Lee Jackson (e.g., different preamp, signal generator, etc.). Does that change anything?