Hartke A70 Cracking

[dov]

Hi folks,

 

Has anyone encountered this issue before? Amp clicks with nothing plugged into it. Tested with headphones too and the clicking persists through the headphones. 

 

It's a Hartke A70 if that helps?

 

I'm none the wiser as to what could be causing it, so if anyone could help shed some light that'd be great!

 

Cheers.

[Mottlefeeder]

Often a crackle can be traced to something as simple as dirty contacts on a socket, to my first action would be a plug into each signal socket in turn and see if the noise persists or disappears. For the effects loop, take a guitar lead and link the Fx send to the Fx return.

Next, you could try splitting the circuit into blocks and checking each block. Try feeding the signal from the Fx send to a mixer or another amplifier and see if that crackles. Next, take a signal from another source into the Fx return, and see if that crackles.

That's probably as far as I would advise you to go unless you are knowledgeable enough to take the amp out of the combo and work on it without electrocuting yourself.

David

[Bigguy2017]

That's what's called 'motorboating'...  something has gone into oscillation.

 

Many possible causes - bad connections, dry joint, bad cap, bad component among them.

[paul_5]

As above. I’d start with the checking and possibly replacing the electrolytic caps, they have a short shelf life (about a decade!) compared to most other components .