Ampeg PF800 gain knob/peak/static

[henryjurstin13]

Been using this PF800 just fine for years. Never gigged, just at home & not pushed hard for hours…. I’ve sifted through the threads about the issues, but I didn’t come across this one. Maybe someone has experience/insight.

Gain knob seems to do nothing, until max. Then, peak light ON, and what would be gain sounds like static spikes. This happens through headphones, 1/4 Jack, speakon Jack, and different cabs (8 & 4 ohm options). Passive bass, with pedalboard, and plugging straight into amp.

 

[agedhorse]

This is a symptom of a broken gain control allowing the gain stage to go open loop.

a QUALIFIED service tech should be able to fully diagnose and repair this without difficulty or unreasonable expense.

 

[henryjurstin13]

This is a symptom of a broken gain control allowing the gain stage to go open loop.

a QUALIFIED service tech should be able to fully diagnose and repair this without difficulty or unreasonable expense.

Well, that definitely sounds better than I expected…. I was ready to commit to the Tone Hammer, as I expected this repair would exceed the value of the amp!

 

[agedhorse]

Well, that definitely sounds better than I expected…. I was ready to commit to the Tone Hammer, as I expected this repair would exceed the value of the amp!

Unless I am missing something, it shouldn’t be very costly.

 

[beans-on-toast]

If the nut that attaches the pot to the panel is loose, stress can be put on the pot's solder joints. You may have a bad pot as was suggestesd. It could also require resoldering and tightening. Try wiggling the gain potto see if it's loose and if the static gets worse when you do so. Either way, a tech will sort it.