Is the biamp switch in the pre-amp stage?

[cnjvh]

I've got a bad biamp/full range switch in my Hartke head. Sometimes the sound in the cabinets will begin to crackle and cut out. If I hit the biamp switch a bunch it clears up and will be fine for a few weeks.

Now up until today I believed it was only affecting the sound from the cabinets (the amps power stage). However, today when playing I noticed the same issue happening on the effects return.

How is this kind of switch generally wired? Can a bad biamp switch affect the sound in the effects loop? Or is this switch usually "downstream" in power and stage?

Thanks : )

 

[BassmanPaul]

Corrosion on the contacts of the switches on the effects loop jacks cause a plethora of problems. These can be minimised by linking the send and return with a short signal cable. Try this tip and see if it helps.

 

[BadExample]

How is this kind of switch generally wired? Can a bad biamp switch affect the sound in the effects loop? Or is this switch usually "downstream" in power and stage?

Almost certainly the biamp circuits are after the effects loop. Otherwise, the loop would only work for either the Hi channel or the Lo channel. Mine is certainly after the loop, but not a Hartke.

 

[cnjvh]

Thanks much for the help, going to start going through it tomorrow. Appreciate the suggestions and information.