Ashdown ABM 300 Volume Problem

[omox]

I just recently bought an Ashdown ABM 300 (Original UK Built model) and I've noticed some sort of volume cut. I've noticed it for awhile, but today kind of confirmed it. In rehearsal I plugged it in after not using it for a couple days and it sounded perfect, then mid set it all of a sudden cut the volume, like it was running half power or something. If I turned it up it still wouldn't be very loud, not half as loud as it was. Seems like it was running half power or something like that... Does anyone know what this could be?

 

[Seejay]

It could be the tube in the pre-amp on it's way out, does the problem go away when you have the valve drive knob turned all the way to clean?

 

[RickenBoogie]

This is a combo amp? What spkrs? Also, try patching a short cord in the fx loop send and return jacks. Sometimes dirty contacts can cause this.

 

[omox]

Sweet. I will try that. Yeah, I even if I turn the valve drive all the way down, and off it still does it. That was my first guess too.. I'm using this through my 4x10 Ampeg Heritage Cab. You think it could be a problem with the cab?

 

[RickenBoogie]

No, I still suspect the effects loop. They get dirty, and cut your signal.