foarob1

replaced power tubes not preamp , sorry

Hi I have a spider valve mki that i have had for about 2 years that i havent had any issues with until recently. When it is turned on it works fine for a few minutes then starts to make a terrible squeeling/ feedback kind of noise. It is louder than than the guitar and will do it at all volume levels. It will still do it even if you unplug the guitar from the amp. I have replaced the preamp tubes with a set I had laying around and no change. any insight would be great , Rob