I found a Sound Master PA by Barnum head at a thrift store today, $10. Has anyone heard of this company? I can't seem to find any information about the company. The PA doesn't have an model number anywhere visible (I haven't taken it apart, yet.) It had a plaque that said it was custom made for Powell Junior High in Mesa, AZ. I was astonished to find out it actually worked when I got home, it's pretty beat up and I can hear some things rattling on the inside. I plugged my bass into it and plugged the head into my 115BX and it started feeding back horribly. I turned all of the knobs to 0 and started adjusting from there. When I turn the midrange or bass up is when it starts to feedback, treble just induces hiss and noise. The sound is pretty distorted and it drops in volume sometimes. Most of the knobs can use a bit of cleaning or replacing. How would I start fixing this up to make it actually usable? Outside of all of these negatives, it does sound pretty good. It's fairly loud, too. Enough words, onto pictures. Oh and ignore the room, it's in the middle of being redone.