Hey Orange Hero, Thanks for the schematic. I'm sure that the output problem is originating from the negative feedback loop circuit. The presence control does not function and the volume of the amplifier does not change when I disconnect the negative feedback wire from the speaker selector switch's "...

This is a pics and text model, but the schematic you just linked me to is closer to what I'm seeing on this circuit board. Look at the inside of this amp. Does it look like it was rewired by someone else? <img> <img> Like I mentioned earlier, when I disconnected the negative feedback wire from the "...

Also, the schematic you sent me does not match up with what's on this circuit board. So far, there are about 18 (!) resistors that DO NOT match this schematic. I am putting in another call to Orange to see if any of their amp gurus know anything about this.
I'll try and keep you posted.

Thanks for the reply, and in answer to your questions, yes, yes, and yes. I've noticed that there are 5 test points on the circuit board labeled TP1 through TP5. It would be nice if anyone knew what the voltages should read. The readings I get are; TP1 507 vdc TP2 399.8 vdc TP3 348 vdc TP4 .001 vdc ...

Hello Peoples Of Orange, This is my first post, and I'm honored to be here. I've never worked on an Orange amp. I have a used OR80 head that exhibits lower volume output that I would expect. When it was first brought in, the amplifier had an over-twisted gain pot and the customer suspected that as t...

Name- RC
Location:Villa Park, IL.
Amp Model:OR80
Serial Number:575
Date finished (if known**): (0095 written in marker inside chassis)