Orange OR 80 Restoration

Posted by on September 1, 2014 in Amp Repair, Electronics Repair, General, Unused | 0 comments

A 1972 Orange OR 80 amp that had been beaten hard came to me recently for a full restoration. I wish I had the “before” photos, but I was camera-less at the time. It sounded really bad and looked even worse. It was covered in grime to the point that the torn and tattered orange tolex was nearly black in places. The power switch was snapped off in the on position, and the AC cord was frayed. The controls were all scratchy. It was rough.

Gut Shot of restored Orange OR80.

Gut Shot of restored Orange OR80.

I replaced the 40+ year old electrolytic capacitors, power switch, AC cord, HF Drive pot, screen grid resistors (one was open), and EL34 power tubes as well as 12AX7 pre-amp tubes. I replaced the fuses with the correct values (I’m always surprised how many amps I see with wrong value fuses in them). Then I adjusted the bias on the EL34 tubes to within safe operating range.

Topside of the freshly restored and cleaned OR80 chassis.

Topside of the freshly restored and cleaned OR80 chassis.

While I had the tubes out I gave the chassis a thorough cleaning and vacuuming. It was very dirty to say the least! Notice the two empty holes in the chassis. This was to facilitate adding another pair of EL34 tubes to make this an OR 120 with twice the power. I can’t even imagine!

Backside of '72 OR 80 with missing power selector plug.

Backside of ’72 OR 80 with missing power selector plug.

Somewhere along it’s path this amp lost it’s power selector plug. Fortunately, it works as is. The transformers on this amp are serious business, and it’s heavy. Very well made.

Restored OR 80 amp in cleaned cabinet.

Restored OR 80 amp in cleaned cabinet.

Here is the almost finished restoration, with a few places left to glue down the tolex. This was as clean as I could get the tolex with Simple Green and a stiff brush. It is stained somewhat, but MUCH better looking than when it came in. And, it sounds fabulous!

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