Cool. Sound-wise as well as circuit-wise? Do you have a preference for one or the other for any reason?

I think I might have read something about which circuit revision / original OR year they were based on before, but I'm not recalling where at the moment. Does anyone remember?

I've found that if I lower my guitar's pickups and stay off of the bridge pickup, I can get very clean sound from the amp with the settings at about what they're shown in this video: https://youtu.be/Ct0_6t8mYzM So, the guitar pickups and setup are playing a big role here. What do people think of th...

Here are some pictures the person who owned it before me took:

I might open it up to take additional photos, but for now here are a couple of internal photos I took a while ago. No work has been done on the amp since I got it over 2 years ago.

Thanks for the insightful information, everybody. I spotted this video of another OR-80 OD, in which it sounds like it's pretty darn clean with the gain knob at 50% - which is quite different than what I get from my OR-80 OD: https://youtu.be/Ct0_6t8mYzM I use Lace Sensors which are higher gain, tho...

My friend's OR120 was rebiased recently after he had 2 of its tubes pulled to bring the wattage and volume down a bit. My OR80 OD was reportedly serviced shortly before I bought it, with new tubes installed. I suspect it's biased properly because the sound is pretty good and clear, while still withi...

Hi bclaire, thanks for the reply. As shown in the photo of my amp settings I posted, my master volume is all the way up. I have JJ EL34 and Beijing Shuguang 12ax7 tubes in the amp right now. I did a storm of reading about differences between the 70's Orange amps yesterday and I currently have the im...

I have an OR-80 Overdrive with the master volume, and a friend has an OR-120 without a master volume. My friend says he needs to have the gain turned around 3/4 of the way up before he starts getting breakup from the amp. But on my OR-80 OD I get breakup almost as soon as the gain is turned up, and ...

Thanks for the suggestions. Basically you just need to find out what diameter and thread pitch they have. If some are stripped, I’d expect the nut they screw into is stripped as well. May be repairable with a tap if so. But as mentioned a good hardware store should get you sorted. Bring the screw wi...

The 47n are phase inverter coupling caps, and not electrolytics in the B+ rail. They look to have been replaced, and were likely 68n (.068 mfd) WIMA caps from the factory. The 47n value shaves a little low end off in comparison. Some of the tone stack caps look to have been replaced as well, but I ...

All 4 screws for my 1978 OR-80 head have some rust on them, and two of them have become stripped. Is there a place that sells replacement screws?

I opened up my 1978 OR-80 OD and made a list of the capacitors. Outside of the chassis: 2x 100 uf 450 VDC Inside of the chassis 2x 32uf 450 VDC 2x 10uf 160v 2x 47N 1KV 2x 47uf 25 WVDC 2x 15uf 450V Here are pics: https://i.imgur.com/ZieXMEX.jpg https://i.imgur.com/5LzTe6f.jpg The layout and number of...

I want to bring my my 1978 OR-80 to a tech for a recap, but I want to first order the caps myself to make sure they're the right values and a good brand (probably F&T). I'm not sure what values of caps I should be ordering for it, though. Is there a list of all the caps that I should be replacing? H...