How to repair Orange OR120 100 watt EL34 tube guitar amp famous concert machine 

Nice! Nostalgia is burning. I owned a '75 OR120 back in Sweden. Modded it myself with a master volume and some cap value adjustments. Probably the best sounding amp I ever had. When I moved to the States I had to leave it behind. Still miss that amp.

I had a 1972 OR120..and it was the SWEETEST clean I ever heard. Had to sell it when life got tough...it also needed a lil help (back in 96 when I sold it). Based on my recollection...you made this one sound just like my old 1972. BRAVO!

The best sounding Orange amps are the ones that aren't working. Nobody bought these for their clean sounds, they chose them when Marshalls didn't get dirty enough. I'm old and English. Suffered temporary deafness through many of these back in the day. Enjoyed every minute, strange to say. Plus ça change...

Thanks Terry I have an 80 as well as the 120

Cool wearing the Orange shirt for the video!!

Great fix Terry. You do know you stuff around wiring. Moving and replacing parallel supply wiring under the tubes fix was a good call.

Hi Terry... I don't want to be a meanie pants, but right now at CE Dist, you can get a 100uf can cap @500v. There's a double F&T, and a Double by JJ. I don't know if they'd fit the rings. Also, I cringe a bit seeing radials replacing axials... It's just a style thing, and there's no hate.

Great Job, I liked your sympathetic restoration, particularly the filter cap' replacement. Very interesting about the valve base wiring. I had one of these as a teenager back in the 70's. I worked for weeks in my school vacation to earn the money to buy a brand new OR120. After a while the HT fuse kept blowing. Not having the technical knowledge which I gained later I took the amp back for repair to Orange who did the repair while I waited. I asked what the fault had been and they said that the valve bases were tracking, but I bet the fault was in the wiring to the bases as you explained. This really took me back to my teens! By the way, I used the amp for bass with a JBL 2x15 cabinet. I can confirm that it was very clean and had masses of headroom, I used it for many years, even as a professional musician for a while and it was a great sounding rig.

Love your videos!! You have helped me understand how amps age and when to send in. If you were closer I'd send my amps to you!

Another great job done, love the sound from these amps.

Splendid!!! Awesome information Keep uploading videos..... because we love it......👍🏻👍🏻❤

Wow, they didn't skimp on the transformers

hi guy i really liked replacing the capacitors especially power supply, and installing the new wires is really awesome, your video is awesome thank you very much and see you soon.

Orange meets Fender.... A Forange !! Did you know Orange was originally a make of PC's but when IBM cornered the market, that was over. Great job man, that amp sings.. I have an Orange Tiny Terror 500W Bass ( Hybrid) good stuff for sure.

FWIW both F&T and JJ make can caps that should work with this amp but maybe since they are made in EU they are less easy to find in USA. Also - on the filament wiring, I read that you should wire the same 'phase' (ie wire) to the same heater pin to keep hum down because the pairs of tubes in push-pull are out of phase and so hum gets cancelled out to some degree. Old Orange stuff is ok, I'm less impressed with more recent stuff, I had an AD-5 for a while, Chinese transformers, the OT failed spectacularly and when I asked Orange if I could order a replacement they were very unhelpful, refused to sell parts or give any information, basically trying to force me to send it back to them. Well, given that it was a SE EL84 5w amp, it wasn't exactly hard to source a suitable Hammond OT which ended up sounding better too.

Terry, Why not replace the original filter cap cans with drop in replacements such as JJ or F&Ts. Just seems like less of a hassle and cleaner.

Awesome to watch..... but something I’ll leave to the pros like you.

Great job, that's a sweet sounding amp 👍

Those green filament wires coming from the transformer maybe should have been tightly twisted and shortened like you did with the new green wires. It can make a big difference, I built a high gain amp with ac filaments and virtually no noise thanks to careful layout and wiring job.

Cool. Were you impressed with the circuit Terry? Was it quality? I've never owned or played one.

What a cool old piece! 100W is WAY too loud for my taste, but if you're playing to a stadium, they'd rock the house!

Hey Terry, curious to know the B+ voltage at the output transformer of this amp, I imagine it''s high for 4 x EL34, producing 120W

Fuckin love old Oranges. Great rock n roll and stoner amps

First off, enjoyed the video, as usual. Just curious, since I didn't see it mentioned, but is there any issue with 50 Hz versus 60 Hz line power since this amp originated in London? I'm not assuming there would be any problem if it was either designed for both or this is a US model. I guess I've watched too many Techmoan videos, or remember stereo gear with configuration blocks or switches to select various voltages. Powerline frequency would affect motors and such primarily, if I recall it would only affect output voltage slightly, so minimal impact.

Dual 100uf cap cans are available. A bit hard to find but yeah...

Question - I’d love to add a bright switch to my Orange Brent Hinds Terror but don’t want to brighten both channels, just the lack luster “natural” channel. Thoughts? I thought I’d throw a 220 uf cap in the signal path of that channel but can’t find a schematic. Thanks in advance - cool channel - subbed :)

Terry, those filter caps on the chassis are readily available. Sorry for criticism, but I think the job could have been done with a little more thought. Board caps, good job there.

You could have gotten those can caps. I just did, for a 1978 Hiwatt Custom 50, where the wiring was so beautiful I didn't want to touch it, but I had to! Silver face Fender wiring is a shit show compared to British mil spec. but we are all used to seeing garbage over here so ke sera sera. There is something to be said for neat and clean wiring. You are 10x the tech I will ever be, but look at some pictures of the under side of a 70's Hiwatt if you want to cream your jeans.

Did the owner want to keep the look of the original filter caps? I would have been OK with just changing them directly to the new ones.

I wish I still had mine....Now I want to cry....

Wow man, people here are praising you for a job well done, but those caps are absolutely available and easy to get. Yet you drilled two holes in the chassis of this vintage beauty to cram some others in there instead. Plus, it looks like you didn't twist the filament wires when you moved them. Yikes.

I would like to buy that amp! Would the owner be interested in selling it? Any schematics for that one?

Nice Amp 👌sounds like an old Plexi

Your not going to fix that orange, your going to "peel it"! Ha Ha

I think your friend is pretending to play guitar in order to hang out with you Dr D!

Terry, noticed your can of WD-40. Do you know that they have released: *WD-40* *Contact* *Cleaner* & *WD-40* *Gel* ? They're NO *DeoxIT,* but they now serve a purpose around electronic devices!!

Terry sorted that Orange's electrolytes!

I have a later iteration of this amp. Still from the 70s but with the master volume pot added. It sounds like sludge.

Man that is rad how you did the filter caps.

At least it's an older Orange amp.

Not sure if I'm the only one this happened to, but the video switched to ads in the middle and towards the end. had to wait on the thing to allow me to skip, still forced me to wait 4 seconds (OMG, so much time :-) to finish. I'm one of your Patreon subscribers and if this is something that is going to happen in the future, will have to reconsider that. Sorry to rant, but a big distraction for me. Tom

I can't believe there was not a bit of silastic on that circuit board. They know these amps sit on top of speakers and vibrate for hours. I don't think I will ever buy an Orange amp after seeing this.

How much for a clone of this in a Marshall jcm 800 after market chassis?

Those impedance selectors can lose connection inside

I would have tossed those old filter caps.

Interesting Cap. Repair on side of chassis. Do no harm,as always.