orange overdrive or-120m

domi-bot · Post by **domi-bot** » Tue May 15, 2007 6:17 pm

hello there!

i recently bought a used orange head, and i thought maybe this here forum could help me date it.

on the back it says:

MODEL No OR 120 M
Serial No 016371

then there's a little metal plate with a warning about high voltage and so on and another number that reads: 64428.

here's a few pictures:

thanks in advance!

Post by **bclaire** » Tue May 15, 2007 8:27 pm

Looks like a late 70's- probably 77 or 78 since they stopped making them the first time around in 1978.

Check out www.orangefg.com for more info as well.

Andy H. · Post by **Andy H.** » Tue May 15, 2007 9:05 pm

Hi domi-bot. Welcome!

Very late '70s model I'd say. Serial numbers aren't a dead cert but Orange amp timeline guidelines suggests '79:
http://www.geocities.com/diytech_ct//timeline.html

Only way to tell for sure is if there is a date tag inside. However that means exposing the high voltage innards and you can't go touching anything in there!!! Not even if the amp has been unplugged for several days as there may well still be lethal charges stored in the big capacitors in there. However as a lot of the later '70s ones did have a dated completion tag you may be lucky. Here's my OR120M:

Chassis no: 015637
Backplate no: 63896
Date on tag; 10th Aug '78

What I'd actually suggest is getting a good amp tech to check the amp over. A few parts (like those capacitors) if original would be needing replaced for safety anyway. Get the tech to check for a date while he's in there.

Andy.

domi-bot · Post by **domi-bot** » Tue May 15, 2007 9:56 pm

thanks a lot!

i'm not going to open it, i don't know anything about stuff like that. about the replacing of capacitors: i don't know if they're original parts. the guy i bought it from said he used it for 15 years, so i guess they work fine,... but i'll ask him about that to be sure.

another question: the amp doesn't have a standby-switch. i read somewhere else that it is possible to build one in it. the question is: is that neccessary/would you suggest doing so?

Andy H. · Post by **Andy H.** » Wed May 16, 2007 3:23 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by domi-bot
 thanks a lot!

i'm not going to open it, i don't know anything about stuff like that. about the replacing of capacitors: i don't know if they're original parts. the guy i bought it from said he used it for 15 years, so i guess they work fine,... but i'll ask him about that to be sure.

another question: the amp doesn't have a standby-switch. i read somewhere else that it is possible to build one in it. the question is: is that neccessary/would you suggest doing so?
<hr height="1" noshade id="quote"></blockquote id="quote">About caps. Best advice is that if the big filter caps haven't been replaced in 15 years or so, the time is ripe. As I say they don't last forever and I have had an oldie explode in one of my amps once - very nasty and messy as they are full of corrosive goo. It is a pretty standard job for an amp tech and the parts are cheap so for reliability and performance I'd strongly advise doing it.

Standby: Personally I don't worry about not having it at all. I tend to power up the amp for the duration and switch it off when I'm done. Others do fit a standby.

LOOK HERE!

Main thing with these amps is to make sure you are using very good quality power valves. OR series amps run them at higher than usual voltages and cheap modern valves will just die very quickly. Good ones will last well though and are a real must with these amps!

Andy.

domi-bot · Post by **domi-bot** » Sat May 19, 2007 1:34 pm

thanks!

i've got another question, i know it's probably not the right section of the forum, but since this thread is here...

can anyone recommend a cheap (less than 300 euros/$420 US) 4x12 cabinet to use with this amp? i currently can't afford buying an orange cabinet or anything similar, so i'm looking for a cheap but good (temporary) solution.

Andy H. · Post by **Andy H.** » Sat May 19, 2007 3:15 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by domi-bot
 thanks!

i've got another question, i know it's probably not the right section of the forum, but since this thread is here...

can anyone recommend a cheap (less than 300 euros/$420 US) 4x12 cabinet to use with this amp? i currently can't afford buying an orange cabinet or anything similar, so i'm looking for a cheap but good (temporary) solution.
<hr height="1" noshade id="quote"></blockquote id="quote">I'd honestly suggest going second hand. But if going for the cheap temporary option check out Musichaus Thomann for mail order. They have pretty well all price ranges covered. Can't speak for the quality or sound (I wouldn't expect either to be too good!) but you can pick up a 4x12 for about Ã¢â€šÂ¬170 up from them. I've dealt with them and they seemed very helpful and sound.

http://www.thomann.de/de/index.html
http://www.thomann.de/de/4x12_gitarren_boxen.html

Andy.

domi-bot · Post by **domi-bot** » Sun May 20, 2007 1:42 pm

hehe yeah, i buy most of my stuff there, they are pretty good. they have quite a lot of cabinets, i think i'm going to sttle for a really cheap 2x12, actually. i don't think i can afford more at this moment.

the tubes have been exchanged about 5 years ago and not seen much use since then. i guess i don't need to replace them?

Andy H. · Post by **Andy H.** » Mon May 21, 2007 10:23 am

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by domi-bot
 ...i think i'm going to sttle for a really cheap 2x12, actually. i don't think i can afford more at this moment.

the tubes have been exchanged about 5 years ago and not seen much use since then. i guess i don't need to replace them?
<hr height="1" noshade id="quote"></blockquote id="quote">Just make sure the speakers in the cab have plenty of power handling. If Celestions than 120w rating will cover it. Anything else I'd look for more. (These amps, like most all valve amps, will probably put out more than their clean rating when fully driven. Celestions are usually conservatively rated and will actually take that, but others rated for 120w might not so make sure there is plenty power handling to spare.

Without use valves don't really age unless bashed about so probaably no problem. If they sound fine they probably are. But remember what I said about the need for strong power valves with these amps. What sort are in there, do you know? At any rate get a tech to check the amp is properly biased for them so they aren't run too hot or cold, and to check out the filter caps too at the same time.

Andy.

Simon Wicks · Post by **Simon Wicks** » Mon May 21, 2007 12:15 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Andy H.
 Hi domi-bot. Welcome!

Very late '70s model I'd say. Serial numbers aren't a dead cert but Orange amp timeline guidelines suggests '79:
http://www.geocities.com/diytech_ct//timeline.html

Only way to tell for sure is if there is a date tag inside. However that means exposing the high voltage innards and you can't go touching anything in there!!! Not even if the amp has been unplugged for several days as there may well still be lethal charges stored in the big capacitors in there. However as a lot of the later '70s ones did have a dated completion tag you may be lucky. Here's my OR120M:

Chassis no: 015637
Backplate no: 63896
Date on tag; 10th Aug '78

What I'd actually suggest is getting a good amp tech to check the amp over. A few parts (like those capacitors) if original would be needing replaced for safety anyway. Get the tech to check for a date while he's in there.

Andy.

<hr height="1" noshade id="quote"></blockquote id="quote">
Damn Andy, whats going on with those filter caps? It looks as if you have several stacked together in parallel. Are they hot glued to the PCB? I'd be a little worried if they arent. The old Orange/Matamps are famous for loosing their caps due to rattles.

Andy H. · Post by **Andy H.** » Mon May 21, 2007 2:07 pm

Yeah they are different value caps paralleled to give the correct total values Simon. They are also quite securely attached thanks!

I suspect that work wasn't a JP job but by another tech friend of mine. Not so pretty perhaps but fully functional. (Mr Phillips himself does spectacularly neat work as a rule!) He has been in there himself but found nothing at all to worry about. I'll probably try harder for the right value caps next time though, a few years further down the line, but that was a perfectly acceptable job IMO.

Other non original parts are the mains switch and fuse holders, a few smaller caps, and the choke. It is a working amp of course so not in museum piece original condition...

Andy.

Simon Wicks · Post by **Simon Wicks** » Mon May 21, 2007 3:11 pm

Yeah, my orange seems to have a non-original switch too. Maybe they were crap back in the day? My matamp had an old black bat switch. I sold it to a Marshall enthusiast to pay for more bits for my restoration project.

BTW, do i spot a radial V1 cathode bypass cap on the end of that board? Heresy sir!

Andy H. · Post by **Andy H.** » Tue May 22, 2007 4:26 pm

Thanks for your continuing concern there Simon!

Dunno. Without digging it out of the loft and opening it up I can only see what you can right now. Wasn't planning on that. Precisely which of the pretty coloured lumps were you casting aspersions on, and what were your thoughts?

:?::?:

Andy.

Orphin · Post by **Orphin** » Tue May 22, 2007 4:34 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Orange/Matamps are famous for loosing their caps due to rattles.<hr height="1" noshade id="quote"></blockquote id="quote">
 
They are?
Mine looks fine after 37 years. I hope I never get those problems..

Simon Wicks · Post by **Simon Wicks** » Tue May 22, 2007 6:21 pm

The glue tends to go bad after a while and they loosen up. I've seen several OR120 and GT-120s with that problem. Mine was fine though, i had a hell of a time getting the old caps off while recapping it!

orange overdrive or-120m

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