New Poster, New Amp: OTR-120

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deytookerjaabs
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New Poster, New Amp: OTR-120

Post by deytookerjaabs » Sun Jul 22, 2018 9:08 pm

Hey there, just picked this up a couple days back, got to try it out in person and fell in love! Years ago I missed out on a 70's OR-80 Combo at a local shop back in Chicago (now live in Nashville) and since then an Orange has always been on my radar. I figured I'd join up, post some pics, and see if you guys can add any details to the basics. It was sold to me as a '95 OTR-120 made in England by MATAMP and that's about all I know regarding the amp.

Here's the pics:

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I must say, before picking the amp up I was hesitant, I mostly play real clean to a bit of breakup yet every demo online was someone thrashing on some metal. But, after getting acquainted I can say I'd be glad to use the amp in just about any situation, that FAC switch is great to have too! It's got some variations of "British" flavors when you get to twiddling those knobs.

caldurham
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Re: New Poster, New Amp: OTR-120

Post by caldurham » Sun Jul 22, 2018 9:55 pm

congrats on the amp! and welcome!

looks nice! i've only heard a few of them through youtube videos but i thought they sounded really good.

btw i am close to nashville, just a lil past gallatin!

lunchbox
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Re: New Poster, New Amp: OTR-120

Post by lunchbox » Mon Jul 23, 2018 1:08 am

Congrats! Nice amp, and beautiful H-150.

fiveightandten
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Re: New Poster, New Amp: OTR-120

Post by fiveightandten » Mon Jul 23, 2018 1:52 am

Nice amp, congrats! And yes, they do a lot more than heavy metal. The prickly, edge of breakup tones are some of the best, and as you mentioned, the FAC knob gives you a ton of variation there.

That amp appears to be consistent with another OTR we've seen here. It has a 1970's PCB in it, so it's not a Matamp build.

The owner of the other one that looks like this emailed Orange about it. He replied:
"Ok, I got a very helpful reply from Orange. It's not a Matamp build after all - seems like it's a custom amp built by Adrian himself at Denmark Street in 1997-1998 using 70's parts."

See this thread:
viewtopic.php?f=2&t=50506

Your amp has the same PCB, and a lot of the same types of caps, which, I might add, were not used in the Matamp built OTRs.
Image
'71 GRO100 || '96 OR-80 || AD30 || '64 AC-50 || AC-30TBX || Hiwatt DR504 || HI-TONE HT30
LP Standard || LP Studio || LP Custom Lite || Ric 620 || Ric 360 || MIA Tele || SG 61 RI

Les Paul Lover
Duke of Orange
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Re: New Poster, New Amp: OTR-120

Post by Les Paul Lover » Mon Jul 23, 2018 6:07 am

Congrats - again!!! As said on the tdpri forum, I would love to try one of those one day.

Thanks for the pic of the PCB. The design of the circuit looks so simple...... pretty surprising really.
Ant

Orange Gear: RV50 MKI, R30, AD15, PPC212
And.... Genz Benz Black Pearl 30
Past Orange: AD30TC Combo, TT, AD5


Guitars: Gibson Les Paul Standard Faded, Vigier Expert Retro 54, Gibson SG 70s Tribute, Aria Pro II RS X80, G&L ASAT Special Tribute

deytookerjaabs
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Re: New Poster, New Amp: OTR-120

Post by deytookerjaabs » Mon Jul 23, 2018 1:59 pm

caldurham wrote:
Sun Jul 22, 2018 9:55 pm
congrats on the amp! and welcome!

looks nice! i've only heard a few of them through youtube videos but i thought they sounded really good.

btw i am close to nashville, just a lil past gallatin!
Nice! I'm on the west side of town, I think they call it "Sylvan Park."

deytookerjaabs
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Re: New Poster, New Amp: OTR-120

Post by deytookerjaabs » Mon Jul 23, 2018 2:09 pm

fiveightandten wrote:
Mon Jul 23, 2018 1:52 am
Nice amp, congrats! And yes, they do a lot more than heavy metal. The prickly, edge of breakup tones are some of the best, and as you mentioned, the FAC knob gives you a ton of variation there.

That amp appears to be consistent with another OTR we've seen here. It has a 1970's PCB in it, so it's not a Matamp build.

The owner of the other one that looks like this emailed Orange about it. He replied:
"Ok, I got a very helpful reply from Orange. It's not a Matamp build after all - seems like it's a custom amp built by Adrian himself at Denmark Street in 1997-1998 using 70's parts."

See this thread:
viewtopic.php?f=2&t=50506

Your amp has the same PCB, and a lot of the same types of caps, which, I might add, were not used in the Matamp built OTRs.

Thanks for the info! Yeah, I read somewhere that the 90's stuff was MATAMP but I stand corrected. That's why I signed up here, no much info out there on the regular forums. The 70's parts thing is interesting, I'm assuming the transformers are from the 90's though? I'll say they've got a good bit of patina/rust even when compared to my vintage amps, but the rest of the amps is pretty darn clean except for the dingus who practically stripped all the chassis mount screw heads!
Last edited by deytookerjaabs on Mon Jul 23, 2018 2:12 pm, edited 1 time in total.

deytookerjaabs
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Re: New Poster, New Amp: OTR-120

Post by deytookerjaabs » Mon Jul 23, 2018 2:10 pm

Les Paul Lover wrote:
Mon Jul 23, 2018 6:07 am
Congrats - again!!! As said on the tdpri forum, I would love to try one of those one day.

Thanks for the pic of the PCB. The design of the circuit looks so simple...... pretty surprising really.

I've got this theory...less knobs, less parts, bunch of tubes, and giant iron = cool :lol:

satchmodog
Tiny Terror
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Re: New Poster, New Amp: OTR-120

Post by satchmodog » Mon Jul 23, 2018 5:00 pm

Congrats, awesome amp. Yeah, people love the Orange crunch tones because they're so solid and so distinctive. A lot of people also dismiss the cleans because they're darker and you don't get to do the EQ thing on so many amps. But, I go with orange for those very reasons

fiveightandten
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Re: New Poster, New Amp: OTR-120

Post by fiveightandten » Mon Jul 23, 2018 8:22 pm

deytookerjaabs wrote:
Mon Jul 23, 2018 2:09 pm
Thanks for the info! Yeah, I read somewhere that the 90's stuff was MATAMP but I stand corrected. That's why I signed up here, no much info out there on the regular forums. The 70's parts thing is interesting, I'm assuming the transformers are from the 90's though? I'll say they've got a good bit of patina/rust even when compared to my vintage amps, but the rest of the amps is pretty darn clean except for the dingus who practically stripped all the chassis mount screw heads!
I've heard amps of that era were Matamp builds, I've heard Trace Elliott, and I've heard both. I'd say your amp is neither, and was likely one of a short run that were built by Ade Emsley. It looks just like the one that Orange confirmed in the thread I linked.

It's tough to tell in the photo, but it looks like there may be a signature on the PCB next to the rectifier diodes. Maybe it's legible in person.

The transformers do look to have some oxidation, but then again so do the roll bars (tighten those up, BTW). It's likely that the amp spent some time in a humid basement or similar setting. I wouldn't worry about it. You can use some chrome polish to clean up the roll bars a bit. The bell covers on the transformers can always be replaced, easily. I'd just clean them up a bit if it bothers you. They say that oxidation on the laminations is part of the sound of older transformers.

The PCB is definitely 70's, though the OTR has a number of deviations from the OR-80/120 circuit. It's mostly component values, some unique to the OTR, but the phase inverter was wired a little different as well (unique to the OTR, lower value plate and cathode resistors). So he used the 70's PCB, and "modded" the amp to OTR specs from there.

I wonder what the red dots are all about. That's curious.

It's unfortunate about the chassis bolts. I see someone broke the welds on the threaded bung on one corner. You can find a skirted nut that is the same thread size/pitch, and JB Weld it in there. Let it cure, and put a little orange touch up paint over it for good measure. It'll look mostly good as new.

-Nick
Image
'71 GRO100 || '96 OR-80 || AD30 || '64 AC-50 || AC-30TBX || Hiwatt DR504 || HI-TONE HT30
LP Standard || LP Studio || LP Custom Lite || Ric 620 || Ric 360 || MIA Tele || SG 61 RI

deytookerjaabs
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Re: New Poster, New Amp: OTR-120

Post by deytookerjaabs » Tue Jul 24, 2018 1:08 am

Yeah, I was going to run to the hardware store to get an extra bolt as I noticed one was missing...then I saw the insert thread was gone too. Uhg, 3/4 ain't bad I suppose :lol:

There's definitely a signature there, next time I dive in I'll check it out.


Bad news, double bad news though. It started to make some slight whooshing (note with nothing plugged in) with the gain anywhere below max yesterday. Swapped preamp tubes, no luck, tapping on the JJ KT77's had no effect and they look brand new (tube depot stickers still white/shiny). Then, I'm rotating the knobs and something even worse happens...really bad self oscillation loud square wave type noise if both the presence and treble are dimed at the same time, even with the gain at zero. Take either knob back a hair and it goes away but I'm pretty sure it's not supposed to be like that. :roll:


Plus, after the splurge, I'll have to wait a bit to bring it to my local amp doctor as he's also going to need to work on my super reverb, argh. Good times, glad I have a number of amps.

fiveightandten
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Re: New Poster, New Amp: OTR-120

Post by fiveightandten » Tue Jul 24, 2018 3:16 am

deytookerjaabs wrote:
Tue Jul 24, 2018 1:08 am
Yeah, I was going to run to the hardware store to get an extra bolt as I noticed one was missing...then I saw the insert thread was gone too. Uhg, 3/4 ain't bad I suppose :lol:

There's definitely a signature there, next time I dive in I'll check it out.


Bad news, double bad news though. It started to make some slight whooshing (note with nothing plugged in) with the gain anywhere below max yesterday. Swapped preamp tubes, no luck, tapping on the JJ KT77's had no effect and they look brand new (tube depot stickers still white/shiny). Then, I'm rotating the knobs and something even worse happens...really bad self oscillation loud square wave type noise if both the presence and treble are dimed at the same time, even with the gain at zero. Take either knob back a hair and it goes away but I'm pretty sure it's not supposed to be like that. :roll:


Plus, after the splurge, I'll have to wait a bit to bring it to my local amp doctor as he's also going to need to work on my super reverb, argh. Good times, glad I have a number of amps.
He'll probably have to clean up the OT primary wiring. I'd bet that's the source of your oscillation. I'd get the leads out from under the PCB as much as possible. They should come through the chassis and make a direct turn towards the back end of the chassis near the tube sockets, instead of going under the PCB like they are. They're too close to the negative feedback loop components, PI circuit, and maybe even the tone stack.

A good tech should be able to track it down. But he's likely going to have to clean up that wiring a bit. The PT wiring isn't the neatest either. If it were me, I'd clean that up, clean up the wiring around the can caps, get that standby switch wiring neatened up, and most important of all, get the OT primary leads out from under the PCB. But the last one may be all you need to get the amp stable. If they're not long enough, at least get them so they're near the top of the board when they make a turn towards the sockets.

As for the whooshing sound, that's a tough one. It could be related to the oscillation and lead dress. I'd clean up the wiring and see what happens from there. If it's unrelated, you'll have to just track it down.

-Nick
Image
'71 GRO100 || '96 OR-80 || AD30 || '64 AC-50 || AC-30TBX || Hiwatt DR504 || HI-TONE HT30
LP Standard || LP Studio || LP Custom Lite || Ric 620 || Ric 360 || MIA Tele || SG 61 RI

Les Paul Lover
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Re: New Poster, New Amp: OTR-120

Post by Les Paul Lover » Tue Jul 24, 2018 6:15 am

It's worth keeping in mind that at 21yo, if made in 97, those capacitors have pretty much reached the end of their useful life.

If you do bring it to a tech, you might want to factor in full electrolytics replacement, even if they don't cause the noises, as preventative maintenance.
Ant

Orange Gear: RV50 MKI, R30, AD15, PPC212
And.... Genz Benz Black Pearl 30
Past Orange: AD30TC Combo, TT, AD5


Guitars: Gibson Les Paul Standard Faded, Vigier Expert Retro 54, Gibson SG 70s Tribute, Aria Pro II RS X80, G&L ASAT Special Tribute

fiveightandten
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Re: New Poster, New Amp: OTR-120

Post by fiveightandten » Tue Jul 24, 2018 5:02 pm

Les Paul Lover wrote:
Tue Jul 24, 2018 6:15 am
It's worth keeping in mind that at 21yo, if made in 97, those capacitors have pretty much reached the end of their useful life.

If you do bring it to a tech, you might want to factor in full electrolytics replacement, even if they don't cause the noises, as preventative maintenance.
This is a thought. Though, they last surprisingly long in these amps. I still have all the original caps in my 90's OR-80 (1995 build), and it sounds/functions great. I have the original 100 mfd cans in my 1971 head as well.

I have a bunch of Sprague atoms sitting in a box somewhere, but I haven't found a need to install them yet! That could potentially be the source of his whooshing noise tough.

-Nick
Image
'71 GRO100 || '96 OR-80 || AD30 || '64 AC-50 || AC-30TBX || Hiwatt DR504 || HI-TONE HT30
LP Standard || LP Studio || LP Custom Lite || Ric 620 || Ric 360 || MIA Tele || SG 61 RI

deytookerjaabs
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Re: New Poster, New Amp: OTR-120

Post by deytookerjaabs » Tue Jul 24, 2018 6:33 pm

Well, woke up this monin' and did the po' boy mess around as a last resort type stuff. De-Oxit all sorts of contacts, re-swapped preamp tubes, tighten a couple things then turned it on and after a few hours still no "whoosh." In fact, running pretty quiet, almost creeping me out. Dimed the treble/presence too, no oscillation, wierd. Keeping my fingers crossed.

Also got to the hardware store for m5/6 screws. No square nut to faux weld in though, guess I'll have to order that online or try another hardware spot. Thanks for all the assistance!


I can say after a few more hours of playing I think I'll eventually order a pair of G12-65's and ditch the vintage 30's. It already sounds good, they're solid and loud speakers, but they keep it so I won't go past "5" on the treble knob, the less efficient darker speakers change the feel a bit, allow wider knob twiddlin', and are my thing for these kind of big iron amps.


Oh, the writing on the PCB seemed to say "NLOL DRIVE"...no idea, not a signature though. And, to me, compared to every other part of the amp the transformers still look like they themselves sat in a moldy basement before being put on the amp. Even the wire on them has that olive dark tint to all the colors which I don't recall seeing on my other 90's era amps. Seems a bit fishy, like they were used/scrap, lol. But, I guess maybe that's how they looked.

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