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Orange OR80 OPTX replaced with


Senior Member
Just purchased an OR80 reissue and found it had a output tranny replaced with a #013897 which I see meets many different applications from mesa to fender bassman.

Any thought about this and what it has done to this Orange amp?

It seems to have a wonderful tone and plenty of headroom.


That OT is the stock OT in the Fender Bassman 70--- The Bassman 70 is an Ultralinear design, so the OT should have screen grid taps on the OT primary.
It sounds like someone took the quick and easy route when sourcing a replacement OT for your Orange amp.

Bassman 70 schematic: http://www.webphix.com/schematic heaven/www.schematicheaven.com/fenderamps/fender_bassman70.pdf

My OR80 came to me with the orig OT missing and replaced by a Super Reverb 2 ohm OT, power cable cut off, other problems, and weather damage from sitting in a shed (I think) for many years inop.
I bought a whole transformer set from Matamp USA and used the OT and choke (Drakes)----- In the years since I hear that this model Drake OT isn't known for reliability in Orange amps and Electric Amps (what became of Matamp USA) now sells their USA made transformers made to their own specs.
Despite this the Drake OT in my amp has performed well for many years now.
The transformers in the OR80 are the same ones used in the OR120----exact same parts----- the OT secondary is wired differently, in the OR80, to allow the proper reflected impedance to be placed on the output tube plates---- the load is doubled (8 ohm OT tap is connected to the 16 ohm position on switch, and so on--- 16 ohm tap is not used).
So the proper OT in the OR80 is huge:

So you could get the proper type OT from Electric Amp or Mercury Magnetics----- both will be expensive.
But if you like the way your amp sounds now and the idea of an improper replacement OT doesn't bother you, then just play your amp and enjoy it...............................gldtp99


Senior Member
Here are pics right out of the box before any clean up. You know it might be one of those "if it aint broke don't fix it" kind of deals as I put it to the test last evening and this thing roars but I've never had another one to compare to so I guess I either don't know what I'm missing of don't realize what I have. It does have a nice set of Winged C's

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Gold Supporting Member
Just no way to know how it's going to sound with the correct OT vs what you have in there. Bottom line, if you're happy, don't change it!

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