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Marshall xformer wiring...specs???

3/10/2006 12:28 AM
Dave McCulloch
Marshall xformer wiring...specs???
Hi guys, I am working on an amp and realized the output xformer is fried. i happen to have a Dagnall transformer sitting here that i believe is an output transformer, but I don't have any idea of the specs or pin outs...  
It says  
TXOP 00002  
Anyone know where to find the info? I am wondering whether it would work as a replacement for my Fender Pro project.  
3/10/2006 12:49 AM

TXOP - TX means transformer and OP means output. Marshall OTs are numbered TXOP something these days. I don't know what the 00002 is for, if I spot it I'll tell you. The size of it will tell you the wattage though.
3/10/2006 1:31 PM
Wire colors?
3/11/2006 12:48 AM

The Marshall transformers of recent years tend not to have wires, they have push-on terminals.
3/12/2006 5:07 PM
Dave McCulloch

Thats the problem, it's at work, I know it's an output transformer, but no coloured wires!!! It's a raw transformer with push on tabs (I have a set of bells it will fit in i think) I just don't know the specs... and of course it sayso nothing on the transformer... I tried contacting dagnall, but it isn't on their transformer listing... so i figure it's a OEM design just for marshall.
3/12/2006 11:51 PM
Tom Phillips

I have notes I made on the terminal wiring of a Dagnall P/N TXOP 00001 which is a 100W OT from a JCM900 amp. Maybe that means that your TXOP 00002 is a 50W unit.  
[Start Rant] I never understood why Marshall used different color coding for 50W and 100W output transformers. It could get very confusing if I try to guess the color of wire that should connect to each terminal of your OT. [End Rant]  
The terminals on the Dagnal output transformers are numbered. If you think it would help, I could look up the terminal numbers used for each lead on the TXOP 00001. Otherwise, itís fairly straight foreword to figure out the windings with an ohm meter. There will be three terminals used for the primary that will have light gauge wires attached. And four terminals for the secondary which will have heavy gauge wire attached. In the example I saw, all the primary terminals were along one side and all the secondary terminals were on the other side.  
3/13/2006 12:08 AM
Dave McCulloch

Thanks tom, once i get to work I'll look at it and let you know!  
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