Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Solid State => Topic started by: lego4040 on January 22, 2018, 11:09:38 am

Title: Bogen MT 250C transformers
Post by: lego4040 on January 22, 2018, 11:09:38 am
So we just upgraded our Firealarm PA system and they have huge Bogen amps in them. I upened one up and took the PT and OT out. These are huge and after researhing codes it shows these are Woodward-Schumachers. These are where used in many amps, especially Fenders. Maybe build a bass amp, the ot has a 8 ohm secondary too. I really didnt reaserch much, i just didnt want to spend to much time. I have another one I didnt strip and a whole rack of Altec Lansing
Title: Re: Bogen MT 250C transformers
Post by: sluckey on January 22, 2018, 11:19:50 am
I guess since this is in the SS forum that the amp is a solid state amp? If so, I would put the transformers back in the amp and reconnect them. They are worth nothing to a tube amp project.
Title: Re: Bogen MT 250C transformers
Post by: lego4040 on January 22, 2018, 12:35:07 pm
These were out of a solid state amp, the pc board does have 9 pin sockets for tubes but not being utilized. If I had a boat Id use the PT as a mooring. Thanks Steve
Title: Re: Bogen MT 250C transformers
Post by: PRR on January 23, 2018, 12:11:21 am
If they are audio amps, swipe the whole amp.

Transformers are just dingy-anchors without the audio crap. And once broken-up, they never seem to get used.

The "9-pin" is for a balanced line input transformer.

https://www.bogen.com/products/pdfs/powerampspdfs/MT250Dm.pdf

Two lumps each. One makes 40V AC CT to rectify out near 28V DC. The other is a 3 Ohm(!) CT winding to a bunch of speaker/line impedances. (And evern here: it wudda been best to break the output strip off the chassis still attached to the transformer; you would not be able to sort them later without the schematic.)