Metropoulos Forum

Can anyone tell me how to wire up two 50watt OT's? Thank you kindly!

Parallel and parallel

My 45/100 has a terminal block on top of chassis and the primaries are plaited and fed into this 'chocolate block (I suspect in 70s when one of the OTs blew and was replaced by a -139) so I kept it.

Originally plaited across top of chassis and both reds to pin 3 of inner output tubes and both whites with skip wire to outers.
Brown common to HT lug on corner of board near bias diode.

Mine does not have output selector so hard wired each 16 ohm tap to each output jack and the two jacks are linked with bus wire so the load has to be 8ohms.

What are you doing?

Can you do this with any Marshall type transformer? Then what use a 100 watt Power Transformer?

You can do it two ways. Have each OT feeding two tubes with separate output selectors. Or in parallel. With common output selector