Rewired the one of the secondaries on this A&R 2504 output transformer from this Steanes Sound System S311 PA head for an 8 ohm speaker.
This is very much a note to self for future reference: approximately zero other people will be interested in this.
Two bifilar winds in parallel were used for negative feedback (marked FB). Wiring them in series increased the impedance to ~8 ohms. Linking these was not my genius idea unfortunately – full credit to Tim Robbins and the work he has published on converting Australia valve PA amps.
Normally the secondaries are as follows
1 FB
2 FB (just under 2ohms)
3 0 Common
4 125
5 250
6 500
6K P-P, 25w
Paired with EL34
I’ll tidy up the wires later. Had some other stuff to do – cyclone on the way….
