• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Sonic Frontiers OTs

Thanks for the help offered, especially Eli D and ticknpop for schematics.

Sorry to resurrect an old thread. But the transformers that Francois has did not go in the ST-40. They were used in the Sonic Frontiers SFC-1. They have no ultralinear taps and a single secondary connection.

Primary impedance is 5kohm with a 6 ohm load. Hammond was the OEM and produced as a custom.