PT Replacement Red Knob The Twin

[Darrin]

Hello all,
New user, thanks for any info you can provide. I have a 1992 red knob 'The Twin' with a dead primary in the power transformer. Can anyone direct me to a replacement or give me the voltages of the secondaries? I've had no luck with Fender directly, and am striking out looking for an aftermarket PT. Thanks in advance, Darrin.

[Prairie Dawg]

Hello all,
New user, thanks for any info you can provide. I have a 1992 red knob 'The Twin' with a dead primary in the power transformer. Can anyone direct me to a replacement or give me the voltages of the secondaries? I've had no luck with Fender directly, and am striking out looking for an aftermarket PT. Thanks in advance, Darrin.

You might want to check out Antique Electronic Supply. It'll be a good idea to get the Fender part number and compare the schematic to the pic of the transformer.

[Jazz P Bass]

Fender the Twin PT

I believe the part# is 026477.
You may want to "open up" the transformer & look for a fusable link that is open circuit. (carefully cut back the tape that is covering the windings)
Sometimes they install underrated links & they open under normal conditions.
The only schematic I could find had a bad scan.
Link: http://www.schematicheaven.com/fenderamps/the_twin.pdf

[Darrin]

Schematic and part list for red knob 'The Twin'

Thanks for all your help, I'm definitely on the right track now. Here's a good qualtiy schematic and parts list for anyone needing it.

[ThermionicScott]

I'd roughly estimate the HT secondary voltage at 340VAC (170-0-170), the brown secondary at 110VAC.

I can think of a couple ways to re-engineer the amp for a more traditional Fender PT (including the 1/4-power mode), but it's probably best to wish you luck in finding the correct replacement. Maybe search for junked ones?

- Scott

[Darrin]

The Twin PT fix

Hello,
Thanks for the info. I have performed surgery on the PT and found the thermal fuse but have yet to fix it. I'm certain this is my problem because when I short the leads I get a reading of 2 ohms on the primary. Should this attempt fail, and If I'm unsuccessful with the search for a new one, I'll be contacting you for the mods. Thanks again, Darrin.

[Jazz P Bass]

PT Thermal Fuse

If everything checks A O/K on the amp, just remove thw failed thermal fuse & solder in a jumper.
Link:http://www.tubesandmore.com/