Power Transformer - Rivera-era Fender Concert

[Tone Meister]

Looking for a replacement power transformer for a Rivera-era Concert. Original Fender part number 018302 stamped on the housing. The only schematic I've found shows an import PT on the drawing, but the amp I have doesn't have anything but the basic domestic US taps. The parts list included with the lo-res schematic calls for the same part number (018302). Also, the amp I have requires a 2.5A fuse but the schematic calls for a 3A fuse. Small details I know, but I figured I'd point them out before someone else did.

Screen printing on the amp's chassis at the power cord indicates 120V ~ 60Hz, 165W @ 1.8A. It's pretty clear from this screen shot of the transformer section of the schematic that I have a different PT in this amp.

Full schematics are attached.

[Jazz P Bass]

Fellow member Drewl had this issue a while back: Fender Concert Power trans replacement - AMPAGE Forum

Hod Rod Deville tranny should work.

Or you may want to contact Allen Amps.
Allen Amplification - Parts Order Page

[Tone Meister]

Wow, good stuff JPB. Do you know how easy that was to overlook? Now my concern would be the DC voltages. To confuse things, the schematic doesn't list any high voltage numbers. Both the Concert and Deville are SS rectified.

The replacement PT for the HRD produced 450 rectified DC @ 240 mA and the replacement for the Concert produces 420 @ 240 mA after rectification. The mounting centers are quite different though, so I will measure the one I have this morning and wait to see if anyone else has anything to add. Thanks JPB.


https://www.cedist.com/products/P-TF41752

https://www.cedist.com/products/P-TF22814

Does anyone know what Drewl ended up using?

[Jazz P Bass]

Google.

[Enzo]

Tonemeister, please look at your schematic. I downloaded yours, and while the part you highlighted with the multiple voltage taps was on it, that was the export transformer. The main body of the schematic shows the 18302 transformer wired as the 120v system. The schematic shows 2.5A fuse. Ignore the export sub-drawing, just look at the main schematic. Look to the left of what you highlighted, past the bridge rectifier, and there is your USA transformer circuit. The export version of the transformer is on there only for the convenience of those having that style.

The 1.8A stuff is about mains draw.

Your schematic has DC voltages on it, though tough to read. Looks like 475v at the standby switch, so we can calculate what the AC has to be.

41752 is the PT for the '93 Concert Reissue, might take a little rewiring, but ought to work.

[Tone Meister]

Thanks Enzo, you're exactly right and I had seen that after studying the schematic closer. However, the owner has decided to shelve the project for now because the amp needs a good bit more than just a new PT. All of the filter caps in the doghouse are way out of spec as well as a litany of other issues that add up fast. The wiring looks like a bird's nest inside the chassis, so troubleshooting any further issues might prove a challenge.

Boy, I got to get better at reading the minute details on these schematics. Details, details, details ...