full schematic SWR workingsman

[HutchAmpMan]

Attached links evidently you not viewed or not understand. It does not matter.
If it's not difficult specify your SWR model name from the front or back panel.

By the way Workingman 2X10C is not a TDA chip amps, it's designed in discrete technique.

https://www.talkbass.com/threads/workingmans-10-schematic.1428121/

The links were viewed and understood. As I said before, they are not the correct ones. The 2X10C is for the Working Pro which is completely different. There have been at least three versions of this amp, two (or more) by SWR and another one from Fender.

I have contacted Fender and they sent all the schematics they have, Possibly I will be able to get a complete schematic drawn up from this information and if so, will post it here.

Best regards,
Tom

[HutchAmpMan]

WM 10 Full Corrected Schematic - Discrete Version

Well, I've managed to track down all the schematic sections for the discrete WM10 bass amp. Special thanks to Jazz P Bass for the PA section.

The other two parts are the Power Supply and the FRT schematics, which are attached. Note there were some errors on the FRT schematic. This is the one with the Input, Audio, XLR and FX sections, plus the Speaker board section.

The errors were duplicate R35 resistors; the correct one is on pin 1 of IC4: B, the incorrectly labeled one is on the speaker board which is a 1 Watt 100 ohm resistor. I have relabeled that one as R39.

The other was a duplicate C27/ 47uF/35 cap which is connected to R4 and then to Ground from IC1:A pin 2. My board does not have the cap (shown as the second C25) between pin 1 and R5, it is a direct connection so I deleted this cap from the schematic. Other amps may have this cap, looks as if there were several versions prior to the TDA equipped amps.

BTW, any of these old amps need to be completely recapped or they will come back. This one had been worked on previously to me getting it and was not recapped, just had the PA and driver transistors replaced. The little C25 2.2uF Non Polarized cap in the PS section was resistive, causing a fault on the +15V supply for the op amps and also the optocoupler drive. There were other bad caps as well. There was lots of circuit board damage where a resistor melted and burned two traces and a chunk of board about 1/4" squarish. Not a hard fix with the right epoxy, replacement traces & through hole rivets.

I didn't bother renaming the "Woffer" to Woofer on the speaker board!

Best regards and thanks for all the help,
Tom

[Enzo]

Isn't that the same power amp I put up in post #11?

[HutchAmpMan]

Isn't that the same power amp I put up in post #11?

Yes, same power amp, but did not have the FRT or PS schematics.

Thanks again for providing the schematic.

Best regards,
Tom

[HutchAmpMan]

Workingman's 10 disaster update!

You know, as a technician you do have the right to decline a repair job.

Enzo, if this wasn't for a friend and longtime customer, I would have suggested that he make an extension cab out of it! It's my shop, so I can choose when I want a "project"!
Was a total pain in the A$$ to get running, but it does live again!

I tried to attach a picture of the damage when the amp was opened. Looks worse than it was, most was smoke damage. Had to replace two traces, a couple of fire damaged components, the PA transistors and the stubs of the resistor that blew when the output transistor shorted!

I told him that I'd like to know how it works for him, but not to darken the door of my shop with it again! He got a kick out of that, is a longtime customer (and friend) and the goodwill was worth it.

Tom
HutchAmpMan