Super Champ XD PT?

[drewl]

Got a Fender Super Champ XD with an open primary on the power trans.
Anyone know if they have a thermal fuse in there before I try unwrapping it?

otherwise, I'll order a new one.

Thanks, Andrew

[Enzo]

The transformer has died, take it apart and look to see if there is a thermal. Either way the thing has to come out of the amp. If there is one, you may have options, if there is not, you are no worse off than now, and go ahead and order one. All you are out is 10 minutes to strip the tranny.

[drewl]

Thanks.

Enzo, everywhere I've tried to find this tranny it is out of stock.
Had my Fender dealer friend try to order one and he was told Fender doesn't have anymore, and that the amp was redesigned and uses a different tranny.

Can you confirm this, and if so know of a suitable replacement?

Thanks for your time.
Andrew L.

[Enzo]

Really? Five years and no more parts? That sucks.

The XD has all the solid state stuff the original Super Champ did not, so it has the extra PT windings for the low voltage supplies.

Have we torn into the old one to see if the thermal is there and has opened?

Looking at the circuit, you need to make +380 for B+, -41 for bias, 6VAC for heaters, and +/-20 to regulate to +/-12, and +5.

That's tough to find in one transformer. SOme PV models would cover it since they often have the low voltage winding, but then it may not have the 6v heater winding. Worth skimming through your PV Classic 50 and similar drawings. MAybe a Crate transformer of similar exists, not sure there.

[drewl]

Okay, I'll do some searching.
I know you're an authorized tech for alot of mfg's so I thought you might have the lowdown

I guess there's a newer version of the Super Champ XD?
If that's the case I'll try to hunt down a schem and see what's different.
Then there's always the possibility of finding a used one from somewhere.

The original one says there's a thermal inside, but somewhere the primary opened under there somewhere as I opened it up to see if I could find the open. Alot of times you can peel back and see the open, or the connection to the thicker wire breaks.

Fixed the coil to an Ampeg B18X horn that way this week.

[Enzo]

Did you FIND the thermal? It will be tucked down within the windings, not perched in full view.

[drewl]

I've usually found the thermal just under the outer wrapping of tape.
This one looks like it's way down under alot of windings.

With no PT readily available I decided to have another look.
I found the leads that go to the thermal fuse to the black AC hot wire, and just soldered another replacement in parallel with the open one.

So far it looks okay. We'll see when I install it back in the amp.

[drewl]

So, seven years later I have another Super Champ X2 with the thermal fuse in the power transformer blown.

I replaced it and the PT and amp are working but the trans feels warm after a couple hours.

Was this a common problem?

I see replacement transformers are available now for like $30.

Edit:. Actually Parts Is Parts lists the item as out of stock.

I'll see if they are available anywhere else.

[The Dude]

Hammond makes the 290ACX. It's supposed to be a drop in replacement. It may or may not be cost prohibitive for such a low cost amp, though. Also, I haven't used one so it may not be any better. Just pointing out its existence.

[drewl]

Cool, thanks.