Restoration for Mark II

[James]

I finally decided to fix up my old Mark IIB, as it's not exactly in good condition, as you can see here.

So far, I've managed to clean all the dust and junk out of the insides.

Everything on the inside looks fine, no fried things or anything like that.

It's all original as far as I know, and the filter caps seem to be in fine condition. No buzzing at all.

The transformer might need some attention, it heats up a fair amount pretty fast, and I'm not sure if that's normal. (because it never heated up at all before I changed all of the tubes.) Like I said before, it has a loose socket, but that doesn't appear to be the problem..I've used it for about three hours total since the tube change without bad smells or any problem.

The transformer is a rusted old thing, and it has this black stuff coming out of the top, though I've seen that with alot of IIC amps, so I'm guessing it's not a problem (?)

One other thing is that when I used the treble shift, it doesn't affect the sound at all? what is it supposed to do exactly?

Anyone have suggestions on restoring it?

Thanks

 

[Boogiebabies]

Your new tube may be drawing more than the previous set and making the PT work harder. I would check the plate voltage and check the bias with a bias meter. Some PT's get hot. The treble shift should only work on the lead channel. The pull bright on Vol 1 is a 180pf cap for the clean.
As far as rusted PT's and OT's, the only thing you can really do is clean them with a toothbrush, denatured alcohol and a rag.
When you knock off all the rust it is best to just paint them with shellac to seal them from oxidizing again. Once the rust gets through the laminations it is a good possibility that the core/Iron is rusting as well. I have seen a few of these, but they are uncommon and were abused and improperly stored.

In most cases it is surface rust and can be cleaned and sealed with years more of use ahead of them.

Schumacher dipped some PT's very well with resin. Most were just potted inside and the exterior was left to the elements.

 

[James]

Thanks

I managed to clean off alot of rust from the OT, and I checked all the caps.

It looks brand new and sounds even better, but I tried using the same type of tubes it had before, and the OT still gets pretty hot.

I'm just worried about hooking it up to my 4x12 again