Bustificated tube amp...anybody help a brutha out?

[Default]

One thing I did notice is that the rectifier tube seems to be a little...cooked. Not well done or anything, but a lightly sauteed with some dark discoloration to the tube around the base. Is that normal or could this potentially be the problem?

Ok, bad power tube maybe? The other tubes don't have that same discoloration?

 

[Hammer]

Nah, they don't and it looks like the tubes were fine. The output transformer had blown and since it appears to be a PITA to get one for this amp and since I only paid ~$200 for it...it's taking a dive off of a very high roof...quite literally. Should make a pretty big bang. :lol: I have since appropriated a 1991 Peavey Classic 50 212 to go with my Fender HRD 212. OMG, that Peavey is heaven in a box. :shock:

 

[Default]

Replacement for a fender twin should work

 

[Hammer]

Really? A Fender Twin output transformer will work in a B-52 AT-212? If so, that'd be frakking awesome. The tech I took it to told me B-52 used some special size/type of OT in that amp and it's more expensive to obtain one than the amp is worth.

 

[capnjuan]

Link to Mojotone ... for a Twin Reverb 4X6L6 ... $85 plus shipping.

 

[Default]

Really? A Fender Twin output transformer will work in a B-52 AT-212? If so, that'd be frakking awesome. The tech I took it to told me B-52 used some special size/type of OT in that amp and it's more expensive to obtain one than the amp is worth.

Even an ultra linear ot shouldn't be insanely expensive. Mercury Magnetics are >$200, but why bother for a 200 buck amp? cj has the right idea.

 

[capnjuan]

Don't know what the B-52 has but the Mojotone OT has 4, 8, and 16 ohm taps ... switchable is a nice thing 8)

 

[Hammer]

Bah! Mojotone out of stock! Boo. The hunt is on though!

 

[capnjuan]

Weber carries a Twin/Twin Reverb OT. Scroll down to W022889. Click for details. $58 plus shipping but limited to 4 ohm secondary.

Weber also sells Heyboer and Mercury Magnetics but they are up-priced; scroll down on the left.

 

[RussB]

Nah, they don't and it looks like the tubes were fine. The output transformer had blown...

I wish I could look over that amp. I would bet dimes to dollars the the OT is NOT bad. I would wager that either the rectifier tube or a power tube is bad. How can a tube "look fine" A shorted tube looks just like a good tube. Did you measure the resistance of the secondaries of the OT, what are your readings?

Which fuses are blowing? Do you verify that the fuses are bad by checking with your DMM set to continuity check?


Put new fuses in, remove ALL the tubes, turn the amp on.

If the fuse holds, turn it off and install the rectifier tube

Turn it on again, does the fuse hold?

If so, turn it off and also install the power tubes.

How are the fuse's doing?