Best place to rebuild a vintage transformer?

[toneman335]

Can you provide contact information for someone that would do a great job in rebuilding a Fender blackface transformer to original specs?

[JDJ]

Mercury Magnetics has a reputation for doing a good job, but I have no personal experience with that service from them. I did speak to them once about doing it, and they were impressive on the phone. I just bought a replacement and boxed the original.

[mark norwine]

I'll catch hell for this, but I worked at a transformer manufacturing facility for 6 years:

With this size transformer, there's no such thing as a "re-wind".

Dissection of a transformer:

1.) remove the bells & set them to the side. They can be reused.

2.) the lams get cut off with a bandsaw because they're either welded or glued (or just plain rusted) together. Can't re-use those! And why would you want to, anyway?

3.) the 10 cent bobbin (if bobbin wound) or the former (if paper) is "chucked"...i.e. mounted on a freely-rotating arbor.

4.) the wire......miles of it......thin & intertwined, is pulled off. It is virtually impossible to salvage it, and even if you could get it off in one continuous length, you'd never get it back on. Not happening. I call BS to anyone who says otherwise. It goes out for recycling. And remember: it's bad to begin with! That's why you're having it "re-wound" in the first place.

After disassembly, what are you left with? 75 cent end bells & a 10 cent bobbin.

No, folks, there's no such thing as a "re-wind". There's only "Make a new transformer using old end-bells"

The only reason for taking a transformer of this size apart is to "reverse engineer" it so that you can learn the specs & make new units to those specs. I assure you: MM already knows the BF specs and has no need to take yours apart.

My suggestion: Forget the notion of rewinding and just buy any one of the numerous, high-quality aftermarket transformers that are commercially available.

[soldersucker]

I'll catch hell for this, but I worked at a transformer manufacturing facility for 6 years:

With this size transformer, there's no such thing as a "re-wind".

Dissection of a transformer:

1.) remove the bells & set them to the side. They can be reused.

2.) the lams get cut off with a bandsaw because they're either welded or glued (or just plain rusted) together. Can't re-use those! And why would you want to, anyway?

3.) the 10 cent bobbin (if bobbin wound) or the former (if paper) is "chucked"...i.e. mounted on a freely-rotating arbor.

4.) the wire......miles of it......thin & intertwined, is pulled off. It is virtually impossible to salvage it, and even if you could get it off in one continuous length, you'd never get it back on. Not happening. I call BS to anyone who says otherwise. It goes out for recycling. And remember: it's bad to begin with! That's why you're having it "re-wound" in the first place.

After disassembly, what are you left with? 75 cent end bells & a 10 cent bobbin.

No, folks, there's no such thing as a "re-wind". There's only "Make a new transformer using old end-bells"

The only reason for taking a transformer of this size apart is to "reverse engineer" it so that you can learn the specs & make new units to those specs. I assure you: MM already knows the BF specs and has no need to take yours apart.

My suggestion: Forget the notion of rewinding and just buy any one of the numerous, high-quality aftermarket transformers that are commercially available.
Thanks for the reality check i too bristle when being sold an amp with "rewound" trannies.

[jay42]

:agree This ought to be a sticky.

[SatelliteAmps]

For what it is worth, the original end bells usually will fit on a vintage spec'd Mercury, so you can just swap the end bells. (Or ask for one with no end bells, might save a few bucks.)

[JDJ]

Well, the cost of rewind was about 2.5 times the cost of a replacement. That's why I went that route. Evidently, it was correct for other reasons.

[Chris Scott]

... and I'd really be curious as to why.;)

Great post Mark!

(and the truth shall set you FREE!)

[pula58]

why put the old end bells back on? If you're gonna sell the amp it would be unfair to claim it is an original tranny.

[SatelliteAmps]

why put the old end bells back on? If you're gonna sell the amp it would be unfair to claim it is an original tranny.

For the same reason as getting the original rewound. It is the same thing, just cosmetic.

[brad347]

why put the old end bells back on? If you're gonna sell the amp it would be unfair to claim it is an original tranny.

for looks? You don't have to lie when you sell it.

[SatelliteAmps]

for looks? You don't have to lie when you sell it.

Some people like to retain the looks, and also don't lie. Some people put new cap's inside of old ones to retain the look. Same thing.

[57special]

:agree This ought to be a sticky.

+1.

[Roundtone]

+1.

+1.