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Replacement Transformers for HD-130

I have a HD 130 with a defunct power transformer. I've read through some old posts on this forum and have come across a few places that used to produce replacements. I searched Mojotones website and couldn't find anything on there so I reached out to them. The Music Man transformers are long gone from there according to them. Didn't sound like they planned on getting any more either.

Im skeptical to buy the Mercury Magnetics parts due to what looks like some QA issues according to some other users here. Dont want to spend nearly $500 on replacements for both transformers to have them show up and not work. Thats also most of the cost of just buying a whole other amp.

My question boils down to is there anywhere to get replacement transformers these days that isnt going to cost damn near the value of just buying another amp?

mm210's picture

Wish I had an answer for you.

Wish I had an answer for you. Maybe if Lars pops in he can steer you right or Ed Goforth. they are more in the firing line right now as I don't do a damned thing any more. I have a 130 watt chassis that the transformers SHOULD be fine it but it's a complete amp that I'd really hate to bust up. Mike.

bill_moore's picture

MM can build one!

Yes, they are pricey, I had them build one years ago for a Fender Champ 25. I think they unwind the old to build an exact match.
The amp had belonged to my nephew, (no longer with us), so I fixed it to give to his cousin.


Hey thanks for the replies!

Hey thanks for the replies! The forum seemed pretty quiet these days so I wasn't sure if I'd really hear anything back.

Definitely don't want anyone cannibalizing their own gear for my sake. I figure at worst case I'll just have to buy another amp.

I honestly hadn't even considered reaching out to Music Man to see if they could offer anything. Figured they were out of the amp making business. Are you saying you had to send them in the faulty parts and they basically just repaired them?


Well I reached out to Music

Well I reached out to Music Man who basically said they handed off all production of the transformers to Mojotone and I should contact them so I guess thats a dead end. They did suggest contacting Markbass who was the company that designed/manufactured the reproduction models a few years ago. I did some reading around an apparently one of the big changes to the design they made was using different transformers from the original models so I'm not sure if that would even work. Either way, I emailed Markbass asking if they could assist in getting the parts so we'll see what happens.

bill_moore's picture

I was talking about Mercury Magnetics.

In my reference to MM above, I was talking about Mercury Magnetics. They unwind the thing, and then build an exact clone. Not cheap, but very good work.


Tube Amp Doctor may have it

Happy New Year everybody!


It would appear that TAD supplies a universal MM 'large power transformer' replacement for all 100/130/150W models.

That's all I've got.

Lars Verholt



Figured I'd give an update on this! Just got my amp back from my tech with one of the TAD transformers in it and its running as good as ever. Though, when the last one gave out it blew both speakers. One speaker was reading 0 Ohms resistance and the other had around 1k Ohms resistance. Not sure if that's a normal occurrence when a transformer goes bad but was unexpected. I'm wondering if one speaker had gone bad without me noticing and I was playing with only one working for some time which caused the issues to begin with.

Anyway, thanks for all the feedback through this! Seems like TAD is the way to go with these parts!

mm210's picture

Good to hear it's up and

Good to hear it's up and running. Sometimes it gets exciting fixing stuff that hasn't been MADE for 30 years! Mike.

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