• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

McIntosh Tranformer Rewinding

C

CountD

Super Member
Anyone get their power transformer rewound using the 'Transformer Rewinding Service' in Maine? They seem to have really reasonable prices on McIntosh transformer (power) rewinding. And if so, how did you go about unpotting the tar?

One of the power transformers are out on my MI-200 and need to get it done ASAP.

Thanks.
 
Register to hide this ad
I depotted a MC2250s power transformer. Used a hot plate and a propane torch. Posted pics in DIY
 
Melted the tar with a heat gun on one of my MC-30's - it seems that the amp had been mounted vertically, tf over heated and the tar all settled to one side with some loose chunks floating around. Hot plate is a good idea.

Murray
 
Have used TRS "Gary" for several transformers, MX110 (3), C28, MPI4, C20, and probably some I do not remember, he does good work. I am the one who asked him if he could do Unity Coupled (MC225) output transformers, he pulled one down and found it was more than his setup could do.
 
Thanks Terry - Actually I am trying to get it done before I send it to you, as I thought you wouldn't have time to do something for a couple months and I thought that this is one thing I could do (take out the old power supply which is bad, get it rewound, and then send the setup for a tuneup). I know ridiculously high voltages are involved with a MI-200 so I am not going to go farther than simple things I can test.

I am anxious to get this MI project online and working.

As far as unpotting the transformer I would like to do it without destroying the outside paint on the box, so I will have to take it easy. This is the area I need the help.

Heat gun may be the way to go for a gradual heat.
 
Found a 60s dual element electric hot plate at a garage sale and used that out doors to heat the case. The iron core and copper act as a heat sink so it takes a lot of time to get the tar to become more plastic. My heat gun ccaused the paint to discolor when i used it to speed the process so then I went to the plumbers torch.
 
I would email Gary [xfrmrs@roadrunner.com] and ask him about the case, he normally repaints the MX110 transformers after he re-pots them, but then they are usually in tired condition with scratches and rust.
 
The heat gun I used bubbled the paint on the can so I just sanded it down and painted. Not much else to do.

Murray
 
You must log in or register to reply here.
Back
Top Bottom