Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on September 16, 2023, 04:08:15 pm

Title: Musicman 2100 RD Power Transformer
Post by: plexi50 on September 16, 2023, 04:08:15 pm

I have a 2100 RD Musicman amp that has a power transformer that gets ultra HOT! After 2 minutes the thermal unit turns the amp off.It does not blow the fuse. It has been re-capped but that has nothing to do with the power transformer. Does it sound like the PT is shot and needs replacing? I have looked around and have not found one as of today. I would think the fuse would blow long before it gets to Volcanic Lava hot! Yes it will cook potatoes as well. :dontknow:

Title: Re: Musicman 2100 RD Power Transformer
Post by: PRR on September 17, 2023, 02:02:29 pm

Replace the fuse anyway. Use the right Amps value for your local wall voltage

Title: Re: Musicman 2100 RD Power Transformer
Post by: shooter on September 17, 2023, 03:47:15 pm

Quote

Does it sound like the PT is shot and needs replacing?

sounds like something is sucking large currents through it.


have you isolated the load from the PS and see if it runs cool?
have you checked the PS rectifier to make sure it's making DC instead of passing AC?

Title: Re: Musicman 2100 RD Power Transformer
Post by: plexi50 on September 17, 2023, 06:42:52 pm

I isolated the load from the PS and it still gets super hot. I found a PT at Mercury Magnetics. The diodes test good but i will change them as well as the 390 ohm ceramics. They had +16 & -16 volts on them. The light bulb dimmed and i knew i had a problem yesterday when i first turned it on. I have to change those smaller caps as well. wrong values.