ST70 power transformer

In an interesting discussion on the heat produced by the original PA060 and choke.  I posted the pic below as a possible overheated transformer.  Someone responded that Dynaco actually dipped transformers like that to reduce mechanical hum.  True??  Aesthetics are not to my taste, but if it works, who am I to judge?

Yes, I've certainly seen transformers like that in old TVs - seems it was common in the 50s/60s. One giveaway is that when installed in the amplifier, the transformer is mounted flat, as in your picture. Note that the drips in the coating are on the right side - if it had been in the amp and overheated to the point of melting the tar, the drips would run down, not sideways as they are in the photo.

-Pat

I see your point. Here's a shot of the bottom.  Still isn't visually appealing.

Agreed - it's definitely not pretty. But also not overheated. (I too much prefer powder coating the newer transformers on my builds - it certainly looks orders of magnitude better than the bitumen material they used to use.)

-Pat

I've seen hundreds of Dynaco transformer that look like that.   I've always chipped off the paint and then repainted them.
If anyone is interested I have a few brand new transformer covers for $5 each plus shipping, have them for this PA-060, some A470 OPTs (ST70), lot's of ST120 OPTs, no M125s

tubes4hifi wrote:I've seen hundreds of Dynaco transformer that look like that.   I've always chipped off the paint and then repainted them.
If anyone is interested I have a few brand new transformer covers for $5 each plus shipping, have them for this PA-060, some A470 OPTs (ST70), lot's of ST120 OPTs, and some M125 OPTs.

I'd be interested in a pair for the M125 output transformers - my oh-so-helpful lab assistant (seen in the background) managed to knock one of the transformers off the shelf after I'd powder coated them, and buggered up the covers.  The prospect of doing the body work, then stripping and recoating them ground me to a halt on the amplifier build.  It'd be easier to start from scratch with fresh covers.  Please let me know what the cost would be for a pair shipped to Watertown, CT 06795.  Thanks!


If anyone's interested, images of the powder coating process are in the gallery here: https://pmanning.smugmug.com/Electronics/M-125s

-Pat