LuDEF

With Supreme grade transformer, blame is to be put on that shiny pot, with very low heat emissivity.
Solution: Paint it black 😈
or, listen to the music and don’t pay attention to those insignificant issues.

DC offset is mostly related to the BC564 temperature.
Solution: DC servo

As for high temperatures, I will have an implementation of Babysitter, based on Mark Johnson’s design.
 
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small buggers - use bigger sionks if you are not happy with temperature

offset - not biggie

I believe with my pcbs it's more stable, but who cares about 50mV

Donut - 65C is showing how Supreme it is, with measly 160VA of load
65deg is not acceptable for a traffo. Should be 40deg or less. 50 at a push, but really that's still not good enough. It's too small
 
taking in account that this potted xformer can't be "shorted" through mounting screw, so that possibility is outa suspicion

power off, cut off rails from one channel, so Donut/cap bank being loaded with just one channel

leave it to temp equilibrium and inform us what's temp of Donut then
 
Take in the account temperature inside case. With heatsinks at 55 degrees and lid on, inside must be 40-45. So, transformer is only 20 -25 degrees above ambient. Polished pot also doesn’t provide much heat removal through radiation. I think that 65 degrees is expected under such conditions.
 
taking in account that this potted xformer can't be "shorted" through mounting screw, so that possibility is outa suspicion

power off, cut off rails from one channel, so Donut/cap bank being loaded with just one channel

leave it to temp equilibrium and inform us what's temp of Donut then
Hi ZM. With only Left channel connected to the PSU and after 1 hour of warming up, the pot of transformer was just at about 30 degC. Same with just the Right channel powered - the pot at about 30C after an hour. With both channels powered and 1 hour of heating up, the pot of power transformer at about 35C, after 1,5 hrs - 40C, after 2,5 hrs at 50C. Diod bridges now are at 55C, heasinks at 50C.

What would you say? Perhaps tombo56 is correct that this is expected?
The shiny pot was at 65C after the full day of opperation, some 8 hrs perhaps.
 
Well yes, Supreme was a dissapointment. Did not expect that from Toroidy 🙁 I’d really better go with the regular one and a cheap chinesse black pot as I did for my M2X.

But well - babysitter (or two) could be the next thing to build 🙂 I have enough amps now 🙂
 
The new monoblock chassis sets look optimum for this build. In this case, I'm glad that I've been slow to build my boards into a chassis. The Triad Magnetics transformers have performed very well so far in my Sony VFET external PSU, and the re-build of my M2x. I'm going to stick with those.