Build the Mark Levinson 23.5 from schematic?

Hello Whitesnake, I have a ML 23.5 with the boards very repaired and they are no longer in good shape, I seem to remember that something was not right in a channel and the protection was acting. Do you plan to sell these new boards? It could be a solution to a problematic power stage that was difficult to work with and adjust to the circuits, it was not a reliable design. Thanks
 
I dont have any 100hz noise, only 50hz and its harmonics 150, 250 ...
I refer this grey plank which is the GND.
 

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At the amp’s LS output sockets ?
If so, that’s totally wrong, it should be a flat noise floor with minimal signs of 50hz.

That’s why I ask you again to make scope pictures in AC mode on your 2 big and the 2 slightly smaller blue caps, to make sure they are o.k. all four. That would be my first thought as being the cause.

Hans
 
Hello whitesnake,
I assume that you are making the measurements with the heatsinks+ PCB disconnected from the chassis?
We found out with Hans that there was a lot of oscillations if the chassis was not connected to the heatsinks. One extra cable is needed for that.