Yamaha M-4

[unclejed613]

ok, that's just the voltage for the pre-driver board. your outputs are running at +/-80V, which is not adjustable, as it comes directly off of the bridge rectifier. the 80 V rails are what would need to be reduced to +/-32V to lower class A dissipation.

 

[djk]

No, it's like an APT (outputs run on a lower supply), except the HV tier is regulated.

To run at more than a couple of watts in class A either a new transformer is required, or one will need to design switchmode regulators to derive the lower B± without heat.