I have a Class-A amp who needs about +/-16V and 4 amps as idling current. With an ordinary design with 60 000 uF for each +/- the trafo have 700VA 16V I have to much hum in the silent parts of the music. Can some one give me tips for nice power supply designs?
It is a single end config. If I change to lover current there is no problem with hum, very low hum. I have already tested different config. And I use a good one. I only need a good power supply who meets the current in idle 4 amp.
try using an rCRC PSU or better still rCLC PSU.
the r= transformer resistance.
C=smoothing capacitance. split into two stages.
60mF sounds about the minimum for a 4A bias current.
I reckon you should add an extra stage giving 0r2, 20mF, 0r2, 60mF. and see if that helps.
But, have a thorough look at your power grounding and ensure it is separated from your signal grounding.