This gives me some interesting thoughts. There are two secondary windings, = they could be layered or bifilar. If they are bifilar wound, it wouldn't ma= tter how I connected the two in series. But if they were layered, I would w= ant the start of the first secondary to be closest to the primary winding. And I'd want to have the end of the primary to be connected to neutral. Thanks for the ideas. But I think tonight I will clean the pots in my param= etric equalizer instead of tinkering with the amplifier. All this stuff tha= t's been in my closet for 20 years seems to want attention. Best regards, Bob ________________________________________ From: piclist-bounces@mit.edu on behalf of AB Pea= rce - UKRI STFC=20 Sent: Wednesday, July 3, 2019 1:47 PM To: Microcontroller discussion list - Public. Subject: RE: [EE]: Audio amplifier power supply problem This suggests on primary has been wound the opposite way to the other, such= that the line side of one transformer is against the secondary winding, wh= ile the other has the neutral side against the secondary. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .