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RE: Transformer Orientation

Posted by Triode_Kingdom on May 31, 2025 at 10:15:01:
"As it turns out L3 was picking up radiated fields from L1 and a 90� rotate of L3 made the earth flat again."

That's exactly what I said - "The first choke in a choke input filter will generate a large AC field that can couple to any nearby choke..."

This is why I don't use choke input filters in audio equipment. I once miswired a CLC filter in a high-gain guitar amplifier, accidentally leaving out the first small cap. The buzz from the choke was everywhere. I'll bet that if you had added even a small capacitor at the input to L1, maybe only 0.47uF or 1uF, the problem would have disappeared. Voltage spikes at the input terminal of a rectifier-driven choke can be huge.