Yes, eliminate external wiring from the input pads on the board.
You have just the board and speaker attached together with the three wires to the power supply, so plus, minus and ground.
The input of the amp is shorted to ground at the board terminals. Any wire you had going off to the sockets are disconnected.
This allows the amp to run in total isolation on its own. With the inputs shorted it should be quiet.
You have just the board and speaker attached together with the three wires to the power supply, so plus, minus and ground.
The input of the amp is shorted to ground at the board terminals. Any wire you had going off to the sockets are disconnected.
This allows the amp to run in total isolation on its own. With the inputs shorted it should be quiet.
Have you tried rotating the transfomer around its axis or between vertical and horizontal orientation ?
Maybe in your temporary chassis its orientation was different in relation to the Jensen than now. Toroids have radiation "lobes" and radiate more in certain directions than others.
Regards, Claas
Maybe in your temporary chassis its orientation was different in relation to the Jensen than now. Toroids have radiation "lobes" and radiate more in certain directions than others.
Regards, Claas
Success!!! 
The hum is gone.
Even with removed input leads it was still humming.
So i decided to throw everything unneccessary out.
That included my speaker protection and the wires to the Front LED.
Then it was silent.
I Think the board picked up the hum through the led wires... crazy.
The Wiring was exactly the same as in my second channel, so i thought that should not be the problem.
I was wrong
Now i have to rethink some Wiring...
But i will sein this opportunity to put in my new speaker protection, that i designed
The hum is gone.
Even with removed input leads it was still humming.
So i decided to throw everything unneccessary out.
That included my speaker protection and the wires to the Front LED.
Then it was silent.
I Think the board picked up the hum through the led wires... crazy.
The Wiring was exactly the same as in my second channel, so i thought that should not be the problem.
I was wrong
Now i have to rethink some Wiring...
But i will sein this opportunity to put in my new speaker protection, that i designed
Thanks @ Spe@kerBox
I don't give up that easily.
@ Mooly
Yes, you are right. It's really odd.
Maybe the hum was introduced via the ground lead of the led, but that's really unlikely.
Or it came from one of the leads of the speaker protection.
It has one lead to positive DC rail and one to the related AC voltage before the rectifier to sense power up and power loss.
Maybe this circuit got slightly damaged by my polarity fault.
Seems to be more likely
I don't give up that easily.
@ Mooly
Yes, you are right. It's really odd.
Maybe the hum was introduced via the ground lead of the led, but that's really unlikely.
Or it came from one of the leads of the speaker protection.
It has one lead to positive DC rail and one to the related AC voltage before the rectifier to sense power up and power loss.
Maybe this circuit got slightly damaged by my polarity fault.
Seems to be more likely
Hello my fellow diyers.
I just wanted to inform you that it seems like package coming in from Italy to Us is being affected by the Covid19. I've ordered my chassis on May 17th and it is stuck in Germany. I just called the Fedex and the representative said that i may stay there indefinitely. This is an act of the nature/noone at fault. But I wanted to share my experience with you all.
Happy buillding, and we will beat this virus together.
I just wanted to inform you that it seems like package coming in from Italy to Us is being affected by the Covid19. I've ordered my chassis on May 17th and it is stuck in Germany. I just called the Fedex and the representative said that i may stay there indefinitely. This is an act of the nature/noone at fault. But I wanted to share my experience with you all.
Happy buillding, and we will beat this virus together.