Transformer hum

Michael Heaphy · Post by **Michael Heaphy** » 5 Feb 2023 5:51 am

Hello friends,
Just wondering...I have an older Black Box with the Vari-Z Control and an attached power supply made by Motorola. There is a discernable hum in the transformer not the Box when you plug it in. I don't really remember that in past Black Boxes I've had. Any one notice this, too, or has the power supply gone bad ?
Best Regards, Mike

Dave Grafe · Post by **Dave Grafe** » 5 Feb 2023 7:46 am

Is this hum induced in the pickup and coming from the speaker or is just the wall-wart itself making noise? The first can usually be addressed by repositioning the power supply, the second would indicate getting a new wall-wart. It might run for ages but then again it might not.

If you are near enough I would be happy to help you troubleshoot, let me know.

Jon Light · Post by **Jon Light** » 5 Feb 2023 8:40 am

I had to come back to this a couple of times because of my confusion. And I realize now, I think, that you mean that the internal transformer is physically humming. And I presume it is not affecting the signal?

No wall warts on a BB. Just the early ones with a fixed ac cord and then the later ones with the detachable iec cord.

I'll be interested in learning what it means when a transformer hums. Can't help -- sorry.