hum resolved (hope it will be useful)

[ClaudioMarch]

Hi,

The subwoofer I built (described in a previous post of mine) was starting to make an annoying hum.
The connection of the ground cable to the signal terminal was loose. Once the cable was fixed, the hum completely disappeared.
I forwarded this post because it was not easy to understand the problem as everything apparently worked.
I hope it will be useful.

 

[wg_ski]

And a reminder to check the simple things first before blaming a ground loop or replacing power supply capacitors.