Hi Miguel

> i just installed a new DIY kit 2, the cheaper one, inside a new frame.
> i get an annoyimg electrical drone when i connect the output of any
> module installed there to my mixer.
> the red leds of the bus board and the modules are OK.

Try connecting an earphone or headphone with 3.5mm jack to the output of
a module (and do not connect anything else). You will hear of course
only on side of the earphone, but it may show you whether the hum is
there or not. If it is there, something is wrong with the diy kit (or
how you connected it). If the hum is not there, then you have a problem
with the electric relation of this A-100 frame and the mixer.

Florian