PLAN B analog blog

i purchased a model 15 used recently.

i am experiencing what sounds like a ground hum.

any suggestions would be much appreciated.

i am using the doepfer d.i.y power supply #1 i believe, its the one
with 2 busboards.

 the case is made of wood w/ metal rails.

i have unhooked all other modules and tried powering the module as far
away from the power supply as possible w/ no luck.

unfortanettly this is the only analog osc i have so i cant tell if its
an issue w/ the power or the module itself.

i know its not the electrical in my room as i have brought the system
to other places and received the same results.

any suggestions will be greatly appreciated.

thanks, tony