[sdiy] Magnetic interference: opinions ???

[harry]

Hi Kids:

I have a Hex Fuzz that I just put in a rack. It gets magnetic induced
hum from other
AC powered units in the rack.  The rack is totally electrically isolated
from the hum
sources... it IS magnetic induced.  Power down those units and the hum
goes away...
or move the receiver... hum goes away..

Should I
1) Shield the receiver
2) Sheild the sources
3) change the AC power supplies to offboard units or other types (toroid
???)

All boxes are aluminum... I can't find any steel enclosures...

The power supplies in question are potted brick supplies +/- 15V @ 100mA

made by Intronics  (new old stock... 20 years ???)

Thanks for the tips

H^) harry