Dynaco PAT 4 Pre-Amp ...A Repost with more detail


I purchased this Dynaco PAT 4 . Someone had put a volume control in place of the Input connection  (on the front of unit)
I think I found the reason it was probably done.
It controls the volume to Output 1( on rear of unit )....so I have 2 volume controls in front.
Here is my question:
I hear a hum on Output 2 but there is no hum on Output 1...
(these Outputs are for Amp hookups.)
So..... am I correct in assuming that the Dynaco was modified for that reason.??
Thanks....I know i may be stating in a confusing way.

rocky1313
There should be no hum on both outputs if the wiring was done correctly. Check the wiring to Output 2. Appears to be a missing ground connection.