60Hz hum in soldano sp77 guitar preamp

[CJ]

"a hard tap to the front panel got rid of the last of the 60hz hum  , and tapping on anything didn't
do it [ nothing is grounded on the front panel ]  the hiss is now louder than the hum which seems to be
higher than 60hz of what is remaining"  ???


can you translate that weird canadian slang into something a gringo can understand?

 

[okgb]

Sorry Man  , gotta run to the gig , will get back to ya with a deposit
[ can't identify any " bad components , Hum left is 120 / 180 it seems ]

 

[okgb]

Hard to tell because I regrounded things and isolated points that didn't need to be chasis grounded
In testing I thought I was isolating grounds but when i actually measured one it was still grounded
[ the input jack which feed the preamp audio ] it had isolating washers so I didn't question it , but
when i took it off and checked , then reinstalled it , best the preamp has been  , not bad
if the guitar is not close to the to the amp , so I believe I made it better with good grounding BUT
allot of the problem was the isloated input jack that wasn't actually isolated [ just looked that way ]
still some 180 ish hum but it's usable now .