5e3 Ground Issue

Roscoe1983

TDPRI Member
Joined
Sep 4, 2022
Posts
6
Age
39
Location
Montana
Hey all,
I built a tweed 5e3 for another fella and it left my shop sounding great. The only mod was that I built it as a 2 input amp, not the usual 4 input. However, after shipping to him, he is experiencing a loud hum. More about the hum below:

-Hums at all volumes.
-Hums when no instrument is plugged in.
-Hums on both channels with instruments plugged in.
-Hum stops when an instrument is plugged into each input at the same time; i.e. a guitar and a bass.
-I had him check the contact point on the input jacks to ensure they are shorting correctly and they are.

Just hoping someone out there has heard of this before. Thanks!
 

dan40

Friend of Leo's
Joined
Aug 19, 2015
Posts
2,937
Location
Richmond Va
It may have taken a knock during shipping. Has he tried replacing the tubes to see if one has been damaged? Is he seeing any signs of redplating on the two 6v6's. If the tubes all check out fine, I would guess that a solder joint or ground connection got knocked loose during shipping.
 

Roscoe1983

TDPRI Member
Joined
Sep 4, 2022
Posts
6
Age
39
Location
Montana
Hey thanks for the reply. He purchased tubes separately but I asked him to try others. I believe he purchased some new old stock RCA's. No red-plating reported. I am guessing it is around the inputs so I will have him take a quick photo of the area. Thanks again!
 

dsutton24

Doctor of Teleocity
Joined
Dec 29, 2010
Posts
11,193
Location
Illinois
It sure sounds like the shorting jacks aren't shorting like they should. If it worked properly when you shipped it there must have been some kind of physical damage due to shipping, packing, unpacking etc.

Is there a possibility that the other guy is doing something weird like using a cheater plug, or plugging the amp into a faulty outlet?
 

schmee

Telefied
Ad Free Member
Joined
Jun 2, 2003
Posts
21,873
Location
northwest
Did you test it enough to really know if it hums?
Do you have gut pics?
Did you do the grounds per the Fender scheme?
 

Powdog

Tele-Holic
Joined
Jul 31, 2009
Posts
573
Age
60
Location
Cool, CA
Sounds like a jack issue. Just cause the shorting lug looks ok doesn’t mean it is. I’ve had to replace Switchcraft jacks for lesser sins.
 

2L man

Tele-Afflicted
Joined
Nov 23, 2020
Posts
1,784
Age
62
Location
Finland
If other volume pot adjust the hum volume it is that half input circuit or that half triode circuit failure.
 

Roscoe1983

TDPRI Member
Joined
Sep 4, 2022
Posts
6
Age
39
Location
Montana
Thanks for all the input everyone. I’ll get gut pics and we will try some chop stocking and inspection. I’ll be back to close the loop on this when I have more info. Any other advice/thoughts etc. are greatly appreciated.
 

Paul G.

Friend of Leo's
Joined
Mar 17, 2003
Posts
4,326
Location
Rhode Island
Are they Switchraft type jacks -- 12A shorting? If so, make sure they are tight as the ground is being made through the body of the jack. If they are Cliff-type, check the ground wires.
 




New Posts

Top