Loud hum with no input fender Hot Rod Deville

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jshag
Posts: 9
Joined: Sat Jul 26, 2014 9:07 pm

Loud hum with no input fender Hot Rod Deville

Post by jshag »

Loud hum with no input on a Fender Hot Rod Deville.
Plug in a guitar hum all but goes away. Put a scope on B+ point and there is AC on the B+ supply.
Bias cannot be adjusted past 50mV DC

Simply replace the electrolytics?
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cbass
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Location: Between Pomona & Bakersfield

Re: Loud hum with no input fender Hot Rod Deville

Post by cbass »

Sounds like your input jack is bad
Not switching the tip to ground
Stevem
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Location: 1/3rd the way out one of the arms of the Milkyway.

Re: Loud hum with no input fender Hot Rod Deville

Post by Stevem »

Yup those jacks are for crap! One tug of the cord a little too hard and they brake and or the contacts in the jack bend.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!

Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
jshag
Posts: 9
Joined: Sat Jul 26, 2014 9:07 pm

Loud hum

Post by jshag »

Already replaced the jacks as one was bad so replaced them both with insulated switchcraft type
jshag
Posts: 9
Joined: Sat Jul 26, 2014 9:07 pm

Loud hum on Fender with no input

Post by jshag »

Now looking at the schematics the tip of jack is sent to ground with out a jack plugged in. The switchcraft jacks do not have the option to send tip to ground with out a plug inserted in at least one of them
sixstringer
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Location: SoCal

Re: Loud hum with no input fender Hot Rod Deville

Post by sixstringer »

eh? Check out the Switchcraft 12A jack.
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briane
Posts: 557
Joined: Wed Mar 28, 2007 8:41 pm
Location: seattle

Re: Loud hum with no input fender Hot Rod Deville

Post by briane »

bought the wrong jacks ehhh?

another trip to rat shack....
it really is a journey, and you just cant farm out the battle wounds
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