#1
I plugged in my old silver tone tube amp the other day and its clearly broken. Once it warms up it staets to hum very loudly. The guitar cant be heard at all until the volume is turned to maximum. Even then it is very faint behind the hum and its very distorted. I just soldered the speaker back to the leads. Oh yeah, when i turned the amp off the first time the hum raised in pitch before it went quiet. Any ideas please?
#2
I would recap it. is it at 120hz? if so, it is a dead give away.
WTLT 2014 GG&A

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alright "king of the guitar forum"


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nope i am "GOD of the guitar forum" i think that fits me better.


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youre just being a jerk man.


***"What Trashed Hoards"*** (updated 2016-11-27)
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Last edited by trashedlostfdup at Nov 27, 2016,
#3
Quote by trashedlostfdup
I would recap it. is it at 139hz? if so, it is a dead give away.

Those caps are some 50 years old. It worked fine about 15 years ago, and the tubes still light up.
Last edited by geo-rage at Nov 26, 2016,
#4
Quote by geo-rage
Thanks trashed! 139hz are you talking about the sound wave the hum makes?
Those caps are some 50 years old. It worked fine about 15 years ago, and the tubes still light up.


typo. lol i was on my phone and aurocorrect fucked up. 120hz.

the 120hz is the frequency of the hum of bad caps. as opposed to the 60hz which is (to a degree) normal.

those caps are way too old. In my older amps, i don't really like going beyond 20 years.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.


***"What Trashed Hoards"*** (updated 2016-11-27)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#5
the caps have nothing to do with the tubes, they filter out the AC current after the rectifier. they do indeed age.

tubes lighting up is a good thing.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.


***"What Trashed Hoards"*** (updated 2016-11-27)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#6
Obligatory: Working on amps even when off and unplugged can cause lethal voltages to go through your body. Take it to a tech if you are not comfortable with working around that.
#7
Quote by Will Lane
Obligatory: Working on amps even when off and unplugged can cause lethal voltages to go through your body. Take it to a tech if you are not comfortable with working around that.


WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.


***"What Trashed Hoards"*** (updated 2016-11-27)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#8
Guess i'll have to learn how to discharge caps. In the meantime im trying to source caps. Any suggestions? Mouser? Tubesandmore? I found a schematic that lists all the caps for this model. They are described as .003mfd 600v, for example. Im assuming that mfd stands for micro farad and not millifarad. I believe the funny uf(as websites use) stands for microfrad and is interchangeable with mfd