Low staticky crackle on right channel (solved)

Julyan9 · 7386

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Offline Paul Birkeland

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Reply #60 on: July 17, 2018, 03:49:13 AM
OK, well that narrows down things a lot.  This tells us that the wiring from the input jack to volume pot, volume pot to 12AU7, and 12AU7 to 6080 is all doing OK.

How do the pins look on the 6080 tube?  These are all old stock tubes, and sometimes a very heavily oxidized tube pin can be a little noisy. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Julyan9

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Reply #61 on: July 17, 2018, 04:38:38 AM
OK, well that narrows down things a lot.  This tells us that the wiring from the input jack to volume pot, volume pot to 12AU7, and 12AU7 to 6080 is all doing OK.

How do the pins look on the 6080 tube?  These are all old stock tubes, and sometimes a very heavily oxidized tube pin can be a little noisy.

Maybe this is a good thing? Still the potential cold solders tho.  I had 6080 arrive in mail, (JAN 6080WC) and with that on the amp, i don't hear the sound anymore. What I was wondering if I slightly tap the tube, it only makes a sound on the right channel. Why it doesn't affect both? I don't want to jinx it and will see for a couple of days maybe if the sound returns. Not sure if its just placebo but I think I liked the sylvania 6AS7G better than this tube that I got now. This cost like 4 euros so not a big deal, and it was mainly for counting out the 6AS7G.

I have used some "pro clean"(sort of de-greaser) on the tube pins but that didn't help. I tried with some scotchbrite but that wasn't very successful either. I think I get some fine steel wool and some contact cleaner and see if that helps! The pins look pretty ok and clean to me as is. Its just hard to think that the tube could have been making that noise.
« Last Edit: July 17, 2018, 05:21:14 AM by Julyan9 »



Offline Paul Birkeland

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Reply #62 on: July 17, 2018, 08:36:29 AM
Yes, nearly all 12AU7 and 6080 tubes we've encountered that made some noises while running quieted down after a few long periods of use.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Julyan9

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Reply #63 on: July 17, 2018, 09:04:18 AM
Yes, nearly all 12AU7 and 6080 tubes we've encountered that made some noises while running quieted down after a few long periods of use.

I kept it going for the 50h straight but it didn't help.
Ill try and clean the 6AS7G tube tomorrow and see if I can get that to quiet down also. I just have a hard time believing this all could have been caused by the tube. Month of soldering the circuit over and over at least I learned where every component is :D I'm keeping my fingers crossed.



Offline Julyan9

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Reply #64 on: July 17, 2018, 11:20:14 PM
I think this can be marked as solved. Thank you very much for your time and effort in helping me with this issue.
What I have been experiencing with the new tube is hum on right channel but that is another story. If I lift the amp from the table the hum stops. There was no hum all day yesterday so there is the next thing for me to tackle! (flex)

Edit:
So I got the 0000 steelwool and cleaned the 6AS7G that came with the kit. The right channel still crackles with that tube. I think its not as bad as it was before. Maybe I just ditch the tube all together and just use another tubes and see if they are doing any better.
« Last Edit: July 18, 2018, 06:08:44 AM by Julyan9 »



Offline Paul Birkeland

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Reply #65 on: July 18, 2018, 06:33:52 AM
Be sure all your hardware is nice and tight!

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Julyan9

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Reply #66 on: July 18, 2018, 07:07:19 AM
Be sure all your hardware is nice and tight!

Have to tighten everything down again. The new 6080 I got that is making the hum sometimes, it feels like the tube is vibrating so much that it is making the hum that way. This is only present when the tube is warming up though I think. The 6AS7G even after cleaning the pins still make the crackle.

Edit:/

Got a Thomson-csf 6080WA today in the mail and its dead quiet.

I have used the other tubes for a while and decided to give the 6AS7G another chance. Still no dice. Seems like that was the problem almost all the time at least.
« Last Edit: July 20, 2018, 09:30:12 PM by Julyan9 »