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Author Topic: Crack static on right channel  (Read 1436 times)

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Offline revolverxz

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Crack static on right channel
« on: May 15, 2017, 02:49:49 PM »
My crack amplifier started to have static sounds on the right channel after a month of use (similar to the sound when removing/inserting the headphone jack). I checked to see if the problem is coming from my headphone but the static is not present when using other amps. So far I've tried:

1. Changing /Removing the RCA cables
2. Using a new Power tube
3. Only having the power cord and a headphone connected
4. Turning off cellphone+laptop

and it still produces static. I haven't changed anything on the amplifier's circuit since I finished building it. I still haven't tried changing the input tube or cleaning its pins.

Offline Doc B.

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Re: Crack static on right channel
« Reply #1 on: May 15, 2017, 03:47:59 PM »
Try cleaning those pins next.
Dan "Doc B." Schmalle
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Offline revolverxz

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Re: Crack static on right channel
« Reply #2 on: May 15, 2017, 04:39:46 PM »
Will sandpaper work? I don't have any brushing tools or rubbing alcohol.

Offline revolverxz

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Re: Crack static on right channel
« Reply #3 on: May 17, 2017, 04:48:47 PM »
Update: I left the crack on the whole day yesterday and the noise happens less often now. I still hear it sometimes but it's more quiet than before. I'll see if my replacement tube will fix the problem.

Offline Deluk

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Re: Crack static on right channel
« Reply #4 on: May 18, 2017, 12:48:57 AM »
Push the pins through a piece of fine Scotch Brite. A combo dish washing pad can be used, one that has softened up with a bit of use a good choice. You can glue a piece inside a small tube to make an individual pin polisher. Don't go crazy, the pins have pretty soft plating. A squirt of DeOxit helps.

Offline Karl5150

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Re: Crack static on right channel
« Reply #5 on: May 18, 2017, 02:40:31 AM »
Another often mentioned pin cleaning trick is plunging several times into a "magic eraser".
Karl
Downstairs: Planar3>Eros>Stereomour II>diy OB Betsy+
Upstairs: DIY RP1>Reduction / CD5004>Seductor/SEX 3.1.1>FH3/DT770 pro/HE-4xx
Office: Schiit Modi Uber 2 / Sirius Tuner>SEX 2.1.1>µFonken FF85WK with diy subs
Garage: CA x12 streamer>Quicksand>Minimus 77

Offline revolverxz

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Re: Crack static on right channel
« Reply #6 on: May 18, 2017, 02:05:55 PM »
I have replaced the input tube but I'm still getting static/crackling noise on the right channel. Could it be outside interference causing it? I don't think it's a bad/cold joint since I have been using the crack for a month without the static/crackling.

Offline Lawrence Ho

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Re: Crack static on right channel
« Reply #7 on: May 20, 2017, 02:10:26 AM »
I have replaced the input tube but I'm still getting static/crackling noise on the right channel. Could it be outside interference causing it? I don't think it's a bad/cold joint since I have been using the crack for a month without the static/crackling.

I had almsot the issue before.
Try turn off your router or move your amp away from it.

Offline revolverxz

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Re: Crack static on right channel
« Reply #8 on: May 20, 2017, 11:27:52 AM »
Turning off the router did not help. I think it's the tube sockets. I will try cleaning them next.

Online Paul Birkeland

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Re: Crack static on right channel
« Reply #9 on: May 22, 2017, 07:49:33 AM »
I don't think it's a bad/cold joint since I have been using the crack for a month without the static/crackling.
The age of the amp doesn't preclude the possibility of having bad solder joints.  I've worked on 50+ year old gear that had flaky solder joints that didn't reveal themselves until well after production.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline revolverxz

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Re: Crack static on right channel
« Reply #10 on: May 23, 2017, 08:32:55 AM »
ok I have tried the chopstick test and none of the connections affect the crackling/static noise. Cleaning the tube sockets with DeoxIT did not help. I also noticed that the crackling isn't that loud/happens less often when there is music playing. I don't understand why this happens because there is noise even if I only have the headphone and the power cord plugged in.
« Last Edit: May 23, 2017, 08:41:15 AM by revolverxz »

Online Paul Birkeland

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Re: Crack static on right channel
« Reply #11 on: May 26, 2017, 12:07:42 PM »
It might be a good idea to try a different 12AU7.

-PB
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline revolverxz

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Re: Crack static on right channel
« Reply #12 on: May 26, 2017, 03:25:29 PM »
I replaced both tubes and still have the crackling/static. I was able to use the crack without any noise for the whole day yesterday and two days ago, but now it's back. 

Online Paul Birkeland

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Re: Crack static on right channel
« Reply #13 on: June 01, 2017, 10:20:54 AM »
I would go back to the chopstick test.  Pay careful attention to the junction of the black wires on the headphone jack; that seems to be a spot that gives builders some trouble.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man