Crack static on right channel

[revolverxz]

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.

 

[Doc B]

Try cleaning those pins next.

 

[revolverxz]

Will sandpaper work? I don't have any brushing tools or rubbing alcohol.

 

[revolverxz]

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.

 

[Deluk]

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.

 

[Karl5150]

Another often mentioned pin cleaning trick is plunging several times into a "magic eraser".

 

[revolverxz]

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.

 

[Lawrence Ho]

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.

 

[revolverxz]

Turning off the router did not help. I think it's the tube sockets. I will try cleaning them next.

 

[Paul Birkeland]

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.

 

[revolverxz]

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.

 

[Paul Birkeland]

It might be a good idea to try a different 12AU7.

-PB

 

[revolverxz]

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. 

 

[Paul Birkeland]

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.