Crackling and static in the right channel [resolved]

[Cowwe]

I am going to give the chopstick test another try once I get home from work. For the meantime, could the fact that my issue is only on the right channel highlight some possibilities as to where the problem could lie? The left channel is completely fine.

[Paul Birkeland]

You can also rock the tube with those headphones in and look for two components moving differently that would otherwise be soldered together.

[Cowwe]

I have an update (I'm afraid it might be a pretty bad one).
I once again closely inspected my kit looking for any loose wires and poorly soldered joints, but couldn't find anything that caught my eye so I decided to move on to the chopstick test.
I had just my 12au7 in its socket while the 6080 wasn't inserted, and the power switch was off. I plugged the amp in, intending to then insert the 6080 and turn the crack on, but before I could I got shocked through (I'm positive but not 100% sure) the chassis.

[Paul Birkeland]

The chassis is earthed, so it's unlikely that you'd be shocked by the chassis, but it is possible that you were touching part of the IEC power entry module when you plugged the power cord in.  I would plug the cord into the Crack first, then the wall.

[Cowwe]

Today I went through testing everything once again.
Resistances measured correctly. The amp turned on correctly and the voltage check is within the limits:

1) 84   2) 170   3) 0   4)170  5)80
6) 0   7)104   8)0    9)106   10)0

I went on to plug a pair of old headphones. The crackling was still there so I tried tapping on each solder joint with a chopstick. Nothing made any notable difference in the noise.
The one thing that made the difference was rocking the 6080 tube until the noise went away.
Tonight I'm going to try to listen with different tubes and see whether it really was just the tube pins not making contact all along.

[Deluk]

Fit. Check for noise. Clean pins. Check for noise. Do this for all of your 6080's. Lots of wiggling can sometimes distort individual pin sockets. If so. contact can be improved if you give them a very gentle squeeze.

[Cowwe]

Yeah, it's definitely the pins not making good contact or some parts being dirty. Depending on how I insert the tube (depth or slight angle differences) my Crack either works perfectly, makes some background noise or won't start at all.
I've had the amp turn itself off a couple times while listening, and slightly moving the power tube turns it on again.
How would you suggest to clean the pins and socket? Is using alcool okay?

[ssssly]

Deoxit is the best thing I have found for cleaning contacts.

If that doesn't do I use a cutting torch tip cleaner. Which is basically a tiny hole file.

I would also check your volume pot connections again. I had a similar problem years back when I first built mine that ended up being a bad joint on the volume pot. Messing around with the tube was flexing the top plate enough to flex the wire braid to the pot and make/break contact.

[Cowwe]

My kit is officially making me go insane.
It had worked flawlessly for 2 days, then as I was listening it turned itself off. Now it's back to the same issue, where for some reason the amp turns itself off and if I wiggle the tube ever so slightly it turns itself on again (until it happens again).
I thought maybe vibrations from me moving at my desk might be moving the tube and breaking some contact, but it has happened even while I wasn't touching anything.
I went and reflowed a solder joint at terminal 13 since the red wire didn't look well covered, closely inspected every joint once mroe and tested the voltage as usual: everything is within standard values.
Setting the Crack to stand vertically, I went with the chopstick test again and tapped on all joints, cautiously moved the octagonal socket pins left and right and lightly pulled/pushed on wires: no changes at all in the sound and the amp kept sounding perfect for a good 10-15 minutes.
I put the kit back to its place and within 5 minutes of listening it turned itself off once again.
I have wiped the inside of the socket a bit and it looks clean enough to me. The pins themselves also feel pretty tight, and I'm not sure how I would go about messing with them to make a better contact.
Once more, please let me know if you have any ideas what else I can try. If you would like, I'm willing to send a close up picture of every single joint you'd like to see.
This amp is such a joy when it works, but this situation is so very frustrating.

[Deluk]

Socket looks clean. As it is new it should be. You could try and bend the contacts in a fraction with a tiny screwdriver. Cleaning the pins by pushing the through a sheet of Scotchbrite soaked in DeOxit worth doing. Wiser heads might be able to say why the unit actually switches off and which pin might be the cause. If it is safe to do so, have a poke around with the chop stick when it is this "off" state.

[Paul Joppa]

You used the phrases "turned itself off" and "turned itself on" - does this happen instantly, or does it fade in and out? Is there a loud click, or a thump, or does it just go silent? Have you measured voltages while it is silent (yes that's hard to do!)?

It iis likely to be a thermal expansion that causes a disconnect. These details might help locate the intermittent connection.

It may be a broken wire, where it was nicked when the insulation was removed and the insulation crept back to cver the which then broke in subsequent handling. A little gentle yanking of wires can reveal this kind of problem.

[Cowwe]

When I say it "turns itself off/on" I mean it happens as if I would be removing the plug or flipping the power switch. The tubes start glowing fainter until they go dark, while the volume gets lower until it's silent (in the span of about 5 or 10 seconds). There are no clicks or noises, aside from two quiet thumps at the very end (one per ear), which I'm positive the amp does normally whenever you would turn it off.
From what I have noticed it's not fading in and out, but rather it fades out and stays like that until I mess with it. I haven't tried leaving it alone after it fades out to see if it fades back in, though.
My amp has been unplugged for a couple hours now so it's completely cool, but it isn't turning on if I plug it in (I would need to go and move the tube).
I'm going to try and measure the voltages right now as long as it's in this state.
Thank you again for your patience in assisting me, Paul.

[Cowwe]

Here are the measurements while the amp is plugged in, but the tubes and LED's are not lighting up.
terminal 1  - 242V
terminal 2  - 248V
terminal 3  - 0V
terminal 4  - 248V
terminal 5  - 242V
terminal 6  - 0V
terminal 7  - 0V
terminal 8  - 0V
terminal 9  - 0V
terminal 10 - 0V

[Paul Birkeland]

Those conditions would be neither tube conducting.  Can you see the orange glow from either tube under these conditions?  This hypothesis doesn't fit the "instant off" condition you describe though. 

This is very much not an issue with tube socket pin fitment, as both the 12AU7 and 6080 are unable to operate under these conditions. 

[Cowwe]

No, in these conditions neither of the tubes, nor LED's, glows.