Crackling sound - where to start looking

[mvr_in_london]

Have an almost 4 yr old Crack w/ Speedball.

Works brilliantly with my HD800's - listening to it now and still can't believe how well these pair.

Have an intermittent problem that's cropped up recently.

Crackling/static evenly in both L & R even with the volume turned all the way down.  The crackling does not change with the volume.

Sound is not affected by source - the problem continues even if it's disconnected.

The first time I had the issue, I lifted it out of it's case to take a look and seeing nothing obvious, I put it back.  Crackling gone - absolutely quiet and worked perfectly.

Same thing happed again the next time.  So now, everytime I get that sound on startup, I move it around a bit and it clears.

It's probably a bad connection, but where & how to start looking?  I assume that the sound not being affected by the volume control should give some clue as to where the problem may lie?

Any help appreciated.

Mehul

[jimmy james]

I have the same problem, although I haven't installed the speedball upgrade yet. Only occurs on startup and the volume pot doesn't affect the crackling whatsoever. It can also get pretty loud for a few seconds and then it goes away, usually until I turn it on again the next time. I've had mine for about 6 months and this only started about 2 months ago. Sounds like our issues may be the same. At this point I assume it's a grounding issue somewhere in the chain, but some help/tests to check this would be really useful.

In the meantime I'm going to check the grounds and will let you know if I see anything...

Update:

So I just reseated both tubes a few times and noticed that the cracking on startup has diminished if not disappeared. However, I still notice intermittent crackling during playback, but with less intensity than before. Having gone through some other posts I am wondering if this is a tube issue and not wiring. However, I also notice that if I play with the headphone jack it seems to effect the crackling sound. Often I'll take it out and reinsert and then I'll get a loud crackling for a few seconds and then it seems to resolve. At this point I'm kind of baffled as to the genesis of this crackling is...

Anyone??

[fullheadofnothing]

Bad solder joint(s). Reheat them all.

[JamieMcC]

Always worth checking your tube pins a bit of a clean can work wonders if they are dirty. I found pins that are really black and dirty can stop a tube working completely.  Crackling, low volume, intermittent channel imbalance or one channel only can all be caused by dirty pins.