I have a rack mount amp setup that starts to make a horrible crackling noise after a short time playing through it. I'm pretty sure my F-1X preamp is causing it because I've switched out the speaker cabinet and several power amps to no avail. Anybody experienced the same issue? Does anybody have any suggestions?
Current configuration:
Furman PL-8 power conditioner
Alembic F-1X preamp
Peavey IPR 3000 DSP power amp
Epifani 210 AT speaker

Exercise the Volume control about 50 cycles, full sweep. One of mine does that crackl-y-static-y once in a while. Wouldn't hurt to hit all the pots. I don't tend to ever fool with them, but it's a good idea to give them a little twiddle every so often.

Might consider a different user handle too... Google knows everything already. Except how to fix an F-1X.

Hope that helps ya'!

I think they have contact points on the jacks inside that need to be cleaned (fine folded sandpaper) plus I use a 9mm pistol brass wire cleaning brush on the input/output jacks to clean them.

I agree that the back panel connectors could be the issue. The Effects Loop connectors have switches in them that can oxidize when not used. I use Caig DeoxIT D5 when I need to clean the back panel switch contacts on my Eden Navigator (where it is a common issue). Spray some into the connector and exercise with a 1/4" plug. Do this a couple of times and it should clean the switch contacts right up.

Note that DeoxIT is a contact cleaner and should not be used to clean other electronic components such as pots. 

DeOxit is just fine for cleaning pots. It does act as a solvent for the damping grease in some pots, so the feel of the pot will change, but the carbon track and the wiper will be just fine--better, in fact, because they'll be clean.

The effects send is generally the culprit. Check out this post
https://club.alembicguitars.net/index.php?topic=243.0
and let us know how it goes.

Hi Mica,
    I don't think the problem is the one described in the post. I've dealt with that before and exercising the jacks usually works. This is a loud horrible crackling sound and usually occurs after a short while under load. I'll go ahead and follow the instructions you sent, plus a couple of other ideas some members sent. I'll let you know.
                                  John

I suffered with a large crack sound through my two rigs earlier this year one was an F-1x and the other an F-2B rig and here is a thread that discussed the F-2B rig.
https://club.alembicguitars.net/index.php?topic=25841.msg265002#msg265002
I have taken the covers off cleaned contacts, tested leads, tried different wiring permutations, exercised the sockets and it was still making a cracking sound when I was playing any deep notes.
However having a couple of gigs coming up I pulled all the cables out and re-wired it and it worked fine without any noise so far.  I took the F-1x rig on a gig a couple of weekends ago and it sounded great. So not really sure I know what resolved it and i have even been able to increase the trimpot gains back up to their former levels.
I hope you find a solution.

Maybe a tube problem? It's worth swapping it out to find out.