Hey Uncle,
Cables. Most likely a funkly cable or the guitar jack itself is whacked. I get it all the time. A jiggle on the cable and, poof, it's gone. Unless you know for a fact the cables are new or righteous, thats what I'd be looking at.
I run my electrics (btw they are a Ricky 360/12
FireGlo and Fender Strat) through a Line6 Pod ( amp modeler ) and into a Behringer EU1202. Nearly every crackle I get is caused by cabling or loose jack. The Line6, though, has a noise gate which alleviates a lot of extraneous static/crackly symptoms. Also, if you have a Rickster with the extra jack, Rick-O-Sound, be sure you are plugged into the Standard jack and not the Rick-O-Sound. Never use the Rick-O-Sound unless you have the right gear. ( see
www.rickenbacker.com )
If you'd like detail on how I have my Behringer/Line6 kit set up to the computer, just let me know.
Les