I was using my AC30 with my Marshall 4X12 cab at low volume and I noticed a tiny bit of crackle in the sound. Put the amp away wondering if something major is going on, not really wanting to think about it. I got my Germino Classic 45 today and hooked it up to the 4X12. Same problem as well as some fuzziness on the very lowest notes F, F#,G. The good news is that the issue isn't with my AC30. I thought it might be the speaker wire as I had soldered it up myself but I changes wires and same thing. Then I plugged the Germino into a different speaker with it's own wire and no problem at all. So any idea as to what the problem could be or how to track it down? Is there a way to check wiring/connections with a voltmeter?