The hummig is back! At least part of the time. Not to drag this out, I'll try to be quick. I bought a new amp, an Ampeg B100R and love it. If you recall my post of about two weeks ago, I had a humming in my Fender Bassman 60 amp, and it's coming from my Ampeg sometimes. I got the Ampeg a week ago, plugged it in, and it was dead silent, until I tried using my NE-1 EQ. As soon as I hooked it up - HUMMING! It then hummed every time I turned on the amp for the next two days, after that, it was gone. Now, Monday night and last night (Tuesday) no humming at all. Then after playing for about an hour last night, I turned down the gain and master volume all the way, plugged in my Zoom 506II effect, and, you guessed it - HUM! Could these effects be doing something to the pre-amp? If it is, could the hum go away after the amp discharges? BTW, how long does this take? The few times I turned the amp on and off last night resulted in nothing new; it was still humming. Also, a strange thing happens when it hums: My Yamaha bass is extremely quiet, but when the amp hums, the B,E and A string send a noticeably weaker signal to the preamp (this amp has an indicator light) but only from the neck pickup, the bridge pup is fine. I know this sounds insane, but, these things are really happening. Help if you can. Thanks, Mike J.