hum in system, ground loon? 60hz?

You don't have anything hooked up to it that touches a cable line do you. No video souce whatever. I found out that anytime I connect any video device, even a DVD player to a tubed preamp I got a ground loop hum. I tried the Mondial magic box and floating grounds on all different pieces. It improved but the only way to totally eliminate it was unplug the video device from the back of the preamp or switch to a solid state preamp. I know many of you will be dissapointed to learn that I finally chose the latter. If no video source touches your preamp, I don't know, but you could try floating the grounds.

Ok, Njonker and Jmc have good advice. Try lifting the ground (use a cheater plug) on the amp and then the preamp, but my guess is that wont do it, because I dont think you have a grounding problem. I have tube preamps that in combination with other equipment put out the same kind of hum. Now my stuff is not as expensive as yours and it surprises me that a Bat combo would, but it may be something else in or adjacent to the system. I have a vintage Luxman tuner that just plugged in, not even connected or turned on, will produce a hum through my system. (Anyone want to buy it?) In my second system I have an inexpensive Anthem preamp that in combination with my old Muse 100 amp puts put the same low level hum, and some people say it does the same with the Anthem amp, but its perfectly silent with any other amp I hook it up to. And the little Muse is quiet with any non-tube preamp. Not a good combination. You might also try plugging the preamp into a different circuit altogether if you can. Use an extension cord just to see if that eliminates the hum.

Then, how long have you owned it? If you bought new, have you talked to your dealer?

Thanks everyone for your advice. I did recently add video equipment. I'll start unplugging that first, then moving the cords around, I do have everything at 90 degree angles and about inch away from each other. If that doesn't do it, sounds like it's time to go from the amp backwards...THANKS!!!

Your problem is definitely not with the BAT equipment. It is most probably a ground loop. I had to put a cheater on one of my BAT amps and it solved it immediately. The BAT preamp and amp that you own are DEAD QUIET. All of your cables are excellent and should not be a problem.

Just in case you do not know what a cheater plug is, it is an adapter that has a female side that allows you to attach a three prong plug from your power cord, while the male side goes out with two prongs. It is also known as "floating the ground". They are somewhere around a buck to buy. Get a few of them as they are good to have around the house.

Let us know how well it works.

Jfrech: i think ya got it right in the title of your thread. it is a "ground loon" ( runnerup state bird of minnesota, after the mosquito). only thing to do is shoot it.