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.
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.