This is probably noise from your amp. Have you replaced the tubes lately?
If you have to put your ear up to the tweeters to hear it, this is normal. If it is loud enough to hear from the listening position, you have something else goin on. May be RFI pickup from a ground-loop. Try ungrounding one component power cord at a time using a cheater plug. Always leave at least one component grounded.
If you put filtering anywhere in the system, you will lose some of the music.
If you have to put your ear up to the tweeters to hear it, this is normal. If it is loud enough to hear from the listening position, you have something else goin on. May be RFI pickup from a ground-loop. Try ungrounding one component power cord at a time using a cheater plug. Always leave at least one component grounded.
If you put filtering anywhere in the system, you will lose some of the music.