I have the same problem. My Creek amp hums when I turn a halogen lamp on that is on the same circuit. Loudly when lamp is on "high" setting, less so when on the lower setting. From my understanding, toroidal (sp?) transformers are quite sensitive to this type of thing (it is common and shouldn't damage your amp). Freaked me out when it first occurred because I had bought the amp used from a dealer 3,000 miles away. I eventually figured it out.
So now I listen to music with just a flashlight on...:>)
Regards,
So now I listen to music with just a flashlight on...:>)
Regards,