So I was changing a lightbulb last night…

Grounding issue, as has been mentioned. I suggest you have two options.

1) You can hunt down why that light fixture isn't grounded properly. When you're touching it, your body is providing the ground. Luckily for you, you didn't get jolted.

2) Use something else for a TT light. I use one of these:

Works well and is unobtrusive. And of course, I leave it off when listening.

Good luck and ... Happy listening.

I loved buellrider97’s quote of “ Hold the TV antenna “.

I remember hearing that as a kid. I’d just touch the big metal tv channel selector know and the picture got better. My dad and older brothers would tell me to just stay right there! Don’t move!

Yes there is an effect/interaction with your body when you touch it. Also dimmer switches are notorious for causing hum, incandescent or LED. I’m having a very slight buzz with mine also. The LED track lights I first purchased weren’t dimmable so I went back those very small incandescent track lights which are controlled by a remote control dimmer switch. Works great and looks wonderful shunning down on the stereo system and speakers. I didn’t really notice the buzz until I was checking a different issue one night and turned the volume way up. I started checking for the buzz now and turned the lights up to look around. Of course as I turned the lights up the buzz changed and when the lights were on full the buzz was barely there. Turned the dimmer coming off and the buzz disappeared.

I have my entire stereo system on two separate 20 amp breakers which are independent from the lights. I also have a 20 amp balanced AC isolation transformer (Equi=Tech) which means the AC is 60-0-60 powering everything except my computer server. That is on one of the 20 amp lines going through a battery backup/regulated AC supply, then through a high end isolation transformer, then to the regulated 12V power supply with a very large bank of capacitors and up to the server. This also is USB isolated with an iFi galvanized power supply to my DAC.

So all this care and the buzz from the dimmer still comes through. Barely but it just shows the issue with dimmer switches. The only thing I can think of (if we want to keep some sort of AC dimming) is to research some sort of AC filtering that can be added right at the dimmer control. Ether a very small isolation transformer or EMI/RFI filtering system that would knock this out. It would have to be right in line with the switch so nothing from the switch or lights can feed back into the AC line.

@jonwolfpell you’re right, the buzzing was worse with the dimmer all the way down.  Maybe I’ll get a regular switch after all.

@musicfan2349 any advice on how to make sure the fixtures are grounded?

This has reminded me that I used to have a musician roommate in the room directly above this and he would always turn the lights off in the basement when he was recording music. I’m guessing he heard something similar with his recording gear as I’ve heard with my stereo gear. 

On another note, I pulled all of the LED’s to see if another bulb would make a difference but then realized I didn’t have any incandescents laying around but I did have a fluorescent so I plugged that into one of the sockets. For the first 5 seconds or so the light was like pulsating on and off and each time it came on the buzz would come from my speakers. Also the little light on the dimmer switch was going up and down with the light. It sounded like a light saber going back and forth. My dog was looking at me like surely this is Armageddon haha. I’m guessing the bulb just needed to warm up because it stopped flashing after a bit and stayed on. The buzzing wasn’t any better with the fluorescent vs LED. 

@harpo75 maybe for the sake of experimentation I’ll try some ferrite rings on the switch wiring and see if that does anything. 

dirte30 - That would probably help with RFI. Different sizes affect different frequencies. It can get pretty technical trying to examine the line noise for the frequency or frequencies that are causing the problem. But if you have some lying around it would be worth the experiment.