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Grounding Hum

I recently got a new TT for Christmas. It's an MMF 2.2 LE. I think there's a grounding problem or something because there is a slight buzzing noise present. I looked through past threads on the topic here, but nothing seems to fit this situation. I've checked, and rechecked the connection between the TT, and the preamp. I've even used a Fluke voltmeter to check for continuity between the two. I've checked the headshell leads to the cartridge. All is well. Maybe it's the ground wire connection to the turntable itself? I've run out of options. Any ideas?
licoricepizza
cerrot's avatar
cerrot
1,700 posts
 
I had a hum on my TT as well. Had to crank the volume up a bit, but it was there. Turns out it was my TT lite. I unplugged it from the Richard Grey 1200s (the lite) right under the phone stage to the shunyata hydra on the floor and hum is down 90%. Only apparent when I crank volumn up to 90 (out of 100). Will play a bit more but I may just live with it until I upgrade...something.
licoricepizza OP
48 posts
 
The situation gets weirder, and weirder....

As any good technician will do, I disconnected everything from preamp, still a buzz. I even unplugged the TT! After that resounding flop of an experiment, I swapped out the amp. Still a buzz. So I've eliminated the CD player, the TT, and the amp. All that's left is the preamp, the Monster Cables, and the VPI 16.5 (which is only drawing power when I'm cleaning an LP). The Stax headphone preamp is going to get taken out Sunday morning. Then the plugs get reversed. The other thing I thought of is that I have PC plugged in to different outlet, but they could be on the same circuit. I'm scratching my head over this one... Grounding is certainly an art, not a science,

Well, there's more than one way to skin a cat, and this cat will get skinned!
tjnindc
91 posts
 
I have been dealing with noise/a hum in the path of my turntable and phono preamp. It's a royal pain. The only other suggestion that I have heard that has not yet come up here is to find a cheater plug (on that reduces the three prongs to two) and try that on the amp and the turntable.

It appears that my noise is a result of outside interference (radio, tv, ???). I'm trying some different cables as well to see if I have any more luck reducing the noise.
licoricepizza OP
48 posts
 
I've tried every suggestion, but still no success. I've even tried "shielding" the preamp, the amp, and the TT with tinfoil. No luck. Any other suggestions? I'm scratching my head so much it may start to bleed.
ghstudio
141 posts
 
I had a hum coming thru my preamp from a little 12V transformer used to power something unrelated that was too close to the pre.....look around the unit for anything that might cause the problem. Also turn off any dimmer, automatic light sensor and flourescent fixtures anywhere in the house. (auto light sensors and dimmers can create havoc).
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