2. analog
  3. 1232660666

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
licoricepizza OP
48 posts
 
Here's some additional information, which may help:

If I flip the switch on my preamp (NAD1155) from MC to MM, the hum reduced, but doesn't go away. However, it seems that I, then, act as ground, because there is a more pronounced hum whenever I touch the preamp. The hum comes from both channels. A bypass wire from the turntable to the preamp had no effect. Moving the turntable (to the extent that I could) had 0 effect. The amp (B&K ST-140) is connected to a Stax SR34 headphone preamp. Then Monster Cables from the Stax unit to Vandersteen speakers.

Thanks to all those who contribute to my problem resolution.

Lee
80stech
20 posts
 
Try flipping the AC plug-ins around in their sockets one at a time. If your on split phase with ground return this could help. Let me know if this helps and I will explain why it does.
mosin
410 posts
 
Weird, but worth a shot is to try grounding your preamp to a piece of digital equipment, like your CD player or DAC. If that doesn't work, try the same, but with the ground from the turntable to the digital piece.
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!
More to discover