vinyl1
Super Member
You should look in the database, not the thread.
https://docs.google.com/spreadsheets/d/1k_Wr5zx-hcJ0as6wub8wIqsMu2a67DyLhzE8grJp9mc/edit#gid=0
Your turntable is not listed, but most of the other Technics did not have hum.
Grado Hum Database
- Thread starter Sansui Louie
- Start date
You should look in the database, not the thread.
https://docs.google.com/spreadsheets/d/1k_Wr5zx-hcJ0as6wub8wIqsMu2a67DyLhzE8grJp9mc/edit#gid=0
Your turntable is not listed, but most of the other Technics did not have hum.
dusttones
Member
OK. I didn't see that doc - I was trying to use the link in the first post, which has been moved/deleted. Thanks for the list!
p.robustini
Active Member
I had no hum with my Grado Prestige Gold / 8MZ stylus on a TD-165. When I recently upgraded to a TD-160 I had hum instead. I learned from this forum about a ground rewiring that solved the problem.
I figure the TD-160's hum came from the fact it is missing the mains terminal cover box, a fact said to generate some hum. The TD-165 I used before had one.
I figure the TD-160's hum came from the fact it is missing the mains terminal cover box, a fact said to generate some hum. The TD-165 I used before had one.
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tuttebenne
Active Member
Have an Empire 498 and a Grado Prestige Silver cartridge. With the table unplugged I get hum when the tonearm is sitting in the rest but it is more pronounced as I move the cart to the spindle. At first I noticed the spindle bearing/suspension arms were magnetized. I degaussed it and the hum didn't change.
outlawmws
On the Run
Un-plugged how? Power? Audio? Ground? All three?
tuttebenne
Active Member
Power was unplugged. The ground and signal cables were still unplugged. Sorry for the partial symptom info.
outlawmws
On the Run
Ground loops can cause hum:
Do you have a separate ground wire for the audio?
Make sure the TT is plugged in
I'm assuming it's vintage and not a polarized plug; so try reversing the power plug, both on the TT and the amp. if the TT is plugged into the amp, you may need to try it twice as you reverse the amp's plug...
if all else fails, try taking the cart leads and winding them into a twisted pair.
Do you have a separate ground wire for the audio?
Make sure the TT is plugged in
I'm assuming it's vintage and not a polarized plug; so try reversing the power plug, both on the TT and the amp. if the TT is plugged into the amp, you may need to try it twice as you reverse the amp's plug...
if all else fails, try taking the cart leads and winding them into a twisted pair.
tuttebenne
Active Member
Outlaw,
Thanks for the quick reply. Let me respond to your points.
Do you have a separate ground wire for the audio?
I am using the ground wire that is in the signal cable (5 leads, one of which is ground). This wire is tied to the motor case and the turntable plinth (metal on an Empire). It is connected to my integrated amp.
Make sure the TT is plugged in
It has the same amount of hum regardless of plugged in or not, reversed plug or not (yes not polarized), and regardless of whether or not the motor is on.
I'm assuming it's vintage and not a polarized plug; so try reversing the power plug, both on the TT and the amp. if the TT is plugged into the amp, you may need to try it twice as you reverse the amp's plug...
I tried reversing the amp plug as well, but no difference.
if all else fails, try taking the cart leads and winding them into a twisted pair.
If you are saying I should tie the two signal grounds together, I will try that. If you are saying not to do that but to twist the leads around each other, I will try that.
What I don't understand is why the hum changes from very very low to very audible depending on where the tonearm is positioned. (in the rest its quietest, near the spindle its more apparent.
Thanks for the quick reply. Let me respond to your points.
Do you have a separate ground wire for the audio?
I am using the ground wire that is in the signal cable (5 leads, one of which is ground). This wire is tied to the motor case and the turntable plinth (metal on an Empire). It is connected to my integrated amp.
Make sure the TT is plugged in
It has the same amount of hum regardless of plugged in or not, reversed plug or not (yes not polarized), and regardless of whether or not the motor is on.
I'm assuming it's vintage and not a polarized plug; so try reversing the power plug, both on the TT and the amp. if the TT is plugged into the amp, you may need to try it twice as you reverse the amp's plug...
I tried reversing the amp plug as well, but no difference.
if all else fails, try taking the cart leads and winding them into a twisted pair.
If you are saying I should tie the two signal grounds together, I will try that. If you are saying not to do that but to twist the leads around each other, I will try that.
What I don't understand is why the hum changes from very very low to very audible depending on where the tonearm is positioned. (in the rest its quietest, near the spindle its more apparent.
hurdy_gurdyman
Active Member
Rek-O-Kut Rondine B-12 with plinth mounted Denon DA-50. Grado G-1+ with 8MZ stylus. With the table not grounded, very slight hum. With table grounded, no hum even with ear right up to the cone.
Dave
Dave
hurdy_gurdyman
Active Member
Does anyone know if a Rek-O-Kut B-12GH will produce hum? It's not listed in the data base. Someday I wish to replace my B-12 with the B-12GH, but not if I can't use Grado carts.
Dave
Dave