How to reduce hum with phono preamp

[vmscbe1974]

Hi
its not a feedback precisely it is the sound i get in speakers when the platter is spinning if i tap the turntable body or the table on which my turntable is placed.
Regards
Srinivasan.M

 

[omishra]

Ok so its missing damping in TT and isolation in TT feet. Now you will receive solution for above two problems separately.
Now experienced member can direct us correctly.

From my side it seems using heavy damped rubber mat could solve it in simple way. Additionally putting layer for doormat + stone + doormat below TT could be other part solution.

 

[jls001]

Hi
its not a feedback precisely it is the sound i get in speakers when the platter is spinning if i tap the turntable body or the table on which my turntable is placed.
Regards
Srinivasan.M

Please do not tap in future:yahoo:

On a more serious note, that's a very common "feature" with turntable playback in general. That's why it is not advisable to put a player on wooden floors as walking near where it is placed causes vibration on the support. This induces unwanted vibration in the cartridge. So a firm floor, or at least wall mounted shelf is recommended for placing your player.

 

[vmscbe1974]

What is TT damping and how is it done? Now a days rubber bushes are not available . any solution to it?
Regards
Srinivasan

 

[basashanker1965]

The real problem is one of the wires from the cartridge to the amp is broken inside.If you use a multimeter continuity tester .remove the headshell,check continuity from the 4 pins to the rca connectors.one of the groung pins will be broken inside.