Advice needed jelco sa750d fitted earth hum

[vandergraafuk]

Hi Chaps,

I have finally completed my sl1210 with Mike New bearing and bonded base plate plus bearing, copper armboard and Paul Hynes SR7EHD-21/27 power supply. I removed the stock tone arm and when removing it I noticed an earth wire grounded on the pitch potentiometer. The new arm was fitted and I have been setting up the arm when I noticed a bit of a hum when the volume was turned up. Is this down to not adding a wire from the arm board to the pitch potentiometer??? The Jelco RCA lead has an earth wire which is connected to my SUT. Any ideas folks? I thought I would ask before I start experimenting earthing the arm board. Just a thought would it be worth earthing to the SR7EHD-21/27 power supply??

TIA :eyebrows:

[chris@panteg]

Try attaching the pitch earth tag to your mike new armboard .

When I swapped out the arm on mine to an SME 309 , I did this and have never had any hum at all !

[Frankyc2003]

+1

By reconnecting the armboard to the mains ground (the pitch fader PCB for instance), you will remove any hum!

You can make your own cable terminated with small spades and fit the end of it tight between your armboard and one of the mounting metal washers for example.

;)

[Canetoad]

+1 Did that with mine and have no hum problems. :)

[vandergraafuk]

Found it adding cable from copper armboard to pitch control did not cure it. Was down to the cartridge itself, left channel. Hum disappeared when I detached the headshell. New dl103R fitted hum gone. Thanks to everyone's response. :) one happy bunny, spinning the vinyl with big grin on my mush.

[chris@panteg]

Found it adding cable from copper armboard to pitch control did not cure it. Was down to the cartridge itself, left channel. Hum disappeared when I detached the headshell. New dl103R fitted hum gone. Thanks to everyone's response. :) one happy bunny, spinning the vinyl with big grin on my mush.


Great , Glen I see you have your LP12 all boxed up , prefer the Techy then ?


Or is the Linn just resting ?

[vandergraafuk]

Yes the lp12 is resting. I am having fun with the techies robustness. Not dainty like the lp12, just look at it the wrong way and it goes off tune. Now all I want to put in is the Mike New platter, please someone give me reasons not to buy one :stalks:

Or will I have to say Frank made me do it?

[RobbieGong]

Yes the lp12 is resting. I am having fun with the techies robustness. Not dainty like the lp12, just look at it the wrong way and it goes off tune. Now all I want to put in is the Mike New platter, please someone give me reasons not to buy one :stalks:

Or will I have to say Frank made me do it?

Lol ! Wish i could but I can't - Mikes ETP Platter was the icing on the cake for me and is superb !