Pearl 2 doesn't get along with Jelco SA370 Arm

[McQuaide]

Hi all,



My Pearl 2 has been running for 7 years now and remains a consistent favorite with my local audio buddies. I recently upgraded to a Micro-Seiki DDX-1000 turntable which accepts three tonearms. The best arm I have on the table is a VPI JMW9 signature which is completely quiet. Every other table I've used with the Pearl 2 has been quiet as well.



The Jelco, on the other hand, has an annoying ground buzz. It's a bit different from other arms in that it has two ground wires, one from the base and one from the arm tube. It has a 5-pin DIN connector in the base.



I've tried three different interconnect cables, shielded and unshielded, and have been pulling my hair out with this noise. Any suggestions for things to try? I was thinking of getting an arm wire to RCA converter box like the one on the VPI if I can locate one.


Thanks in advance.

 

[vdi_nenna]

Nice rig.

Just for testing purposes, to see if the buzz goes away when using the Jelco arm, have you tried the following?

Have you tried disconnecting the VPI arm completely to see if the buzz goes away when using the Jelco?

Is the base metal all the way to the arm? Have you tried lifting the base ground wire?
I'm thinking there's a loop between the base and the Jelco. Although a buzz (120Hz)and hum (60Hz) are a little different. Are there any power lines or transformers closer to the Jelco?

Is one arm using a mono cartridge? Which carts?

 

[scott wurcer]

I've tried three different interconnect cables, shielded and unshielded, and have been pulling my hair out with this noise. Any suggestions for things to try? I was thinking of getting an arm wire to RCA converter box like the one on the VPI if I can locate one.


Thanks in advance.

I ended up running differential all the way, the 5pin DIN makes that easy as long as the cart does not have a ground shorting clip. More recently I used two 3.5mm to RCA cables and 3.5mm stereo jacks mounted at the TT. You can then switch from SE to differential simply with two mono 3.5mm to RCA adapters. How you ground the arm and table then becomes a free parameter.

 

[McQuaide]

OK well I'm a confirmed dummy, it was the flatscreen TV that sits next to the table. It doesn't bother the VPI but creates a huge noise with the Jelco. TV is off and the arm is silent. Thanks for the suggestions anyway.


BTW the cable I'm using is DIY, it's Mogami 2534 which has two pairs and a shield. I grounded the shield. It's low capacitance cable which is good, since the MM cartridge I'm using (Signet TK7LCa) is very sensitive to that. The other cable I was using had almost 300pf in it which made the cartridge shrill and almost bass-free. With 60pf in the cable and 100pf in the Pearl it seems to be a little bass-heavy now so will look to increase to ~250.

 

[vdi_nenna]

 

[McQuaide]

Nice rig.

Just for testing purposes, to see if the buzz goes away when using the Jelco arm, have you tried the following?

Have you tried disconnecting the VPI arm completely to see if the buzz goes away when using the Jelco?

Is the base metal all the way to the arm? Have you tried lifting the base ground wire?
I'm thinking there's a loop between the base and the Jelco. Although a buzz (120Hz)and hum (60Hz) are a little different. Are there any power lines or transformers closer to the Jelco?

Is one arm using a mono cartridge? Which carts?

I didn't respond to this, first, thanks!


The other cart is an AT33PTG. I find it more "polite" than the Signet and less exciting.