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Scratchy, static-ey sound Dual 1019

jviss

jviss

Well-Known Member
I recently noticed what sounds like a static discharge sound with tonearm movement. If I move the tonearm to cue it, or move it up or down, I get a distinct noise that sounds like static discharge. I grounded the turntable to no avail. Could it be the tonearm wires?

Thanks,

jv
 
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Be certain that the headshell contacts and mating arm contacts are polished and cleaned. NEVER USE ABRASIVES FOR THIS!!!

If imported by United Audio, the Dual was factory-wired with a ground wire. Your system will hum if you choose to not use it.

So, if the turntable is as described, your hum situation can be improved by doing some creative re-wiring under-chassis.
At the mute switch's solder points, solder a thin wire from the chassis to one RCA socket shell, then to the other shell. Matter of fact, you can shorten and use the actual ground wire for this, as that ground wire will no longer be used to ground the chassis to the amp.
This works almost every time.
 
NoTransistors said:
Be certain that the headshell contacts and mating arm contacts are polished and cleaned. NEVER USE ABRASIVES FOR THIS!!!

If imported by United Audio, the Dual was factory-wired with a ground wire. Your system will hum if you choose to not use it.

So, if the turntable is as described, your hum situation can be improved by doing some creative re-wiring under-chassis.
At the mute switch's solder points, solder a thin wire from the chassis to one RCA socket shell, then to the other shell. Matter of fact, you can shorten and use the actual ground wire for this, as that ground wire will no longer be used to ground the chassis to the amp.
This works almost every time.
Click to expand...
Thanks. The contacts at the headshell are clean. There's no factory ground wire present, but I clipped a wire to a bracket on the frame. There's no hum; it's a scratchy sound that only occurs with movement of the tonearm, vertically or laterally.

Regarding your grounding modification suggestion, are you saying that the the chassis ground would now go through the interconnect shields to the preamp rather than through the separate ground wire?

Thanks,

jv
 
Yes, grounding through the shields is what I have suggested. It usually eliminates this problem. Seems that your arm is grounded through its balls, or has lost ground on one of the two cables within the arm.
 
NoTransistors said:
Yes, grounding through the shields is what I have suggested. It usually eliminates this problem. Seems that your arm is grounded through its balls, or has lost ground on one of the two cables within the arm.
Click to expand...

I've pulled it apart and found your suggested grounding scheme is what I have. It looks factory. At the muting switch wire terminal assembly there's a short between the interconnect (RCA) cable shields with a piece of solid wire that goes to a ring terminal onto one of the mounting screws. As I indicated previously, there's no separate ground wire.

I removed the tonearm wires (pulled a messenger in as I did). I don't have replacement wires, I think I may just swap them, end-for-end, and see what happens.

jv
 
What you have there is two silicon-jacketed shielded cables. Pretty good stuff, but newer single cables will possibly sound better, due to lower capacitance. Long ago, I rewired my 1219 and 701 with newer arm cabling. I uses a twisted bundle of five conductors. The fifth wire grounds the arm to the chassis, and can also be routed to the green [right ground] cartridge pin, which is usually factory connected to the cartridge's housing.
 
Did the noise only occur when you touched it to move it or does it occur when it operated automatically?
 
Pio1980 said:
Did the noise only occur when you touched it to move it or does it occur when it operated automatically?
Click to expand...

I don't remember! But, it was clear that it was due to movement; I think I even pushed the tonearm head with my fingernail and it still did it.

Good question, though. What are you thinking?
 
Sometimes a 5th black wire tied at the headshell area to the headshell or pipe screw, ect. The phono section is very sensitive and the hand proximity pick-up from the capacitive coupling of the pipe to the cart wires is likely if ungrounded/poorly/intermittently grounded.
 
Pio1980 said:
Sometimes a 5th black wire tied at the headshell area to the headshell or pipe screw, ect. The phono section is very sensitive and the hand proximity pick-up from the capacitive coupling of the pipe to the cart wires is likely if ungrounded/poorly/intermittently grounded.
Click to expand...
Are you referring specifically to the Dual 1019, or just turntable in general?

I know this TT works well, and is free of such static as designed; something must be wrong, or different with mine. Maybe it's really not grounded well, and since it's so dry out, I'm getting static discharges as I move the tonearm?
 
Well, statics a prob with low humidity in the house this time of year.Should be around 30% or so.
Unless you are shuffling across your carpet in wool socks to approach the tt, it would seem that since you moving the tonearm is when the noise occurs, that therein would lie the fault.
If you had a meter so you could check for continuity where it should be, and where it shouldnt be, through the full range of movement of the tonearm . An analog meter would be best for this I think. And I would remove the cartridge for this (safety 3rd).
In order to get this solved, I think you have to start compiling a list of definites, its that list that will reveal where the problem is.
 
jviss said:
Are you referring specifically to the Dual 1019, or just turntable in general?

I know this TT works well, and is free of such static as designed; something must be wrong, or different with mine. Maybe it's really not grounded well, and since it's so dry out, I'm getting static discharges as I move the tonearm?
Click to expand...

Most TTs in general. Not all separate arms have this sort of grounding for any number of reasons like non-conductive arms, ect. If it's not happening during play I'd ignore it and play it in autoload mode but that's me and I have a few good TTs to play with.
 
Update

After spending a couple of hours taking this apart and turning the tonearm wires end-for-end to no avail, I discovered it's the cartridge, or cartridge to holder connection. I haven't really fixed it yet, though.

I have one of these goofy Shure M80E-D19 cartridges, with the spring suspensions. When it bounces up and down I get the static sound.
 
Theres clean or loose, hopefully its not the leads themselves that are faulty. I think I would lose the cart though and get a normal one that cant move once mounted, that spring loaded business was probably ok when things were new, but now the tt has enough age on it to where the more stable things are the better it will like it.
 
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