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Severe Static/Slight Hum SME 20/2 w/BAT

I using a SME 20/2, SME IV.Vi arm, Lyra helikon, hovland music groove XLR, BAT VKp10SE phono setup. (system posted here) I have a slight low level hum. I talked with Wally Malewicz yesterday. He thinks my xlr arm cable may be the culprit. I also have a bunch of static issues, which is where the discussion started with Wally.

Zerostat'ing barely reduces the static. Sometimes it literally glues the record to the platter with so much electricity.

Before I go buy a new arm cable, any idea's on troubleshooting the grounding? Or other idea's I should try?

Thanks very much! John
128x128jfrech

Showing 2 responses by twl

twl
3,251 posts
 
You need to ground your table. The main bearing housing is an appropriate point, or somewhere on a metal part of the subchassis that contacts the main bearing.

Static electricity can be generated by the stylus in the record groove. If it is not drained by a ground wire attached to the main bearing, then it will accumulate on the record, and sometimes even crawl up the stylus and make noise in the cartridge, in an attempt to get to ground through the tonearm cables.

If there is not a provision for a ground wire on the bearing housing or subchassis, then make one. You can test this by making a ground wire and stripping an end bare, and temporarily taping the bare end to the bearing housing or a non-painted surface of the subchassis. Then ground the other end of the ground wire. This should yield the desired results. If it does, then make the connection permanent in the best way you can.
twl
3,251 posts
 
Jfrech, since my last post mainly addressed the static problem, the hum may be approached by first checking for the possible sources of hum.

Is the hum present when the TT motor is not running? Or does it appear when you turn on the TT? This could indicate that the motor or some other part of the TT electronics might be generating the hum.

Also, another big hum source can be the positioning of the AC wires, in relationship to the sensitive phono cables. The AC power wires from any part of the system should always be routed well clear of the low level signal cables. The AC fields generated around the power cables can induce a hum on many low level signal wires. I recommend at least a foot of distance away, if possible. If you must have the AC power cables near or crossing over the low level signal wires, please do it at 90 degree angles, as this will be the best orientation to reduce any interference. Just this alone has reduced noise floor in many systems that I am aware of. This effect can also be caused by the low level signal wiring being in close proximity to the power supply sections of any of your components. Do a good check for this.

Those would be my first recommendations.
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