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Hum with Ypsilon MC26L SUT that goes away with touching

I need help solving the hum problem.

Ikeda Kai cartridge -> Ypsilon MC26L SUT -> Ypsilon VPS 100 -> Cary SLP 05 -> Cary CAD 211FE monoblocks -> KEF Blade.
ICs between MC26L and VPS100 Stage 3 concepts RCA
ICs between VPS100 and  Cary SLP 05 Stage 3 concepts XLR
Cary SLP 05 and Cary monoblocks Shunyata RCA
Cary monoblocks to KEF Blade Shunyata speaker cables.

Connected ground from tonearm phonocable to SUT grounding post ->I hear 60 hz hum
Connected ground from tonearm phonocable to SUT grounding post + connected  SUT grounding post to VPS 100 ground ->I hear 60 hz hum (slightly decreased)
Connected ground from tonearm phonocable directly to VPS 100 ground (I read in the forums to try this) ->  I hear 60 hz hum
If I touch the body of SUT (metal) with one hand and touch the metal frame of the rack that sits directly on the floor, the hum disappears in all the above situations.

I used two shorting RCA plugs into input loading of SUT with tonearm cable connected to input-> No Hum 
I used two shorting RCA plugs into input of SUT without tonearm cable-> No Hum
I used two shorting RCA plugs into output loading of SUT -> No Hum

Any help in solving this hum problem is greatly appreciated.

Thanks
Kanchi
kanchi647
dover
2,243 posts
 
@kanchi647
Yes, but star quad will have much higher capacitance than a single twisted pair. Plus they use a ribbon wire - it would be interesting to measure the capacitance - I suspect it is not as low as you might think.

Otherwise it could be the shield - you could try connecting the shield at one end only to true ground - not the earth posts on the phono/SUT.

When you are touching the SUT you are grounding it.
kanchi647 OP
70 posts
 
@dover how do I connect one end to true ground? 
bukanona
174 posts
 
Capacitance is very important then used low ohm MC's. But it's very important only for a cable which goes from tonearm to SUT.


kanchi647 OP
70 posts
 
@bukanona the tonearm cable is a silver IC with WBT Nextgen Silver RCA from Reed 3p.
the stage 3 connect cable is connecting SUT to Phonostage VPS100.
bukanona
174 posts
 
You have stock cable from Reed tonearm? Try to use it and check the hum level if it's quite low now just crank the volume up and look for a changes. If  your silver IC  is supplied by Reed it should be OK. 
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