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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
three_easy_payments's avatar
three_easy_payments
2,097 posts
 
@kanchi647   

Are you suggesting to connect another wire between ground post from VPS 100 to Cary SLP 05? I do not see a grounding post on SLP 05. I'm saying ground your SUT to something. 

In my case I have a grounding post on my SUT and also one on my phono preamp.  It's unlistenable without this wire in place.
kanchi647 OP
70 posts
 
@lewm all my components are connected to Shunya V-ray which has 8 outlets.

Yes,  I am already grounding the tonearm to the SUT and the SUT to the phono stage. 

Is there a way to connect the ground from Phono stage to pre-amp and amps? Just touch the body of the amps? How do the wires stay in place?

@stringreen I used a junk wire and connected the SUT and made contact with the metal rack. Hum did not go away. It only goes away when I place my palm on the metal rack and have good contact. How do I make good contact using the wire to the metal frame? I will get some wire from lowes tomorrow.

@oldhvymec the contacts look clean. How do I clean the contacts? Is there a solution you recommend?

Thanks for all the help
oldhvymec
5,101 posts
 
Clean means shiny metal, to shiny metal. An eraser is good on copper or brass. A small wire brush (tooth brush size). I use carbon steel, brass bristle, and nylon. Wipe the surfaces, with isopropyl, contact cleaner, or a little WD 40 on a Q Tip. It will remove all the moisture and put a light protective coat. Screws with securements (nuts, wing nuts, the like) just work them back and forth...and a light lube, Wipe off the excess.

LOL never found a squeak I couldn’t stop...

If you’re worried about scratches. Tape off the work area with painters tape before you start, ay..

BTW, Nice Preamp.. Really one of my favorites..Lot of craftsmanship there.. That has an umbilical cord. right?
might want to unplug that and plug it in a few times.. clean the contacts... The UC.. Just to make sure..

You’ll get it..

Regards

willy-t
184 posts
 
I feel your pain and had the near same problem.Turn the power off at the breaker box then run a separate wire from the turntable ground  to the ground post in the wall socket 
then you should have a true uninterrupted ground
also you may want to make sure all your interconnect wires are properly attached to the end connectors.  I had an rca that the connection was broken on which caused a hum like you described
The ground directly to the outlet ground should work.  Good luck
Willy-T
rauliruegas
13,129 posts
 
Dear @kanchi647 : two things, first and to avoid ground loops we need to have a dedicated true ground connection ( this means a 2-3m. cooper solid tube underwround and touching a combination of salt and other ingredients and then atached to it a heavy cooper wire/cable. ) that will be connected directly to the phonolinepreamp and all electronicswill be be grounded to this item and your TT/SUT/TOnearm must has a ground wire to the phonolinepreamp. 

The second thing you need to do it’s to take out your cartridge and clean perfectly its output pin connectors and when you reconnected to the tonearm wires stay totally sure that the tonearm wire connectors makes a tigth connection into the cartridge output pin connectors.

Yes you have to clean any single input/output connector in your system and that at each connection it makes tigth connection.

Now your Kai cartridge has a low output level of 0.19mv along very low internal resistance of 2.5 ohms.
For me that cartridge will be better served with an active high gain phonolinepreamps than a SUT but this is only additional of what I writed here and obviously does not helps to your today issue.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.


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