Clearaudio Concept ringing sound.. any advice?


Hi all, been having some nagging issues with a pre-owned Clearaudio Concept which I recently purchased.

My current setup is a Clearaudio Concept with a CA Virtuoso V2 cart hooked up to a Rogue Sphinx V2 and a pair of old but trusty Mission 753 non-freedoms (going to demo a Magnepan 1.6qr this weekend but that’s another story haha..)

Whenever the system is turned on, at mid to high volumes, there is an audible hum and a periodic high pitched ringing sound which comes and goes after a few seconds. Unfortunately, these sounds/noise is audible and jarring even, when I play my vinyls. However, when I place one hand on the top of the metallic tonearm base (above the magnet which holds the tonearm in place) and the other on the metallic volume knob on the Rogue, the noise significantly decreases by >50%. Hence, I think it might be a grounding issue but the grounding cable is properly attached.

I’ve also tried the following but to no avail:
1. Placed the TT a distance away from the amp
2. Made sure that both the TT and amp are running from the same power source (I don’t use a power conditioner, though that hasn’t been an issue with my previous setup)
3. Placed the TT on a separate platform at the amp
4. Made sure that the grounding cable is connected properly
5. Switched the Rogue with my old Pioneer A-400 but the same issue persists
6. Turned off all other electronics in the immediate vicinity 
7. Ensure minimal crossing of any cables/wires (though that has not been an issue in the past)

Any advice would be much appreciated, thanks in advance!

thesphinx
when I place one hand on the top of the metallic tonearm base (above the magnet which holds the tonearm in place) and the other on the metallic volume knob on the Rogue, the noise significantly decreases by >50%.


and

Switched the Rogue with my old Pioneer A-400 but the same issue persists


Phono stages can be finicky but when you have the same noise with two different amps that's a pretty good clue its the turntable. Unfortunately what looks good and works fine with line level isn't necessarily good enough for phono and the culprit can be elusive. Basically you are hoping to find Kizer Soze by eliminating the usual suspects.

1. Dirty connections. Thoroughly clean RCAs both male and female.
2. Ditto cartridge pins. 
3. Ditto ground spade and binding post.
4. Internal connections. Running out of things to check one time I decided to change RCAs and when I unsoldered one lead the other one came apart. Bad solder connection. Unlikely but it can happen.
5. Shielding. Keith Herron suggested this test- cut some strips of aluminum foil and wrap them around the phono leads. If you try this be sure to cover all the way to the very end of the cable.
6. RFI sources. Ultimately if the connections and shielding are good this shouldn't be a factor but if you flip the breakers off all the circuits and the noise goes away then at least you can flip them on one at a time and narrow it down.

Hopefully you don't make it far down the list. 

Good luck!


Do you have your wifi router anywhere near by? Alarm systems? Fluorescent lights?
Yes my router is on the shelf below. But turned them off and there is still no difference though..
 
Tried most of millercarbon’s suggestions too and I’m pretty sure it’s an internal connection issue. Probably have to spend some time this weekend to really try and troubleshoot this..
Recently purchased. Any chance of returning? With the checks you've done it seems pretty clear the problem is with the table itself.