Moving magnet hum

Thanks for the replies. I went ahead and removed the ground tab from the green (right ground) pin, and it solved the problem. It seems this tab was causing a ground loop with the well grounded tonearm. No SUT was used for the LOMCs as the Aleph ONO has plenty of gain. I dont think I have seen a MC with a ground tab, and it has been so long since I used a MM, I was not sure this was the problem. I had rewired my Alphason tonearm with shielded Cardas 4X33 awg litz. The sheild is grounded within the someam base and I still have a ground leads from the base to the TT chasis and to the phono preamp ground connection.
The ungrounded portion of the leads within the tonearm are sheilded by the grounded metal arm, and the leads are effectively acting as balanced (+ & -) even though I am using an rca connection. I used only 1M of cable with a total of 6 pf capacitance.

keep all electric motors away including a bedini clarifier

Same exact problem.  First MM cartridge and cannot tolerate the intermittent buzz. How do I know if this cartridge has a ground tab? Sumiko Amethyst. Thank you.  Lou

Most cartridges don’t have a “ground tab”. The 4 pins are used as hot and ground, respectively, in each of two channels in a SE connection.  But in a balanced connection to a balanced phono stage, the ground pins deliver the negative phase of the audio signal. So your grounding problem probably lies elsewhere unless one of those pins you’re using for audio ground in an SE connection is loose or disconnected. Check that but also look at the external ground connection between phono stage and TT or tonearm.

You fixed the problem! Is the headshell metal?

Some installations may require the cartridge shield to be elec�trically isolated from the"RG" terminal. This can be achieved by removal of the ground tab.