Moving magnet hum

Oldears

Have you tried disconnecting your turntable ground wire? I had several MM's that I got hums with the ground wire connected but nothing when I disconnected the ground.

No grantees but whorth a try. Some of these cartridges are very tricky.

Good luck.

AEW

Were you using a SUT with your MC cartridges going into the MM input on your phono stage? Likely you have a bad ground between your TT and your preamp, which is now loaded at 47k...not the much lower load seen by your SUT, which also acts to isolate your TT. This is a common problem when moving from low impedance to high impedance cartridges...your system is now revealing all your grounding issues.

Make sure your tone arm is grounded, and you have a ground wire running from the TT to your phono stage. If turning the TT motor on and off makes a diff, try lifting the ground on the motor or your phono preamp.

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