Ground loop with Miyajima Premium mono

I hate to pop the bubble here, but there is no way that one ground in a cartridge is causing a hum on account of a ground loop!

You can prove this easily enough by tying the minus outputs of a stereo cartridge together- no hum will result!

If one channel is responsible for a hum, it is because there is something about that channel that makes it hum, like an open connection or something like that. I'm not denying that the hum exists, just the explanation for it is not a ground loop.

Mike, thanks for the detailed response.

This hum is bad news to me. I have a Kansui, which I like alot, and I was very close to buying the Premium BE Mono but now I think I won't. My Steelhead II doesn't sum through the fixed outputs and my VAC Phi Beta preamp doesn't have a mono switch. I don't want to have to do the summing-splitter IC thing and I certainly don't want to risk hum. Oh well. Seems like the manufacturer could fix this somehow.

Thanks, Ralph. I had the suspicion that this was the case, but actually forgot to mention it in my post. But, hum is hum and must be eliminated when possible.
It would not surprise me to learn that the hum issue has much more to do with the circuit design of the particular phono stage than with the cartridge itself.

I have tested a Torlai mono cartridge with single coil too.
Mr. Roberto Torlai is a Italian cartridge maker.
Same hum from speakers and the same answer that has given Mikelavigne on as to resolve the problem.Mr. Lukaschek,Benz Micro chief,says that the problem is greater with low output mono
cartridges.Dynavector and Lyra monos has double coils to avoid
loop (this is written on respective websites).
Matter more intriguing for me.

Sorry to change the subject somewhat....but I've been considering purchasing a mono cartridge and am concerned as to whether or not playing it on a stereo recording will cause groove damage. Besides playing mono recordings, I sometimes switch to mono on my preamp to play stereo recordings from the mid-sixties that have that ping-pong extreme left-right separation as well as stereo 45s to remove (to a certain degree) extraneous noise.