Hum from Grado on LP12.. Better carts to consider?


I've had a problem with hum on my LP12 for as long as I can remember. The table (bought used) came with a Grado Signature 8MZ and I've since tried a Grado Z+ that I had from another table. Both have the same amount of hum. I have a lot of RF and noisy AC in my house. The hum is noticeable when I switch to phono and gets louder as I move the cart over the rim of the platter. From there it decreases as I move the arm towards the spindle. (The table is 80's vintage with Ittok and Circus/Lingo upgrades).

A (non-Linn) dealer said 'oh Grados do that on LP12s - lack of shielding'. My Linn dealer didn't nave a strong opinion. He suggested a Benz Ace H given my under- $700 budget. From reading the Agon forums, some think an AT150 M series has better sound for less $. I've also heard good things about the Dynavector DV-20X. Does MM/MI vs. HOMC matter in terms of hum or is the degree of 'shielding' a variable from cartridge to cartridge no matter which type? Does a good review on a MC necessarily extend to the HO version, as opposed to the LO/MO versions?

My system: ARC PH1 (48 dB gain, variable loading via soldering iron)
ARC LS2BII
PSE Studio IV/V's
Audio Physic Tempo III's
FWIW: Meridian 508 CD player is dead quiet in this system.

Music: from Joni Mitchell to Ian Dury and the Blockheads, Monk to Mozart.

Thanks for any knowledge you can impart!
geor
Yes. I would second the suggestion of a Lyra cartridge for your LP12. The reason they are such a good match for the Linn table is that Lyra used to manufacture all of Linns higher end MC phono carts, including the Troika, if I'm not mistaken. I'm not sure if they still do.
Thanks All. The Lyra sounds like a good fit, but the Dorian costs about $1100. It must have to do with exchange rates, because I remember it was around $750 a few years ago. Maybe there is presently better value in the Japanese AT for the same reason. (US Dollar) I have German speakers and had a Scottish tonearm that I bought (new) at bargain prices 5-10 years ago when the US dollar was stronger.

Also my phono pre needs higher output. I'm still wondering in general about MM vs MC and especially low or medium output cartridges. Are the advantages worth looking at a MC phono stage. There is a current thread on MM vs MC with 1000 posts but I haven't gotten much out of it yet.
Thanks again!
a phono step up transformer is another option if you chose a low output design.
I have a Grado "The Statement" on an old Linn LP12 which I bought new in 73 or 74 can't remember. I now have an Itok arm which was not original. I have absolutely no hum. My dealer was a Linn dealer for many years and sold Grados with Linn tables. Do you have cable connected to a device in your system? It is easy to create a ground loop which will cause hum.
I have a Grado Signature 8MR on a Sondek using a Linn Basik LVX arm from 1984 - this unit is in storage back in Australia. This has no hum at all into a very high gain preamp (the preamp could handle a moving coil cartridge without a transformer).

Something must be wrong.

Regards,