I've recently purchased a second hand ZP3 along with a ZMC1 to use with my first-ever turntable (Lenco L75) and first ever MC cartridge (DynaVector Karat 17D2 mk2).  My excitement was very short-lived as the hum was unbearable.

After messing around with cable runs, cable makes, isolation transformers, etc. I'm of the very strong (but inexperienced and uneducated) opinion that the input jacks being (on my ZP3) right next to the ZP3's transformer are a/the very likely culprit.  This even though I whipped up some shielded video cable use between the ZMC1 and ZP3 with only slight improvement (over my unshielded Decware RCA cables).  

One interesting note; when I disconnect the right channel between SUT and ZP3 the hum pretty much disappears; when disconnecting the left channel (after reconnecting the right) the hum reduces but is still there in one ear (checking with headphones).

Any advice as to troubleshooting would be GREATLY appreciated.  
best regards,
/Jody

I finally got around to checking a few things.  Looks like I might have a fault in the TT earthing line.  I get about 0.5-0.6 ohms on the cable but when I flex the earthing line I get something close to infinity.  I hope this is the only problem although I still have my doubts about the rear input jacks on the ZP3.

Any decent, quick and reasonably priced tonearm cable recommendations?  (to fit a Linn Asaka arm)