Advise on Long Phono Cable run

I think interconnect cable (or phono cable) within 1.2 m is standard, probably 1.5 max. Very short cables like 60cm can be used too, but sometimes it’s inconvenient. Probably 1m or 1.2m is optimal.

Unbalanced cable must be shorter than 4m max, i would say 3m max.

But balanced cables designed for use on long distance.
This is what professional are using in the studios, on stage etc.

Chakster made a good point. I recommended an MM cartridge, but as he notes, MM cartridges are capacitance sensitive. More so than either MI or MC types. So I agree with his recommendation for an high output MI type cartridge. Second, it goes without saying that you will have to have your cables specially made at that length. Several companies will do that. Among them I recommend AntiCables. In addition, going balanced would have no benefit unless you are running into a true balanced phono stage. A phono stage that just provides an XLR input but is single ended, will not get you all the benefits of a balanced connection. Balanced might be a bit quieter.

I am using vintage Grado XTZ (MI) right now, it’s an old discontinued signature model. Very nice!

But another Induced Magnet (IM) type i can highly recommend is ADC TRX II , here is some basic info from the manual. Look at this Sapphire cantilever with Vital III (PH type LineContact diamond). It was designed by Nakatsuka-San (now ZYX) for ADC in the 80’s. Replacement stylus assembly screwed into cartridge for superb rigidity. Hight compliance.

Long time ago i bought ADC Astrion, also with Sapphire cantilever, i must say the ADC TRX is completely different design from different person, so the performance of the TRX II is much better than older Astrion.

Maybe you can purchase an mc phono preamp with an XLR output (Avid does some good ones), place it close to the turntable and you can run a longer XLR balanced cable to a "standard" line input on your amp.
This would be the least noise prone approach.

The Gold Note PH-10 has balanced outpout, i have this phono stage, but i don’t use balanced out. Anyway, you can put such phono stage near the turntable with standard 1.2m RCA unbalanced cable, but from the output of the phono stage you will get balanced XLR for a long run to your amp. It can be 5m easily. Good idea, but the cost of the phono stage ...