Long cables from turntable or phono stage

Nick, No. The vast majority of cartridges are inherently balanced output. So it is possible to use a true balanced connection from the cartridge to the phono input. It especially makes sense to do so if you have a truly balanced phono stage. Such products are still rather rare, but they do exist. Atma-sphere preamplifiers, MP1 and MP3, are examples of such. The connection from the cartridge requires three discrete wires (positive and negative "hot" wires derived from what are labeled "hot and ground" on the cartridge body, and a separate ground) into an XLR connector, rather than the two normally associated with RCA connection ("hot" and "ground", as per the color-coded labels on the cartridge body).

Thanks Doug, missed that in my fanaticism. In that case the capacitance of the cable is playing a big role in the loading of the cartridge. If it were me I would measure the capacitance of the cable, subtract the capacitive value of my one-meter cable, and then pick a capacitor of the resulting difference value. I would then plug it into the loading strip of the preamp, and see how it interacts with the cartridge. If a roll-off is detected, a lower capacitance cable should be found of a preamp could be placed by the 'table itself. But if the cartridge is not sounding rolled off then its good to go.

Nick sr phono cables can be balanced in the form of 5-din connector. If you separate ground for each channel you'll get fully balanced phono inputs.
Conventionally there are no balanced(to my knowledge) phono cables, but seen phonostages with balanced XLR and 5-din inputs.

The bottom line seems to be that without a balanced phono stage, you can't have a balanced connection even if cartridge output is inherently balanced.

Or could you use a Jensen transformer (Balanced line in to SE output)as was suggested to me in another thread?

Also I assume that by using a SUT, it would play the same role as the Jensen, while stepping up the voltage?

Any SUT is capable of receiving the signal in balanced domain, so you can run balanced from the cartridge if you have an SUT, regardless of the phono section. There are indeed balanced phono cables available too.

You know that funny ground wire on the single-ended (RCA) cables that no other single-ended source seems to need? That is there because you are taking a balanced system and running it single ended. A balanced system has a ground system that is independent of the signal, and has to be grounded separately. If the cable were balanced, it would be pin 1 of the XLR.