Cable from SUT to Phono Preamp

Any pair of RCA cables will do so long as they are short in length - half a meter (19 inches) or less! This is to avoid high frequency roll-off! Here the shorter the better applies! I have a pair of the Sony ST-10 mini SUTs that plug directly into the rca jacks of the phono stage - no cable needed! 

Even better would be a pair of ICs 1/4 meter in length - 10 inches.

The signal is low enough in level that the noise level or noise injection susceptibility of the second cable is as critical as it is when going into the SUT from the cartridge and turntable itself.

Any cable will physically work, but it should be as good at shielding noise as the cartridge to SUT cable is.

The interface from the SUT to the phono stage is a low level high impedance node the the goal here is to use a short, shielded, low capacitance cable.  The need for shielding is a noise pickup thing and is at odds with the low capacitance goal.  Keeping the length as short as possible helps combat the extra capacitance added by the shielding.