Opinions

It varies from system to system, of course. But more often than not the importance of a line-level analog interconnect can be expected to be greatest where the output impedance of the component providing the signal into the cable is highest, especially if there is a considerable difference between the output impedances of the two components. Sensitivity to cable differences will also tend to increase as cable length increases, and will often tend to be greater if the cables are unbalanced as opposed to balanced.

Regards,
-- Al

what do you consider a higher quality set of interconnects ?

Transparent Audio Super mm2 XLR on one end to Transparent  Audio Referance mm2 which is a couple product lines higher in the TA line.

I would first put a good power cord on the preamp and see what happens.

I have Transparent Premium cords on preamp, power amp, Bluesound Vault, DAC and Equi-1800 power Conditioner along with hospital grade 20A receptacles and a dedicated circuit.