Marsh A400S Balance or RCA?

Pretty much here is how it goes. If you have 'true-balanced'--starting from the cd player--to the dac---and to the preamp--- then balanced to the amp will be significant. However there some pieces that have balanced as a pass through. Meaning the circuits aren't 'true-balance' in design. ---Don't know about this Marsh. The long ic thing,as stated above, is a good reason to use bal.

It could be in some cases the match could be better. I doubt much difference will be there most of the time. Too many very high quality companies like Conrad Johnson that don't even give you the option for it to be that major. If you have very long runs to the amps though it would be a better idea. I use the RCA's on mine and certainly don't think much is missing if anything, my run is only .75 meters.