+1 for carlsbad
My single-ended preamp easily drives my 25' RCA interconnects to my mono blocks. Of course, they are quality cables & connectors.
From what I can gather, if the preamp (single ended) has a low output impedance it would/should be able to drive long runs of interconnecting cable. This simple fact will explain why some preamps are unable to do long IC runs. This does little to excite me to look for a balanced topology preamp to replace my current gem.
Sounds like bias harping to me. Good circuit execution etc. is not limited to balanced component design.