In short runs, I'd say there there is no sound quality loss. The job of balanced cables is to prevent electrical interference from effecting your signal. If the run is short enough and not running through any high electrical traffic areas than balanced cables don't provide any benefit except peace of mind.
Now that being said and knowing your a drummer, are you talking about this setup in a stage environment? If that's the case, the potential for interference from all of the other powered equipment, powerful speaker magnets etc.... could definitely justify the peace of mind coming from balanced cables. However, as JohnK pointed out, both the source and endpoints bust be actual balanced inputs & outputs to get the full shielding benefit of balanced cables. Converting to RCA half way would null such benefit.
Not my area of expertise though, I'm open to correction.
