After a l o n g break (due to my wife's illness) we are hoping to get back out there and gig... we have a BOSE L1 - 2 vocals, keyboard, and backing tracks going into the Tone Match...looking for an update to my ancient tiny iPod to play our WAV files... also, do I need some sort of DI box to get a better quality sound? And, my Roland FP-4 piano is sending a stereo signal into the mono Tone Match, making for a very thin, cheesy piano sound thru the PA... any thoughts/advice on these would be much appreciated...