I can only answer the question indirectly, I have a Concentra I with a phono card which replaced the original Pass Ono dedicated phono preamp. I thought the Ono was very good to excellent, just a little cool sounding, but extremely quiet and well detailed. I would say the Rowland card is very good. Not quite as quiet, but not to the point of it being a problem. If the phono card for the Concerto is much like the Concentra card, then you'd really have to be a nit-picker to need an out board phono preamp.