i am trying to decide between a NAD C440 and a parasound TDQ1600 and an AMC tuner. which is the better of the 3 tuners? also, trying to decide between the pre amps- AMC, NAD or parasound. i am not familiar with either product, so ANY advise would be greatly apprieciated. i already have the power amp, it is a NAD C270. THANKS!!!