Question about NAD 7400 vs new integrated amp


I’m currently using the power amp in an NAD 7400 to drive my Polk SDA 2B speakers. The Polks are reasonably efficient (89.7 I believe) with 6 ohm nominal impedance, but are also known to really want plenty of current to sound their best. I have been wondering if I should continue using the 7400 to drive them, or perhaps look at something else. I’ve had my eye on a Musical Fidelity m5si integrated, and comparing the specs on the two is a little difficult for me since they are expressed differently.

The m5si is rated at 150 WPC at 8 ohm, 275WPC at 4 ohm, and is said (by the manufacturer) to be a high current amp. The NAD is spec’d at 100 WPC continuous at 8 ohm, with short term dynamic power of 370 WPC at 8 ohm and 440 WPC at 4 ohm.

Can anyone weigh in on whether or not you feel that the NAD 7400 is plenty to get the most out of these Polks, or would moving to something different like the m5si give better results?


Thank you,


The m5si has almost twice as much current by quoted specs.

Only your hearing will determine how much better SQ if any.

My $.02…get an integrated with HT bypass and a voltage trigger to activate it.  The preamp in the integrated will outperform the one in the AVR when used with stereo-only sources, and that will matter more than you imagine.  Look at Parasound Halo.


I think the M5 would be fine. I was just questioning the high current status, though like you said it is very close. If you had really difficult speakers to drive it might make a difference, but I think you are on the right track.