2. amps-preamps
  3. 188797-188853

Question about NAD 7400 vs new integrated amp

Hello,

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,
Greg

rhythm5
rhythm5 OP
11 posts
 

rick_n,

Yes I am only using the power section of the NAD.  I currently have my sources connected to an AVR, and the main front L/R pre-amp outputs of the AVR going to the NAD's power amp in jacks.  So these days the whole preamp section of the NAD 7400 is not in use.

My plan is to get a dedicated stereo preamp or integrated amp with an HT bypass input for my 2 channel music listening, and only use the AVR for multi-channel listening (movies).  Whether I buy a new preamp or integrated amp depends on whether or not I'll continue driving the Polks with the 7400's power amp.

Greg

rhythm5 OP
11 posts
 

zlone,

I have been looking for a doubling of wattage also, but thought that perhaps the 150/270 spec on the M5si might be enough.  The specs on this amp also mention "512W peaks into 2 ohms", although I'm not exactly sure what that means regarding stability.

A complete doubling of power from 8 ohm to 4 ohm is a bit harder to find in integrated amps, as opposed to a separate power amp, but I was hoping to find an integrated that would do the job (hopefully at max $2500) just due to limited shelf space (and budget).

If I run across an integrated amp that is rated at 100/200, would that be a better bet than the 150/275 of the M5si?  Or perhaps that all depends on the design of the particular amp.

Greg

fuzztone's avatar
fuzztone
5,598 posts
 

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

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

crustycoot
644 posts
 

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.

HINT 6

zlone
657 posts
 

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. 

More to discover