Very powerful clean sound. Much better base response than the Onkyo receiver it replaced. All tone adjustments are able to be done with the remote which was a big plus for me.

I am powering 400 w cerwin vegas with the NAD C399. I have a JVC cd player connected and a Bluos node 2 also connected. Plenty of power and crystal clear at any volume and I do push it to its limits.

Crutchfield is the best way to buy. Great selection and amazing support! I haven't plugged in the c399 yet, it replaces a c372 that I've been thrilled with for a decade, so I think I know what to expect! But my purchase satisfaction will have me coming back to Crutchfield for sure!

Incredible sound quality. The improvement over my previous 50-watt-per-channel Onkyo when playing on the same speakers is like night and day. Highly recommended

Excellent -- I bought the NAD C399 as well as the BluOS MDC2 system as well (the combined were sold out). I strongly recommend the added connectivity from the BluOS MDC2. Great sound and dynamic response. One small complaint, I would love to see the BluOS app or a NAD app be able to turn the system on/off rather than using a separate remote.

Very happy with my purchase. Really have made my speakers come alive.

I'm returning it. It was not clear when buying this C 399 that speakers A and B cannot be selected separately (unlike every other amplifier I have ever owned over 50 years). Since one of my rooms have 4 ohm speakers and one room have 8 ohm speakers, they should not be played simultaneously as this amplifier forces me to do which may eventually ruin the amplifier. Why the manual doesn't explicitly says that speakers A and B cannot be selected separately was unfortunate. Even the remote has buttons for speakers A and B, but the manual does note that those buttons don't work for this model C 399!

Great sounding stereo. Plenty of power.