NAD Amplifier Design

zingo

I'm doing a deep dive into NAD's amplifier design and how they rate the output power. They rate their average output at the same power for both 4 and 8 ohm impedance loads, but dynamic power progressively increases at the load impedance drops as expected. I understand the marketing benefit of offering a constant power output and low distortion with headroom regardless of speaker impedance, but is there more to the amplifier design, or is this just "NAD's thing"? I read that there is also voltage switching as need to produce more power for a high draw, but I assume it's just a well designed class A/B circuit?

NAD Full Disclosure Power

Tony M

I don't understand their design BUT I know it works VERY WELL on my SDA-SRS2's that are 4 ohm speakers.

I have a NAD C370 integrated.
Pic. of the guts from the Web;

halo

I have my hands on my first piece of NAD gear in the form of the C 316BEE integrated amplifier. It sounds ridiculously good and it's not even remotely short on supplying the power to drive the speakers. The only thing I dislike about it is the volume level control knob (goes from too quiet to too loud too suddenly).

I'd like to see an upgraded version of this with better caps and resistors and an IEC on the back so one can swap out power cords.

In its OE configuration, it can take the heat and bring home the bacon with money leftover for other upgrades

jayu969

Have always liked NAD...all the way back to my college days.

GlennDog

jayu969 wrote: »

Have always liked NAD . . .

Me, too! Great CS, too (at least it used to be. Hope they are still top notch as I'm flirting with a T 777 V3)

I had a NAD CDP about 18 months out of warranty and they fixed it No Charge!!
Loves me some great CS!

zingo

I was trying new crossovers on a pair of DIY speakers and accidentally wired it as a 2ohm nominal load. They were connected to my NAD integrated and I listened to music for about an hour before feeling the top and it was hot!

I don’t think an NAD integrated is designed for a constant 2 ohm load, but it ran great!

Tony M

That's a tough load for ANY amplifier I would think.

My NAD C370 powers my SRS2's easily. They're the 4 ohm version. I'm glad I never sold it separately from it's matching tuner. I had the 2 advertised and a few emailed me wanting just the 370. I held tight and the people passed.
Here's why it powers the 4ohm speakers pretty well. And even the 2 ohm loads get an extra boost.
https://www.stereophile.com/integratedamps/633/index.html

zingo

That’s a nice little description in that article; thanks! I agree that most amps don’t like 2 ohms, but NAD circuitry is impressive.

mlistens03

My C352 can, according to spec sheets, run 240 watts @ 2 ohms with the soft clipping switch. Even though that is distorted power, that is an impressive number.

Tony M

I believe the stats at 2 ohms are for short term transients. Not for continuous output. I think most amps would melt powering 2 ohm loads.

Tony M

Here's a good article I just skimmed over VERY briefly.

I think it's supposed to described transient bursts also.
https://www.audioholics.com/loudspeaker-design/truth-about-matching-amplifier-power

alucididea

I have to say I really enjoy my NAD M22. Lots of clean power to spare.

pitdogg2

alucididea wrote: »

I have to say I really enjoy my NAD M22. Lots of clean power to spare.

Agree those first NAD M series amps had me seriously thinking of trying one. Lots of grunt from those.

alucididea

pitdogg2 wrote: »

alucididea wrote: »

I have to say I really enjoy my NAD M22. Lots of clean power to spare.

Agree those first NAD M series amps had me seriously thinking of trying one. Lots of grunt from those.

They’re pretty awesome. I’ve seen them refurbished for $1600 for the first series. Not a bad deal for such a low noise floor. When I audititiomed the M12 DAC, I couldn’t believe how much synergy the two have with one another.

pitdogg2

Yep the disc player was pretty nice as well. That series they didn't muck around they were very serious about it.