NAD M28 7-Channel Power Amplifier Review & Comments

Hmm, I thought that I had previously posted on this thread (hence my getting an email reminder for updates to the thread) but somehow my earlier, inoffensive, post seems to have vanished ...

Let's see if this post survives. This isn't a complaint againt this great-sounding NAD M28 amplifier specifically, but against all 7-channel amplifiers. Assume that you have a great deal of money, and a reasonable, though not endless, amount of space in your AV cabinet. You want to move beyond the previous standard of a 7.1.4 system to the new standard (which Mr Withers himself has at home) of 9.2.6. You have a 16-channel processor like the Lygndorf MP-60 or the Arcam AVR30 (which has seven Class G amplifier channels). My concern here wouldn't be the two subwoofers, but the nine base channels plus the six Atmos channels. Those come to 15 channels. And my point is that using seven-channel amplifiers, it's not possible to get to 15 channels with only one further box. If you used the Arcam, with its seven built-in channels, you still need eight more channels, which using seven-channel power amplifiers means two more boxes, or three in total. And using the Lyngdorf, with no built-in amplification, to get to 15 power channels entails using three seven-channel power amplfiers, or four boxes in total. Which is kinda a lot of boxes ... However, I guess that you could stick with three boxes in total even using the Lyngdorf processor by using this NAD amplifer for the base layer and then using something like the Emotiva XPA-11 (or its nine-channel version the XPA-9) for the other channels. Perhaps 8-channel separate power amplifiers might become more common in due course as we go beyond 7.1.4 systems.
I completely agree with you on this point Ken. In the modern immersive audio world, a 7-channel amp is arithmetically annoying. An 8-channel model makes more sense for the reasons you mention, or better still a 16-channel amplifier for a tidy single-box solution. It's for this reason that I've recently added the 16-channel Storm Audio PA 16 MK2 amp (review in the works) to run the 15 channels in my system.
 
I completely agree with you on this point Ken. In the modern immersive audio world, a 7-channel amp is arithmetically annoying. An 8-channel model makes more sense for the reasons you mention, or better still a 16-channel amplifier for a tidy single-box solution. It's for this reason that I've recently added the 16-channel Storm Audio PA 16 MK2 amp (review in the works) to run the 15 channels in my system.

The Pascal amps seem to be getting about a bit now. Dynaudio use them in their mega serious Core range too.

I’m looking forward to the review Steve.
 
Never had any issues with any NAD products I've bought over the years. My Dad still uses his 3020, bought over 40 years ago and its never needed any maintenance. Guess you guys were just unlucky. They make great products.
 
I am considering buying this amp. Did someone measure the power consumption? I am bit curious how the claimed 7x340W are possible, when the sticker on the back say 1200 W power consumption. In my world the power consumption has to be a good deal greater than the power output. Or do I miss something here?
 
Back panel stickers don’t usually show maximum power consumption, just a nominal rating power consumption for compliance purposes. Audioholics did a feature article on this a while ago.


As this PA is Class D with up to 90% efficiency, in theory it could pull off 7x340w from a 3kw/13A mains supply.
 
Nice feature. A little bit confusing, since some manufactures seem to print the maximum power consumption on the back.
 
I am considering buying this amp. Did someone measure the power consumption? I am bit curious how the claimed 7x340W are possible, when the sticker on the back say 1200 W power consumption. In my world the power consumption has to be a good deal greater than the power output. Or do I miss something here?
be limited by mains power supply at the very least .. whcih for us is 2400w ...and i note if you multiply 7x340 out its magically just below the 2400W max power draw possible from our 230V power sockets for instance .. however it doesnt allow for any efficiency losses :D

energy cant be created or destroyed ... also once factor in energy losses the max power is going to be just that .. flat out .. probably most distortion etc...

Not sure been any measurements, keeping in mind there seems so many ways power is measured … watts isn’t watts

1209/7 is still 171 and likely quality watts

The review states,

“A lot more power in fact, with NAD claiming the M28 can deliver 200W of amplification into 8Ω when driving all seven channels, and even hit dynamic peaks of up to 320W. Connect the M28 to 4Ω speakers and NAD claims the M28 can produce 340W into seven channels simultaneously. That's a serious amount of grunt in anyone's book!”

Which looks like a cut paste on discs posted on the nad site, so the 320w is a peak and dynamic figure … the 340w has not much else accompanying fir context bar that it’s simultaneous … no mention of distortion freq measured across etc …

Nad lists Specs below,

Headlining,
  • FTC power, two channels
  • ≥ 220 W (ref. rated THD, 8 Ohms , 20 Hz – 20 kHz, two channels driven)
    ≥ 400 W (ref. rated THD, 4 Ohms , 20 Hz – 20 kHz, two channels driven)
  • Rated power, all channels
  • ≥ 200 W (ref. rated THD, 8 Ohms , 20 Hz – 20 kHz, all channels driven)
    ≥ 340 W (ref. rated THD, 4 Ohms , 20 Hz – 20 kHz, all channels driven)
  • Rated THD (250 mW to rated power, C

The 200wpc certainly makes sense :) that’s going to be plenty and sounds like quality watts :)
 
be limited by mains power supply at the very least .. whcih for us is 2400w ...and i note if you multiply 7x340 out its magically just below the 2400W max power draw possible from our 230V power sockets for instance .. however it doesnt allow for any efficiency losses :D

energy cant be created or destroyed ... also once factor in energy losses the max power is going to be just that .. flat out .. probably most distortion etc...

Not sure been any measurements, keeping in mind there seems so many ways power is measured … watts isn’t watts

1209/7 is still 171 and likely quality watts

The review states,

“A lot more power in fact, with NAD claiming the M28 can deliver 200W of amplification into 8Ω when driving all seven channels, and even hit dynamic peaks of up to 320W. Connect the M28 to 4Ω speakers and NAD claims the M28 can produce 340W into seven channels simultaneously. That's a serious amount of grunt in anyone's book!”

Which looks like a cut paste on discs posted on the nad site, so the 320w is a peak and dynamic figure … the 340w has not much else accompanying fir context bar that it’s simultaneous … no mention of distortion freq measured across etc …

Nad lists Specs below,

Headlining,
  • FTC power, two channels
  • ≥ 220 W (ref. rated THD, 8 Ohms , 20 Hz – 20 kHz, two channels driven)
    ≥ 400 W (ref. rated THD, 4 Ohms , 20 Hz – 20 kHz, two channels driven)
  • Rated power, all channels
  • ≥ 200 W (ref. rated THD, 8 Ohms , 20 Hz – 20 kHz, all channels driven)
    ≥ 340 W (ref. rated THD, 4 Ohms , 20 Hz – 20 kHz, all channels driven)
  • Rated THD (250 mW to rated power, C

The 200wpc certainly makes sense :) that’s going to be plenty and sounds like quality watts :)
13A x 230V is actually 2990W ;).
 
Went ahead and ordered one and it arrived today. Wow, it looks really nice. Sadly I won't have time to test it before sunday. One thing I noticed, when I just checked, if the amp works: Without a preamp connected I have a fairly loud hissing from the speakers. With the preamp connected it's dead silent, even with the preamp switched off. Did not notice this with any amps I had before. Could someone please check, if their unit behaves the same?
 
Went ahead and ordered one and it arrived today. Wow, it looks really nice. Sadly I won't have time to test it before sunday. One thing I noticed, when I just checked, if the amp works: Without a preamp connected I have a fairly loud hissing from the speakers. With the preamp connected it's dead silent, even with the preamp switched off. Did not notice this with any amps I had before. Could someone please check, if their unit behaves the same?
How you getting on with the M28 did you resolve the issues - thinking of adding one to my 778
 
Hello
I had a M28. Great sound. Great looking box that ran very cool.

BUT had my first problem out of the box.
1 channel would pop. The service took 3 months, they change a channel.

After 7 months, 2nd problem. The unit wouldn't turn ON. Service repair took 2 months.
I opened the pack, turned on the amp and heard poping noise again, and then BOOM the amp loterally exploded (well a capacitor I believe).
After two more months and a LOT of arguying they sent me a brand new one.
I am not sure wether I am going to open it...
So please M28 users (there does not seem to be a lot), do you have problems with your units or did I receive a dud ?

Thank you
 
The Pascal amps seem to be getting about a bit now. Dynaudio use them in their mega serious Core range too.

I’m looking forward to the review Steve.
I've got the Core range in my office and they are bomb proof. The Core Sub is stellar ! They don't get too hot either.
 

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