Mediocre measurements for new Sonos Amp

According to this article, Sonos specs the SNR at 116db, which puts the noise WELL below audibility. They certainly can't lie about that, so this guy is simply not measuring correctly. Perhaps Sonos' engineers should show him how to do it correctly.

https://hometheaterhifi.com/blogs/sonos-amp-review/
But Sonos does not include that 116dB spec in their own literature. Someone from Sonos should reply here and clear this up.

I see his measurements of the Bluesound Node are pretty mediocre, as well. Something just doesn't seem right with his measurements.

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-bluesound-node-2i-streamer.6631/

I just started reading it, but it reads like someone who knows nothing whatsoever about Sonos - not familiar with daisy chaining Ethernet or using it as a bridge, unaware of several previous Sonos products with inputs. And what’s that crack about the custom power cord? I guess I’ve never tried other cords but I always assumed they were standard figure 8 size. Is the Amp not standard size?

If sonos has data that proves these measurements wrong then lets see them. I have more invested in sonos than most - 3 Connect Amps, 1 Connect, 1 Play 5 Gen 2, Pair of Play 1s with sub and currently have a pair of play1s and a spare connect amp and connect in storage but I would like to know that technically the units measure well especially if you are a company that speaks of engineering excellence.

Sonos is likely measuring SNR under different conditions. In the ASR review, SNR was measured at 5W output. SNR may be much better when the amp is putting out more power. Also, A-weighting may a factor.

It would be helpful to hear from them.

If sonos has data that proves these measurements wrong then lets see them. I have more invested in sonos than most - 3 Connect Amps, 1 Connect, 1 Play 5 Gen 2, Pair of Play 1s with sub and currently have a pair of play1s and a spare connect amp and connect in storage but I would like to know that technically the units measure well especially if you are a company that speaks of engineering excellence.
Why are these measurements so important to you? If you are not happy with what your ears tell you, why do you keep buying Sonos products then?

Here is an interesting white paper on the NAD M32.

https://nadelectronics.com/wp-content/uploads/2017/03/DirectDigital_WhitePaper.pdf

This is the same technology that Sonos uses in the new amp. The 2nd page talks about SNR at full power and at normal listening levels. Considering this, the Sonos amp streaming SNR number, measured in the ASR review to be 92dB @5W, are good. Not as good as the much more expensive NAD M32 but the Sonos amp is not measuring poorly. The amp's SNR (again 5W reference) with analog input is a little worse at ~87 dB, but still not bad.

Assuming this French site is correct, Sonos is using Qualcomm DDFA chips:
https://translate.google.com/translate?hl=en&sl=fr&u=https://www.lesnumeriques.com/ampli-audio-video/sonos-amp-p45781/ifa-2018-sonos-presente-amp-son-amplificateur-stereo-connecte-n77667.html&prev=search

From the Qualcomm DDFA literature:
A unique and patented digital architecture delivers market leading audio performance across the entire audio frequency band delivering:

SNR and Dynamic range > 113dB (A-weighted, 20Hz to 20KHz)
THD+N < 0.005% (20Hz to 20KHz)
Closed-loop operation and high-resolution DSP helps maintain performances at all times:

Distortion does not increase at maximum volume like many other amps
No audible noise or hissing sound
Performances are maintained across a wide range of audio input formats


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This guy apparently doesn't have the ability to measure via digital inputs.

So, either the ADC in the Amp has issues, or he's measuring something wrong. My money's on the latter...

Here's an amplifier that appears to use the same Qualcomm chipset, with measurements using an Audio Precision analyzer.

http://www.elytone.com.tw/odm_oem/index.php?route=product/product&path=57&product_id=153

Note that THD+N is 0.005% across the audible band.

Yes but Sonos specs THD+N at 0.1%. I assume that is 0.1% at 1W, which agrees with the measurement in the ASR review.