Mediocre measurements for new Sonos Amp

This article confirms that the Amp is using the Qualcomm DDFA chipset, which offers outstanding digital performance. It's certainly possible that the 70ms delay confused the tester's analog input measurements, but who knows...

https://www.cnet.com/reviews/sonos-amp-preview/

The Amp doesn't include the digital-to-analog converter found on most of its kind, instead using a Qualcomm DDFA amplifier, which keeps the signal digital until the last possible moment. The analog input still features an analog-to-digital converter though, and the signal -- say of a record player -- can be streamed to other Sonos units in the home.

I too suspect the line levels were set at the default, which for mine was I think level 2. At level 2 with the volume turned all the way up, the music didn’t get very loud at all. I have since experimented and it is now set to level 7 which gives me volume more than I’m comfortable with.

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/

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?

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...

The analog input SNR measurement after he changed the software setting was 87 dB at 5W.
I found nothing in the review that indicated he'd adjusted the Line-In gain in the Sonos app. What I did observe was a general lack of knowledge of how to use Sonos.

So probably you will not hear the noise.

I'm sure that's true 🙂

He said he bumped the setting up from 2 to 3 (maybe he clarified this in the comments that followed the review). He said that anything higher than 3 resulted in clipping when he used his test signal.
Ah, it's there now, on page 3 of the comments. Thanks. That makes sense: with a 2V signal, that would be at the top end of normal for the Line-Out of an audio separate like a CD player. In fact, I wonder whether he should have left it at '2', and not '3'.

I agree. It appears the line in performance does not measure well but the streaming side of things is fine. The convenience it brings is incredible. There are not many reviews that measure measure the sonos amp so it is nice to have this.

I'm an owner of the Sonos amp but not super defensive about it. Many things weren't measured or done in a methodical way and lots of things unmeasured. Plus the conclusions aren't clear.

Nice breakdown of the technology here:
https://www.theverge.com/circuitbreaker/2018/8/29/17791754/sonos-amp-new-price-features-release-date-hdmi-arc-tv-audio-speakers

As for the nitty gritty of what’s inside...

The modulator is a DDFA (direct digital feedback amplifier) class D amplifier.

Sonos built its own custom discreet output stage because there was no off-the-shelf part that could balance efficiency and heat management inside the Amp’s tightly-packed chassis.

Similarly, it uses a custom power supply designed to fit into the form factor and to provide clean audio output. The Amp’s signal to noise ratio is 116dB with under 0.1 percent total harmonic distortion.

Rappoport said Sonos engineers and designers “combined the functionality of the heat sink and the chassis, and we ended up mounting all of the electronics onto a single heat sink. The digital electronics, the analog electronics, even the antennas are mounted to the perimeter of that heat sink, and then the enclosure comes down around it.”

The speaker connectors are custom, removable thumb screw-style banana plugs that can be swapped out if you prefer standard banana plugs. They accept 10-18AWG speaker wire.

Rather than force people into using its own Sub speaker, Sonos retained the sub output on the Amp for flexibility. “We don’t make an in-ceiling sub. We don’t make an in-wall sub,” Rappoport acknowledged. “If we want to give choice to deliver architectural sound experiences, we knew that we had to provide that provision.” An advantage over the Connect:Amp is that users can adjust crossover on the new Amp between 50 and 110Hz (in 10Hz increments).

There are two ethernet jacks; the second can be used if you want to hard wire another Sonos device. The Amp also includes 802.11 b/g/n (but not ac) Wi-Fi if you prefer that over ethernet.

That plastic horizontal strip at the bottom is an IR sensor. Because everything needs an IR sensor.

Hello to everyone, I agree with almost all comments, I use the line in often and I have to play with the settings a lot to get the results I like. What I am gonna add is that this reviewer claims that most high end audio doesn’t even approach the figures claimed by audio companies, debatable or not if we see a different review:

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-monoprice-hybrid-tube-amp.7513/#lg=attachment25967&slide=0

The sonos amp through streaming is in fact over most of the equipment checked on that forum, I also agree somehow with the review regarding the line in because I struggle a bit make it work to my taste. I also do things in a similar to the reviewer, as I do not own a turntable but use a usb dac to feed a valve amplifier that I use as preamp. Btw, it works. So I am sure the reviewer could have found the ideal conditions to use the line in like for example the ideal voltage in and other settings but that is outside the reviewers procedure scope and I myself do not know about technicality, if so I would have a full of ports Rega analog amp and not a Sonos ;)

I find the “audio science review” very bias as it losses the plot talking about voice assistants, yet I find it useful as even being bias the reviewer refuses to cast an opinion and leaves you with the figures and the procedure used.  I find that fair, after all the Sonos amp which I really like could be a more divisive product than for example the Sonos one.