Sonos Amp, we tested the most versatile and powerful amplifier and player

The Sonos family continues to grow and last summer the American company announced its Sonos Amp. Unlike their other products, this one doesn't "sound" on its own: it needs speakers. But there is also its grace, by allowing us to take advantage of some boxes that we already have , or buy better ones. Thanks to that, it does not limit its benefits to the included speakers: it will depend on what we connect to it. It is, therefore, the Sonos with the greatest sound potential, thanks also to its 125 W enough to move almost any box. It costs 700 euros and we have been able to test it thoroughly in different configurations. We can anticipate that we have been very pleasantly surprised: there is no other similar device that offers so much.

Background and possibilities

A similar product already existed, the Sonos Connect: Amp, which was previously called the ZP120 (year 2005). That is, a Sonos device with all its possibilities, but without speakers. Its internal amplifier could power whatever speakers were, although it had only 55 W of power. The Sonos Amp boosts that up to 125W and does so in a slimmer chassis thanks to Class D technology. 21st century amplification, quality, efficient and with hardly any heat. With any two speakers of the quality we want (or can afford), we can have a first-rate sound system.

But the Sonos Amp brings some new tricks. One of them is the versatility of configurations that it allows, thinking about mounting a home theater system. Logically, and like other devices in the family, it allows using a pair of Sonos as surround back effects speakers. It's one of the things we tested, because in addition to the Amp they lent us two Sonos One  for this article.

If we wanted to use non-Sonos speakers for surround, that is also possible. But we need a second Amp, which will be the one that sends the amplified signal to those speakers. Yes, it is possible to sync or connect two Sonos Amps to form a theater system, as we would with other Sonos products. There is still another way to use it, if we are going to sound for example a room and a terrace. The speaker outputs in that case will be two “monaurals” (not stereo) and each could feed two speakers. In this case, it is not intended to generate a stereo sound scene but to give sound to two environments, perhaps with built-in speakers. Precisely Sonos is selling this type of speakers in an agreement with the Sonance specialist , but that's another story.

Sonos Amp (foreground, B&W 802D cabinet)

Compact and capable

This compact black box only measures a square foot (22 centimeters) by only 6.4 cm high. By the way (despite the success of some Sonos products in white) it is not available in another color. Its little more than 2 kg of weight hide a lot of electronics including the aforementioned amplification modules . Class D works in switching and allows to reduce space occupied, weight and dissipated heat. The front has the usual Sonos Led and the already familiar three touch controls. With them we can advance or rewind songs, stop and raise or lower the volume. For the rest we need the Sonos App, very complete and easy by the way. Well, or the remote control of the connected TV, which can be synchronized (very practical).

The Sonos Amp delivers up to 125W of power at 8 Ohms (normal speaker impedance). But it can power 4 Ohm speakers, hence we can connect two to each output. Like when we want to sound a larger space for example. The lower part is a grill that allows fresh air to enter, and the upper part has a circle with a slot through which hot air is evacuated. Without fans, the Amp stays warm in use even at high volumes.

Correct connectivity

In addition to everything that we can do through the network (it has Wifi 802.11 b / g / n) the Amp has several rear connections . There are two Ethernet, in case we want to deactivate the Wifi and use the wired Sonos. By having two, we could "chain" devices. Then there are the speaker outputs, for a couple, in standard “banana” format (4mm). If we need to use bare wire, good quality adapters are attached (and looks, design always counts). We also have an RCA output for a bass cajon if we don't have a Sonos Sub, which would work via network.

The two inputs are important: one, analog RCA stereo (for a turntable for example). The other, an HDMI showing Sonos intention that we use the Amp near a TV. In that case, the HDMI-ARC signal would arrive as with the Sonos Beam or PlayBase that we already tested at the time. If our television is old and its HDMI does not have ARC, Sonos has an adapter to use the optical digital output. It's a good solution but on the back of the Amp there is plenty of room for one (or two) digital inputs. It seems to us a failure that it does not have itFor that or for a CD or Blu-Ray reader for example. We also do not like that (like all Sonos) it does not have Bluetooth (practical even if only). And on demand, a front auxiliary input (stereo jack) would be welcome as an alternative to the solitary rear RCA.

Limitations

Note some limitations of the Sonos Amp . To begin with that limitation by the digital input to the HDMI ARC (Audio Return Channel audio output). We can find ourselves with two-channel sound instead of surround: we depend on what the TV sends. Anyway, let's remember that the Sonos system has its limitations: at most it supports Dolby Digital 5.1 (not DTS, or of course Atmos or anything higher). Even if you receive DD with 5 + 1 channels, the Amp will be able to reproduce 4.1 channels at most. It has no amplification or output for a center, nor is it planned to use another Sonos speaker in that position. In return, the Amp uses digital processing to generate a virtual center channel (called “Phantom” or phantom) from the two front stereos.

On the other hand we have the limitation to CD quality stereo sound . The Amp can be the protagonist of a stereo system that can potentially be of high quality. It will depend on which speakers we connect and from which source it is powered. But the Sonos system does not reproduce any high resolution sound format: not those that use Tidal (MQA) or Quobuz (Hi-Res) for example, nor others. Not related to sound, another limitation of the Sonos Amp is in the use of assistants such as Siri or Alexa. The latest Sonos products (One or Beam) have been noted for including responsive and efficient microphones for receiving spoken commands. But (strangely) the Amp does not have any of that : it will depend that we have other compatible devices connected.

Let's do it

The messenger left us two boxes: in one came the two Sonos Ones, in the other the Amp. As always, it is a pleasure to unpack products as well presented as the Sonos … very “Apple style” let's say. Great detail is the fabric cover that protects the device itself and that we could use as a dust cover later. The Amp itself is a less conspicuous product than other Sonos: it doesn't “ring” and it doesn't have speaker grilles. But the finish (black only) is flawless, satin, and the top vent is eye-catching. Like other Sonos it has three touch controls but no disconnect. After a few minutes of pause, it automatically goes into low power sleep mode.

The connection, as simple as with other Sonos. We plug it in and open our own App (on iOS or Android). Soon the expected green light appears and we proceed as indicated by the application itself. And in a few minutes it will be connected and updated , in this case without a problem with the Wifi. The next step is to search for sound sources: with the Amp we could have connected a television via HDMI. Also any somewhat digital source (CD, DVD etc.) with the optical-HDMI adapter. In analogue (stereo RCA input) any source, although if it is a turntable, the corresponding phono preamp will be required. But the strength of Sonos is its compatibility with virtually all online music services.

Online music

An important good thing about the Sonos is how versatile its control application is . We can quickly listen to any Internet radio, with a good selection of our own by style and country. It's easy to connect to and browse our shared home library. And above all, it is easy to use the other means of listening to music: streaming services. Americans have made sure that it is simple and compatible with as many music services as possible. The list is endless, with more than forty services. Our favorites included, of course: Tidal, Spotify, Quobuz, Apple Music, even recently YouTube Music.

The application we use the most as it offers music with lossless compression (FLAC) is Tidal. And also Spotify, whose lists are the best. Tidal menus are seamlessly integrated into the Sonos app, favorites are easily accessed, and you can choose favorites that the app saves. The same with Spotify, we only have to register our user and the connection works from then on in a transparent way. By the way, there is not only a mobile or tablet App, but also for the computer(Mac or Windows). And the latter is very practical in the case of the Amp, it came in handy for us when we had it in the room-office where we write. In addition to the complete program, it allows you to leave a floating window as a mini-player where it shows what it sounds with basic controls (perfect).

Multiple tests in one

Given its versatility and possibilities, we have tested the Sonos Amp in different equipment and situations. Above all, we have tested it with different speakers to see how much it can perform and how far it goes. The "logical" seems to be tested with speakers in its price range, but in sound that logic does not always apply . Often times, the speakers that have a price commitment also have it in other facets: for their sound, or for their performance and ease of amplification. There are speakers whose price multiplies that of the Amp but that do not need a lot of power to give great sound, for example. And instead some inexpensive speakers demand a lot from the amplifier.

That's why we've tested the Sonos amp and player with different speakers . On the one hand our B&W 802D and also some of high sensitivity easy to amplify (Ramallo Allegro). More balanced (in price) were our B&W CM5 and CM1, of shelves. Also the Monitor Audio Gold 200 5G that we had for another test. In some of these cases we complement the Amp with a pair of Sonos One as butts to watch movies, and also with its own bass caisson.

The sky as the limit

Although a more extravagant combination of speakers and amplifier or source would still be possible (in audio, the sky is the limit…), the fact is that the combination with our best specimens was a success . We tested the Sonos Amp in a room of about 30 square meters with the aforementioned B&W and Monitor Audio. And also in a basement with better acoustics and high-performance cabinets (designed for tubes and low power). We will reveal the result immediately.

In both cases it was great to be able to try, in addition to stereo music, some cinema. It was enough to move the two Sonos Ones and activate them for surround sound in the app. You just have to find where to plug them in, without any more hassles of cables or configuration ... The truth is that this facility is unique to Sonos and that the speakers are so versatile, it convinces. Because you can have that couple of One serving as "envelopes" in winter and take them out to the terrace in summer for example.

With movies or series, the truth is that the Amp and the One defended themselves very well. In this case, if we add the necessary front speakers and the recommended bass box, we put ourselves on a medium budget. Let's say it rivals a traditional home theater receiver and low-end boxes. The Sonos Amp offers more facilities and the receiver greater connectivity. As for sound it may depend on the material but the Amp and the One defended themselves very well. Maybe it helps that they are active and sound "bigger" but some surround effects were very striking with the One. In horror or suspense movies, for example, we get a scare when we hear sounds from behind ...

Pure stereo

But if the system performed very well in cinema, it was in stereo that we were most surprised . The Sonos Amp would surely not be the first on the list of a music lover looking for a serious equipment. We refer to a system in front of which you sit down to enjoy music, to which you listen carefully. And yet he showed us to be perfectly capable of assuming that role, apart from being optimal for listening to music in a more distracted way. We had pointed it out above but the combination of a sufficiently capable amplifier with quality speakers is a winner.

One point in favor of the Amp is its extremely low noise level . Even with the high-performance boxes, we don't even hear background noises with our ears glued. And with these boxes the sound was dynamic, happy, detailed but without aggressiveness ... they flew with the compact Sonos. We can say the same about its association with boxes as unlikely a priori as the Bowers 802D. Its price is thirty (yes 30) times that of the Sonos Amp… and yet the partnership was a success . The openness and cleanliness of sound in mids and highs had a perfect foundation in bass. The soundstage projection had nothing to envy amps many times the price of the Sonos. Only a trained ear would appreciate a little less subtlety or transparency in highs and less punch in lows.

Sonos Amp with B&W CM5

A surprise, in short, the level of sound that can be achieved with the Amp and appropriate speakers . We listen to common tracks and discs in other tests of more “specialized” sound equipment without missing better sound quality. And in some cases, we have heard those same songs or tracks in systems that force us to mortgage the house to pay for them, with that it is said how high the single Sonos Amp is capable of pointing in good company.

More logical boxes

The combination with the B&W monitors, more similar in price to the Sonos Amp, was also at great height. The larger CM5s in the living room breathed as they do with much more expensive stereo or theater amplifiers. The 30 square meters were filled with music with the Sonos even at higher volumes than recommended. Before they were the protagonists of cinema moments with the Monitor Audio columns and always with the Sonos One as "envelopes".

Interestingly, with the smaller speakers we did notice differences when adjusting the sound options of the Sonos. In "settings" you have to go to "rooms" and "EQ": in addition to bass and treble there is "loudness". With Sonos speakers this setting is very evident: in general, totally recommended, because it “fills” more and the music or voices take on more body. But with the Amp it seemed very subtle, or inactive, this setting. Until we tried the smaller boxes. There we do recover that feeling, and we prefer the activated setting except with very loud music.

In the case of the more compact CM1s, in their case accompanied by a bass box, we were able to see how well the Amp knows how to combine both types of boxes . It has a menu for that, in "Advanced sound" the "Sub settings". It allows activating or deactivating it, regulating the output level and also the important crossover of frequencies. There, between 50 Hz and 110 Hz depending on the size and capacity of the main speakers, we choose where those notes will go. We cut the CM1s at 80 Hz and the set sounded great, bigger box. The Amp sends the normal musical signal to the snares but diverts the bass to the snare to optimize the sound.

The only thing that is not available is Trueplay . In other Sonos, after measuring the acoustics with the mobile microphone, Trueplay adjusts its response to optimize the sound. Since they don't know which speakers we connect to the Amp, they haven't included it. In our opinion, this is precisely why it would be more necessary! It may be available in a future update, because in our experience it is something worth having and activating.

Conclusions

We didn't know exactly what to expect from the Sonos Amp before testing it. Its predecessor had just enough power for many speakers, but the Amp does pack a lot of potential in its compact box. We would have liked it to have wider connectivity: there are only two inputs, and the speaker and subwoofer output. It is little, very in line with the minimalism of these products. In return , access to music through the network is almost infinite , and the application is simply perfect.

Combined with well-chosen speakers it can deliver a level of sound that is simply unexpected. You could be the lone star of a very high-end system only using appropriate boxes, your budget, or even well above. We tried both options and were never disappointed. With any type of music we do not miss much higher priced electronics. Also, like a good Sonos, everything works the first time as in its speakers and other products. And it's a pleasure to unpack, install, view or touch it. If we have good speakers and we don't want to buy Sonos, but we do want their system, the Amp is the solution. And if we want to build a team from scratch, this can be a perfect solution. An excellent product that finishes off a great range and without a doubt the best home sound system, for one or for several rooms.

Sonos Amp