Sonos new Standalone amplifier is out and some of the reviews are starting to come in. For those not familiar with the idea, the Sonos home audio system started out with a standalone amplifier - The ZP100 (later called Sonos Connect:amp). This standalone amplifier was controlled via their wireless controller and had 50w per channel of stereo music available. Later Sonos added an app, an unamplified version to connect to your current hifi (the ZP 90) and amplified speakers in the from of their PLAY and SUB and PLAYBAR range.

Earlier this year Sonos announced that they will be revamping the design of the Sonos Connect:AMP to fit in better with the new lineup. They promised higher power figures, better sound and easier integration into equipment racks and custom installations.

Simon Cohen from Digital Trends now has a review up;

More power, more options: Sonos’ Amp is a worthy upgrade for your speakers

The sexiest, sleekest way to convert conventional speakers into modern marvels.

Sonos new ZP100 Amplifier

Sonos new ZP100 Amplifier

AirPlay 2
Rich, full sound
Slick, sophisticated design
Custom installer friendly
Can power even large speakers

Not ideal for home theater
No adapter for optical audio

Sonos’s very first product was the ZP100, a bookshelf-class amplifier with built in Wi-Fi that you could connect to virtually any speakers. It was the product that established Sonos’s reputation for simplicity, reliability, and sound quality, and it made wireless digital music in the home a reality. The ZP100 was eventually renamed the Connect:Amp, and although its software has been updated constantly over the years, physically it has remained largely untouched. Over the years, the company has been on a tear, introducing a slew of self-powered speakers, soundbars, and a subwoofer — all of which have proven popular with consumers. So popular in fact, that the humble Connect:Amp ceased being a go-to product for consumers, and started attracting an entirely new audience: Custom AV installers.

It makes a lot of sense. The Connect:Amp is the one product that will let AV pros give their customers all of the simplicity and convenience the brand is known for, using custom-installed architectural speakers, in walls, ceilings, and even outdoors. So it was with this stakeholder in mind, that Sonos embarked on a redesign of the Connect:Amp. Enter the all-new $599 Sonos Amp, a product that is both a re-imagining of what the acclaimed Connect:Amp offers consumers and an effort to make the product even friendlier to AV pros who have attached their reputations to the Sonos brand. Does it succeed? Here’s our Digital Trends review.

SONOS New ZP100 Home Audio Amplifier

SONOS New ZP100 Home Audio Amplifier


The Connect:Amp, unlike the majority of Sonos’ products, only came in one dress code: Silver and white. The new Amp, on the other hand, comes in any color you want, as long as it’s matte black. Though this choice will inevitably tick off some customers who have become accustomed to buying Sonos products in a range of colors, we think it looks great.

Its low and wide stance, combined with its unique circular indentation on the top surface, pulls off a neat trick: Sitting on its own, or perhaps beside a turntable, its monolithic shape lends an instant air of high-end sophistication to any room. Added to the top of a home theatre component stack, it blends into its surroundings, all but disappearing.

Other than a single LED and subtle touch controls which grace all new Sonos products, no other feature interrupts the Amp’s visible surfaces. Even the IR receiver — a tiny sliver of a window at the bottom — is virtually invisible. If there’s one nitpick, it’s that the matte finish is a dust and fingerprint magnet.

Closeup of Sonos New ZP100 Stereo Home Audio Amplifier

Closeup of Sonos New ZP100 Stereo Home Audio Amplifier


That circular indentation isn’t just for looks: The Amp is intended to be stacked when the need arises, and that round groove mates perfectly with the device’s circular rubber foot. In fact, all aspects of the Amp — from its height, width, and depth, to its thermal dissipation properties, to the linear arrangement of ports on its rear panel — were created to make it far friendlier than its predecessor for use in an AV rack, the tool of choice for AV installers looking to keep their customers’ gear neat, yet accessible.

Sonos Amp comes equipped with AirPlay 2, making it especially great for streaming video apps like Netflix or Youtube.

You can fit two Amps side by side in a 1.5RU rack slot, or, you can stack them as tall as you need. Unless you’re running all of them at maximum power for many hours at a time, they should be able to keep their cool. If they don’t, a sensor will keep them from melting down.

If you want a third option for mounting the Amp, it has been designed with wall-mount applications in mind. The bottom of the enclosure has a threaded hole, suitable for use with hardware like this Sanus-developed wall mount bracket.

Sonos ZP100 Home Audio Amplifier - Rear Connections

Sonos ZP100 Home Audio Amplifier - Rear Connections


The Sonos Amp still fills the same role as the previous Connect:Amp in that you can connect up to four non-powered speakers and a powered subwoofer, and it gives you a set of RCA analog inputs for an external audio source, like a turntable. But the Amp has grander aspirations than its predecessor. The 55 watt-per-channel Class-D amplifier is gone, replaced by a much more powerful 125 watt-per-channel unit. Sonos claims this beefier amp is enough to power full-size floor standing speakers, and though we didn’t get a chance to test that claim, based on the power it was able to throw at our mid-size speakers, we don’t doubt it.

Sonos is also hoping that buyers will consider using the Amp as the basis of a home theatre system, and has given it an HDMI-ARC input so that you can connect it to a TV. In the same vein, you can control the Amp’s volume using a universal infrared remote — a feature it shares with the Sonos Beam soundbar.

It even has a very clever set of hybrid speaker terminals. With included adapters, those with bare-wire speaker cables can use a standard screw-down locking system. It’s not as convenient as the Connect:Amp’s spring-loaded terminals, but it’s arguably more secure. Or, if you’ve installed banana plugs on your wires, you can ignore the adapters and plug directly into the back of the Amp, which makes for a super-clean and low-profile install.

Sonos ZP100 amplifier Speaker Posts

Sonos ZP100 amplifier Speaker Posts


Sonos Amp also gains AirPlay 2 functionality, something that Sonos has added to all of its most recent products including the Beam, and the Sonos One. For music listening, this isn’t a big deal as the Sonos app has always been able to access a device’s local music storage. But for streaming video apps, like Netflix, YouTube, or Amazon Video, it’s a major benefit. Listening to the soundtrack of a Netflix series like Stranger Things on a superb sound system (even a 2.1 system) is way better than on the terrible speakers on your phone or tablet.

Finally, the new Amp enables an optional mono mode, something the Connect:Amp didn’t offer. For the average consumer set-up, using a 2 or 2.1 speaker configuration, this isn’t a big deal, but AV installers will love it. Jeff Gosselin, owner of Toronto-based custom AV shop, Cloud9AV, tells Digital Trends that being able to drive up to four ceiling speakers in mono mode is critical for being able to fill a room with music that sounds complete, no matter where you’re sitting or standing.

Left and Right Speaker ports for Sonos new Stereo Amplifier

Left and Right Speaker ports for Sonos new Stereo Amplifier


We’re not entirely sure what to make of the Amp’s home theater credentials. You could, in theory, create a compelling 5.1 system with the Amp, but not on its own. To do that, you’d need either a Playbar, or a Beam acting as a combo front left+center+right set of speakers, a Sonos Sub, as the “.1,” leaving the Amp to power a wired pair of rear surround speakers. That’s not only awkward, it’s expensive.

There are other possible combinations with the Amp, like a 4.1 setup where the Amp takes on front right and left duties, along with a powered sub of your choosing, while a pair of Sonos Ones, Play:1s, Play:3s, or Play:5s get synced as rear surrounds. We tried this one out, using a set of Energy Connoisseur CB-5 speakers up front, Sonos Ones around the back, and an Energy sub. The sound was good — much better than we thought it would be given the lack of a center channel — but not as good as our standard 5.1 setup running through a dedicated Pioneer VSX-933 AV receiver, a device that sells for $200 less than the Sonos Amp.

Another quirk in the Amp’s home theater aspirations is the lack of an optical input. HDMI-ARC is great, (when it works) but we question why it’s being used exclusively. So far, no Sonos products can decode Dolby Digital Plus, which requires HDMI to pass its signal. Standard Dolby Digital 5.1 surround doesn’t need HDMI and works very nicely over TOSlink.

Overall sound quality was a significant step up, with clearer vocals and much better definition through the mids and bass.

All new TVs are equipped with an HDMI ARC port, but plenty of older ones don’t have one. The Sonos Beam ships with an optical to HDMI adapter, which neatly side-steps the whole issue, but the Amp does not. When we asked the Sonos team about this, they told us, “the percentage of users who will need an optical to HDMI adapter is thought to be relatively low. Unlike Beam, where (almost) every user will attach to a TV, Amp is more often a standalone sound system.” Sonos sells the adapter separately for $25, which is a bargain for such a handy device.

Gosselin points out that for installations where a TV is only connected to a 2.1 sound system, having ARC is very helpful. The Connect:Amp had no digital input at all, forcing TV connections to be all-analog (when the TV had analog-outs) or worse, digital-to-analog, using a third party DAC. Using ARC over HDMI also eliminates lag that could creep into the DAC process.

New Sonos ZP100 Amplifier inputs

New Sonos ZP100 Amplifier inputs


While we’re obviously a bit ambivalent about the Amp’s new role in the home theater space, we’re unequivocal when it comes to using it for its original mission: It’s a fantastic 2.1 amplifier, perfect for pairing with a turntable, or just streaming from Spotify. Our first test case was to see how the Amp performed when we compared it to a $200 Monoprice tube amp mated with a $350 Sonos Connect, running through a pair of Wharfdale Diamond 220 speakers and Klipsch powered sub. We hoped that we would hear more than a $50 difference, and we weren’t disappointed.

Overall sound quality was a significant step up, with clearer vocals and much better definition through the mids and bass. The soundstage became simultaneously wider and deeper, an effect we have gotten used to with Sonos speakers over time — they consistently punch above their weight class — and apparently Sonos’ magic works with third-party speakers too.

Bringing vinyl into the equation via a Pro-Ject Carbon turntable and matching pre-amp proved just as satisfying.

The Sonos app also gives you the option to adjust crossover frequency and phase when using your own wired subwoofer.

Still, expectations should be kept in check: While the Amp performed very well compared to a $200 Monoprice amp, with 8-ohm speakers, it wasn’t able to keep up with a much more expensive $900 Audio Control Rialto 600 amp, powering 4-ohm speakers. This won’t surprise audiophiles, but it’s definitely something to keep in mind: Although the Amp packs more power per channel than its predecessor, and can drive much larger speakers as a result, it’s still not a truly high-end amplifier.

Underneath the Sonos ZP100

Underneath the Sonos ZP100


We won’t say too much in this review about the ease of setting up the Amp. Sonos has this process down to a science, and as with all Sonos products, connecting the Amp to our system was almost laughably easy.

One area that will be a novelty to those who have only used the company’s speakers is the lack of a TruePlay tuning option. Sonos claims this is because it can’t truly know the acoustic properties of the speakers people are using with the Amp, so there’s no way to know what effect the software tweaking will have. There’s a bright spot on the horizon however — Sonos plans to partner with Sonance to produce a new Sonos Architectural line of speakers, which will enable TruePlay tuning when used with the Amp.

In addition to the standard loudness, bass, and treble EQ controls, the Sonos app also gives you the option to adjust crossover frequency and phase when using your own wired subwoofer. Normally, we’ve preferred handing over more of the low frequencies to the subwoofer when running the Pioneer VSX 933 receiver, but the opposite was true when using the Amp. The Sonos team suggested that this could be thanks to the fact that the Amp “has relatively more power to drive low-frequency signals into the speakers,” which seems as good an explanation as any.

One thing we would like to see Sonos do on the Amp’s EQ in a future release is offer a series of presets that could mimic the sound of different amplifiers. Tube amps are revered for their “warmth,” so it would be fun to see what software magic Sonos could achieve with a Tube Amp setting — if they can make a $200 speaker sound like a $400 one, maybe they can make an all-digital amp sound like an analog one.


Like the older Sonos Connect:Amp the new Sonos Amp isn’t for everyone, but those looking for a dead-simple was to stream music and even movie and TV audio with authority will find this piece a great addition to their favorite speakers.

Is there a better alternative?

Perhaps. One of the big benefits to using the Sonos Amp, and the Connect:Amp before it, was the ability to harness the power of a Sonos system through your own speakers, including volume control. You simply couldn’t do this as effectively by mating a Connect to third party amplifier. But this is changing. New receivers on the market are equipped with “Works with Sonos” certification, which means that if you hook them up to a Sonos Connect, the Sonos app can take over the volume control of the receiver. Given the Sonos Amp’s so-so performance as a home theater receiver, if you primarily want Sonos functionality in your media room, via your 5.1 (or greater) speakers, a Works with Sonos AV receiver might be a better option.

We would also be remiss if we didn’t mention Denon’s HEOS competitor: The HEOS Drive. It’s a rack-mountable, 4-zone, 480-watt system. Granted, it’s $2,500, but that’s only $100 more than four Sonos Amps. Nonetheless, we don’t think that Denon’s whole-home wireless sound system is as well thought out and as easy to use as Sonos, despite having a few features that Sonos lacks, like high-res audio support.

How long will it last?

If there’s one thing we can tell you about Sonos, it’s that the company is obsessively loyal to its customer base. Product quality is top-notch, and the company has yet to drop support for any of its legacy audio products. That’s an impressive thing to say about any tech company, let alone one that has been selling its products for almost 20 years. We expect the Sonos Amp will last a very, very long time.

Should you buy it?

If you were thinking of buying a Connect:Amp, and if you don’t own full-size speakers, or care a lot about AirPlay support, we suggest grabbing one while Sonos is selling out its remaining inventory. It’s $100 cheaper than the Sonos Amp, and you likely won’t hear a big difference. For everyone else, especially custom installers looking for dead-easy, and customer-delighting solution, the Amp is a great upgrade. Its home theater chops may not wow you but having the flexibility of IR control and HDMI-ARC could come in very handy for certain scenarios where a TV is part of the overall solution. Its 125 watt-per-channel power lets you drive everything from the smallest ceiling speaker to the biggest tower, and everything in between, which means you no longer need to supplement a Sonos Connect with a 3rd party amp, just to get the sound you want.”

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