Reviews of Attainable Hi-Fi & Home-Theater Equipment

Reviews of Attainable Hi-Fi & Home-Theater Equipment

Reviewers' ChoiceThe Austrian manufacturer Pro-Ject Audio Systems was founded in 1991 by Heinz Lichtenegger. His first product was the Pro-Ject 1 turntable, launched as an antidote to that era’s CD players, which still suffered from poor sound quality. Pro-Ject now makes an extensive line of turntables, some with USB outputs and built-in phono stages, and over the years has gradually expanded its offerings to tonearms, loudspeakers, accessories, cables, and electronics such as amplifiers -- even CD players. Today, their range of products is one of the widest I’ve seen -- you name it, chances are they make it at one of their two factories, one each in the Czech Republic (turntables) and Slovakia (electronics).

Interested in Pro-Ject’s integrated amplifiers, I requested a review sample of the MaiA DS2 ($1199-$1350, all prices USD) -- or I thought I had. Instead, I received a MaiA S2 ($599). Rather than send it back, I reviewed the S2. I’m glad I did -- it was an ear-opener to hear what Pro-Ject has achieved at this price.



Pro-Ject Audio’s MaiA S2 is a half-size component measuring only 8.1”W x 1.5”H x 6.9”D and weighing just 2.04 pounds (not including its outboard power supply). The aluminum case and faceplate feel solid, and come in silver or black. On that faceplate, from left to right, are an on/off button and status LED, a headphone jack, a volume dial, and left and right directional buttons for selecting among the inputs, indicated by a row of LEDs numbered 1 through 9, in five groups: Phono (1), Line (2-4), Digital (5-7), USB (8), and Bluetooth (9).

The MaiA S2 may be small, but sure enough, there on its rear panel were nine sets of input connectors corresponding to those nine LEDs. From left to right, in not quite numerical order and preceded by a ground post for a turntable, are the four analog inputs: Phono (1, RCA); two line-level (2, 3, RCA), and between those a third type (4, 3.5mm). On the digital side are three S/PDIF connections: coaxial (5) and optical (6, 7). Above the opticals is the connector (8) for the Bluetooth antenna (included). Last is a USB Type-B port (9), which accepts audio resolutions up to 24-bit/192kHz (though no DSD) and can be used for connecting a PC or audio streaming device. There’s a jack for the outboard power supply, and at far right are pairs of left and right speaker binding posts. With rear-panel acreage at a premium, these posts are quite close together -- for secure connections, I recommend banana plugs over spade lugs or bare wire. Back on the left side, above and between inputs 1 and 2, is a single 3.5mm analog output jack, useful for connecting a subwoofer or another amplifier. The MaiA S2 includes Bluetooth v.4.0 with aptX compatibility.


Inside the MaiA S2 is a class-D amplifier made in Japan by Flying Mole and specified to output 25Wpc into 8 ohms or 38Wpc into 4 ohms. According to Pro-Ject, this dual-mono amplifier has a tube-like sound. The motorized volume control is analog, rather than the digital attenuators usually found in this price category. The DAC chip is a Cirrus Logic CS4344 and the USB receiver is an XMOS asynchronous type. The MaiA S2’s specified signal/noise ratio is >90dB. The external power supply is a brick that converts your wall plug’s 120V AC to 20V DC.

The MaiA S2 comes with a small, simple remote control whose buttons duplicate the front-panel controls: power on/off, volume up/down, and two to cycle through the inputs. The MaiA S2 is also compatible with Pro-Ject’s bigger IR remote and the Remote Box S2.


Setting up the MaiA S2 was straightforward. The only tricky part was Bluetooth pairing -- when you activate Bluetooth on your smartphone or tablet, the LED on the Bluetooth input should flash, after which you select the correct input on the MaiA S2 or on the remote. What stumped me was that, after pairing the MaiA S2 with my Android smartphone, it wouldn’t pair with my Apple iPad. I tried several times, but no luck. I then realized that I had to first disconnect the smartphone before pairing the MaiA S2 to my iPad -- the Pro-Ject can be paired with only one Bluetooth device at a time. Once I’d figured that out, switching Bluetooth devices was easy.

A few characteristics of the MaiA S2 make it ideal for use in a desktop audio system, which is mostly how I used it. First, it’s small, and occupies very little desk space. Second, its headphone jack makes it easy to switch from listening through speakers to headphones when you don’t want to disturb others around you. Third, being able to connect via USB and Bluetooth makes it easy to switch sources -- for example, you can start by streaming podcasts from your phone via Bluetooth, then switch to streaming music from your computer via USB. I also tried the MaiA S2 as an integrated stereo amp in my main listening room, driving tower speakers or minimonitors, with and without a subwoofer.


When using my smartphone to feed the MaiA S2 wirelessly via Bluetooth, I mostly listened to Spotify. As I worked at my desk each day for hours-long background-listening sessions using this configuration, the amp worked flawlessly, never dropping the Bluetooth signal. For more critical listening, I played 24/192 FLAC files through my smartphone or laptop via a USB link, using foobar2000. My Android phone requires a USB OTG cable to connect to the Pro-Ject’s USB input.

I used the MaiA S2 with a variety of speakers, and felt confident enough in its basic neutrality that I used it to evaluate the audible differences among several minimonitors I was reviewing. With the MaiA S2’s upper-frequency smoothness, I found both Focal’s Dôme Flax and MartinLogan’s Motion 4i speakers great matches. The ML 4i can be especially difficult to match with an amp to sound its best, but the MaiA S2 didn’t exacerbate the speaker’s tendency toward prominent high frequencies. This was evident when I listened to Casey Abrams’s EP Uncovered (24/192 FLAC, Chesky). Giveton Gelin’s trumpet in “What a Wonderful World” can sound a bit harsh through the MartinLogans, but the MaiA S2 produced smooth highs. This shouldn’t be confused with lack of detail -- the MaiA S2 didn’t gloss over details, as was evident when I listened to “Mambo for Roy,” from the Roy Hargrove Big Band’s Emergence (16/44.1 FLAC, Universal). Various players take solos throughout this frenetic track before, toward the end, arranger and pianist Gerald Clayton quiets things down. Hargrove, on trumpet, then leads his band through a crescendo. When he hits his highest notes, I could hear all the detail and dynamic range of his instrument, which helped me feel his emotion -- all courtesy the MaiA S2.


Although I consider aural imaging and soundstaging to be more functions of what a particular pair of speakers can do, through the MaiA S2 both were essentially perfect -- the Pro-Ject never got in the way of the speakers’ ability to produce solid images on a convincing soundstage. For example, in Macy Gray’s jazz interpretation of her hit “I Try,” from her album Stripped (24/192 FLAC, Chesky), her voice was solidly at the center of the soundstage, with Daryl Johns’s double bass on the right and Russell Malone’s electric guitar on the left -- just as they should be. That this album was recorded in the Hirsch Center, Brooklyn, a former church, was evident in the natural reverb I heard through the MaiA S2.

I then moved the Pro-Ject MaiA S2 to my downstairs listening room, where I keep all of my reference audio gear and do my most critical listening, and hooked it up to Focal’s Chora 826-D speakers ($2790/pair). These large towers have a specified sensitivity of 91dB/W/m and nominal impedance of 8 ohms, making them fairly easy to drive. As they sat some 11’ from my listening seat, these 42”H, three-way towers laughably dwarfed the MaiA S2 -- but when I heard the full-range sound this combo produced, I stopped laughing and my jaw dropped. The double bass in Patricia Barber’s jazzy version of the Doors’ “Light My Fire,” on her Modern Cool (16/44.1 FLAC, Premonition/Blue Note), was deep and prominent enough to rattle my blinds. When I played Barber’s performance of her own “Silent Partner” at loud levels, the high frequencies of Dave Douglas’s trumpet remained composed, without getting brittle or edgy. Finally, in Barber’s “Company,” from the same album, the dynamics of the drums were tight and punchy. For even more fun, I connected a Sonus Faber Gravis III subwoofer ($2750) to the MaiA S2’s analog output and experienced even deeper bass and punchier dynamics. This little integrated wasn’t outclassed by far more expensive gear.


I didn’t do much headphone listening through the MaiA S2, but I did spend some time with it and my Harman/Kardon CL headphones. Through this combo, the MaiA S2 provided the same level of transparency that I heard when using it to drive speakers. It might seem counterintuitive to stream from my smartphone to the MaiA S2, then through the latter’s headphone jack to the Harman/Kardons -- why not just connect the headphones directly to the phone? But if I had, I’d have missed the dynamics and punchiness in “Company” provided by the MaiA S2, and which were sorely lacking without it.

Another thing I appreciated about using the MaiA S2 in my main system was its remote control. It has only five buttons, but it sure made the MaiA S2 easy to use from 11’ away. I’ve had other, similarly sized preamp-headphone amps that could be part of an inexpensive, high-quality audio system but that lacked a remote control, and it limited their usefulness.


For a number of years now, my main system has included NuPrime’s IDA-16 integrated amplifier, which outputs 200Wpc into 8 or 4 ohms. Like the Pro-Ject, it has a DAC section with USB input, but lacks Bluetooth connectivity. Although it retails for $2250 compared to the MaiA S2’s $599, and puts out eight times the power, I thought it would be interesting to see what, if anything, all that extra cash and power get you.

Using the Focal Chora 826-D speakers, I was struck by how close the two integrateds sounded. The NuPrime IDA-16 had a bit more control over the lows, most noticeable in the dynamics of “Code Cool,” from Patricia Barber’s Smash (24/192 FLAC, Concord Jazz/HDtracks). The percussion was a bit more explosive through the NuPrime than through the Pro-Ject, and when things got quiet, I heard slightly less noise through the IDA-16. What was important was not how far the MaiA S2 fell short of the IDA-16, but how few shortcomings there were.


Another comparably priced integrated-DAC, and one far more similar to the Pro-Ject MaiA S2, is the SoundStage! Network’s 2019 Product of the Year: NAD’s D 3045 integrated amplifier ($699), with a feature set nearly identical to the MaiA S2’s, but power output of 60Wpc compared to the Pro-Ject’s 25Wpc. I haven’t heard the D 3045, but it might be worth short-listing if you’re in this market.


Pro-Ject Audio Systems’ tiny MaiA S2 integrated amplifier-DAC has a heck of a lot of inputs for its size and all the convenience features you’d want, including Bluetooth connectivity, a remote control, and an output for adding a subwoofer or other amp. It performed reliably in daily use during the six weeks I spent evaluating it.

The most remarkable aspect of the MaiA S2 was its sound. It was a revelation to hear what 25Wpc was able to do with the variety of speakers I drove with it. The MaiA S2 sounded way better than I thought it could -- it punched way above its class. Don’t make the mistake I almost did and laugh it off when you see how tiny it is: This is a seriously high-fidelity integrated-DAC. If you’re in the market for a starter or desktop audio system, or a system for a smaller room, I highly recommend that you give the MaiA S2 a listen.

. . . Vince Hanada

Associated Equipment

  • Integrated amplifier -- NuPrime IDA-16
  • Speakers -- Focal Chora 826-D and Dôme Flax, MartinLogan Motion 4i
  • Subwoofer -- Sonus Faber Gravis III
  • Headphones -- Harman/Kardon CL
  • Sources -- Motorola G4 Android smartphone with foobar2000 app, Lenovo T430 laptop computer, foobar2000
  • Speaker cables -- Analysis Plus Blue Oval
  • Interconnects -- Analysis Plus Super Sub, generic USB OTG link

Pro-Ject MaiA S2 Bluetooth Integrated Amplifier-DAC
Price: $599 USD.
Warranty: Two years parts and labor.

Pro-Ject Audio Systems USA
6655 Wedgwood Road N., Suite 115
Maple Grove, MN 55311-2814
Phone: (510) 843-4500