DISCLAIMER: Lotoo provided me with the PAW S1 in return for my honest opinion. I am not personally affiliated with the company in any way, nor do I receive any monetary rewards for a positive evaluation. I’d like to thank Lotoo for their kindness and support. The review is as follows.

The past couple cycles have seen Lotoo go from strength from strength. The release of their PAW Gold Touch player saw them gain acclaim at the top flight. Then, the subsequent release of their more affordable PAW 6000 did the same in the mid-tier market. Much of that praise was attributed to their sleek, modernised aesthetic, impeccable build quality and all the proprietary software they packed in there too. Now, bringing all this and entry-level pricing into the mobile market is Lotoo’s PAW S1 USB DAC/amp. A balanced output, OLED display and Lotoo OS in hand, the PAW S1 is the dongle to beat.

Lotoo PAW S1

  • DAC chip: AKM AK4377
  • Available inputs: USB Type-C, Lightning (sold separately)
  • Available outputs: 4.4mm balanced jack, 3.5mm single-ended jack
  • Sample rate support: Up to PCM 32-bit/384kHz, DSD64 and DSD128
  • Output power: 70mW/ch @ 32Ω (single-ended), 120mW/ch @ 32Ω (balanced)
  • Key feature(s) (if any): OLED display, EFX sound-shaping, MQA decoding, LTOS
  • Price: $165
  • Website: www.lotoo.cn

Packaging and Build

This PAW S1 comes in a clean, compact package, adorned all around with sleek, matte-finished artwork. Also, on the top-left corner is a sticker from Pentaconn, which indicates that the 4.4mm socket Lotoo have sourced for this DAC/amp is of utmost quality. Inside is the S1 itself sat within a foam cutout. And, underneath that is a quick-start guide and a warranty card, along with the S1’s accessories also sat in foam. This consists of a short Type-C-to-Type-C cable to connect the S1 to Type-C devices. And, there’s a USB 3.0 adapter for, say, laptops and desktops too; all in Lotoo’s sleek, anodised aesthetic.

With this S1, Lotoo prove that – no matter the price tier – build quality is something they know how to deliver. Its chassis is excellently compact, yet impressive in robustness and heft. It’s by no means as luxurious-feeling as their bigger, pricier DAPs. But, given the price and size of the S1, you’d be hard-pressed to find a dongle that looks and feels as premium. It’s a near-unibody design with a screwed-on bottom panel. Despite how flush it sits against the rest of the chassis, I do wish Lotoo had put screws on all four corners, rather than just two. The end with screws feels solid and firm as I tap my finger on it, while the opposite feels ever-so-slightly loose. Again, it still sits flush against the rest of the device. But, it does take away a teeny bit from the S1’s near-flawless feel. That aside, however, Lotoo have, again, finished their product superbly; dressed in an even and seamless coat of anodised-black, then capped with sharply-defined engravings above and below.

We then get to the one of this device’s defining features: The 128×32 OLED display. The screen in its default state feature the current track’s sample rate, the S1’s gain mode (Low or High) and the current volume level on the upper third. Taking up the rest of this screen is the EFX profile you’ve selected, which essentially is Lotoo’s DSP or sound-shaping. Personally, I like how the S1’s UI looks. It’s clean, it isn’t too flashy and it tells you all you need to know. And, it’s lit up sufficiently with zero traces of backlight bleed too. Lastly, as a finishing touch, Lotoo have also incorporated some sliding animations that appear when you cycle through EFX profiles and gain modes, which gives the UI some life and adds that last bit of polish.

Bookending the S1’s body is the device’s I/O, which have similarly been installed seamlessly. The USB-C jack sits perfectly against its opening with zero crookedness or gaps, and the same goes for both the 3.5mm and 4.4mm sockets. There’s a touch more tightness to those audio outputs than ones I’d find on my laptop or DAP, but it shouldn’t be much of a worry. Lastly, the S1’s three buttons sit perfectly level and still, are engraved precisely and depress with a very firm, tactile click.

Ergonomics and Physical Controls

Clearly, given the S1’s compact, lightweight design, it’s an absolute breeze to carry around; whether in an in-ear pouch or your coat pocket, even. It isn’t as thin as some of Cozoy’s USB dongles, for example, but I reckon it’ll still make an easy fit in whatever space you’re carrying your other electronics in. That’s further aided by its detachable cable system. Speaking of, Lotoo’s included braided cables have good heft to them as well, so I won’t have to worry about those wires potentially snapping off if I hang this S1 off a table edge, or bending and kinking if I stuff the dongle in a trouser pocket. Overall, this is a DAC that’s as easy to carry as it is to keep, and built tough enough to withstand the hustle of daily, portable listening.

The PAW S1’s physical controls consist of three buttons, whose base functions are Function, Volume Up and Volume Down. Pressing the first brings up the EFX selection screen, where you can use the Volume buttons to cycle through this device’s 16 included EQ profiles. Pressing that Function button again will summon the gain selection screen, where you can either select High Gain or Low Gain. For example, for headphones and in-ears, respectively. Overall, it’s an easy, intuitive system that’s also quick, due to the dongle’s responsiveness. If I could make one suggestion, Lotoo could add a way to revert the EFX profile back to Stock in a single action. Perhaps, by pressing both Volume buttons at once. But, that is my only qualm.

Connectivity

This PAW S1 is capable of outputting both 4.4mm balanced and 3.5mm single-ended audio, though, obviously, not at the same time. Still, this addition of a TRRRS socket does put it a step above most USB dongles available today; a Pentaconn-issued one, no less. Volume on both outputs have a range of 100 steps, which should be beyond sufficient fine-tuning for most users. Then, for the input, you have the S1’s modular Type-C connector. By default, it connects to a Type-C-to-Type-C cable with, again, an optional USB 3.0 adapter. And, you could also purchase Lotoo’s Lightning cable attachment to use the S1 with Apple’s mobile devices. It features the same braiding and hardware as the default cable; a detail I love to see.

I’ve tested this PAW S1 with a couple other Type-C cables, and those results are a tad hit-or-miss. The ultra-long charging cable that I use with my MacBook does get this device to work, but it disconnects intermittently; presumably, because of a lack of power. The USB 3.0 to Type-C cable that comes with the PAW Gold Touch works perfectly fine. So, I’d personally recommend using the cables Lotoo provides for the best results. Though, in a pinch, most standard cables can work too.

Sound Impressions

Lotoo’s PAW S1 sports a balanced, natural sound with no glaring colourations. It limits itself to mild bends every now and again, which include a light taper in the upper registers and a more open, transparent midrange. But, that aside, the S1’s tonality remains relatively linear, which gives it great versatility and easy matching. Structurally, the notes it outputs have good size and weight to them; full-sounding and substantial at all times. Yet, again, that is achieved without elevating the mid-bass or low-mids, so you won’t get any excess warmth permeating – mucking up – the stage. What this size adds is a more involving sense of presence and musicality, especially with band arrangements like The W.I.M. Trio’s Volume 1 LP. It also contributes an alluring intimacy with vocalists like Diana Krall, while, again, keeping it all organised across the board.

Spatially, the S1 lies certainly on the more intimate side. The image it puts out isn’t the most out-of-head, neither is it the most holographic. On Empire Ears’ ODIN, I find the stage to have the slightest bit more depth than width, but it’s a pretty small difference, so you’re not gonna get audio that feels mono or anything like that. Aiding that intimate stage, however, is excellent precision and control when it comes to the device’s imaging. Instruments, despite their added midrange heft, sport clean edges with channels of air running between. And, they’re positioned with a palpable spread as well. So, even with the limited real estate, Lotoo have proven themselves capable of finesse in any form. Finally, we have the S1’s black background. It isn’t necessarily as crisp as some of the portable DAPs I’ve heard, so don’t expect those levels of dynamics out of the S1. But, at this price tier and form factor, it’s clearly among the best I’ve heard, especially down in the low-end.

Down low, the S1 comes across linear, transparent and clear; neither boisterously boosted nor overly tight. It limits itself to operating within the centre of the space, which is part of the reason for the crisp, clean backdrop. But, it still imparts a decent amount of oomph and gusto too. That’s probably less ideal if you’re searching for a big, bountiful bottom-end. So, those after a cleaner, airier, more technical bottom will find more to love in the S1. Technically, it’s a quick, well-extended bass that never gets in the way of the mids. Bassheads may find it polite when it comes to skull-rattling bass lines. But, at the same time, it imparts just enough wetness to have character, especially on the kick drum. The rapid, single-pedal hits on Larnell Lewis’s Change Your Mind (RTM), for example, still have superb body, so this lick doesn’t end up anaemic or flat.

Towards its midrange, the S1 has the tiniest lift towards 2-3kHz, which inches vocals forward and imbues them with a tad more presence than strictly neutral. Though, it never pushes quite enough to become strictly vocal-focused, which I think benefits the S1’s versatility. You won’t get buttery vocals on one track, then have to sit through boxy, saturated drums on the next. It simply adds that touch of oomph, which, again, is a great showcase of this device’s finesse. As mentioned, the S1 sports nicely-structured notes that have richness and heft without having to elevate the lows or low-mids. Separation, as a result, is clean, and the S1 layers precisely as well. Those reeds on Snarky Puppy’s Shofukan, for example, though not distantly spaced out, are distinctly identifiable. The same goes for the strings on The Curtain. Again, it simply lacks a touch of dynamics to me. Leads don’t jump out and arrest you quite like they do on higher-end DAPs or amps. But, once again, for the form factor and price, you’d be hard-pressed to find mids that balance weight and finesse like this S1 easily does.

And, up top, the S1 showcases lots of air and extension, but without overdoing quantity. It’s a slightly softer, more subtle-sounding treble, which hands a less aggressive touch to cymbals and rides. If your in-ear or track has a tendency of tizz-y hi-hats, for example, the dongle will curb them nicely. But, again, it does so without becoming rolled-off or muffled. Air is plenty on this S1, and it avoids bottlenecking e-stat-equipped IEMs like Vision Ears’ hybrid ELYSIUM. Cymbals, though not as bright or forwardly as they can be on more clarity-oriented sources, are still resolved down to the tail and surrounded by its crisp, stable backdrop. Timbre-wise, the S1’s low-treble notes resemble those of Lotoo’s PAW Gold Touch; light and tight, such that glares and tizzes never linger. Then, higher up, again, the S1 sports crisp, open, yet reserved air in spades.

Balanced vs. Single-Ended

Between the S1’s single-ended and balanced outputs, Lotoo – like on their PAW Gold Touch – manages to maintain fairly consistent tonalities. To my ears, its balanced output is about 3-5 steps louder on the Vision Ears ELYSIUM. Then, it dons a few technical advantages over the single-ended socket too. Stereo spread feels a bit wider to me. Hard-panned sounds like the ride bell or stack cymbal on Larnell Lewis’s Change Your Mind (RTM) have a tad more tactility, solidity and attack to them. Then, the centre-image feels a touch deeper as well, though I’m not sure whether or not that’s a by-product of this balanced output’s stronger extremes. In any case, whichever one you use, you’ll be guaranteed the same, refined sound.

Tone Shaping

The S1, again, incorporates Lotoo’s slew of EQ and DSP. The 16 filters featured on this device spans from timbre-shaping to image manipulation, and you can get do a fair amount to the in-ear or headphone you’ve got. I enjoy the Sweet setting with Empire Ears’ ODIN, for example. Though, it should be noted that these settings aren’t exactly subtle changes. These are fairly strong filters; perhaps, a bit too strong if what you’re looking for is a little nudge here or there. But, it’s an extra feature nonetheless, and one that Lotoo can further expand on with firmware updates. Speaking of firmware, Lotoo just added MQA decoding to the S1 through its latest update; so you can now listen to hi-res material from, say, TIDAL too.

Noise Floor and Power

When determining a source’s noise floor, my reference has always been the Empire Ears Phantom; a hiss hound on most of the gear I’ve tried it with. And, just like their PAW Gold Touch before it, the S1 passes the noise test with flying colours. Hiss is practically inaudible; only heard when the track literally isn’t playing. And, this is true on both its low and high gain settings. When plugged into my MacBook Pro, though, the Phantom does pick up a tiny bit of RF noise, which sounds like tiny ticks every now and again. Oddly, it’s never an issue when I pair the S1 with my iPhone 11 Pro. Regardless, the S1 is a dead-quiet dongle 99% of the time, and it’s the perfect accompaniment to any sensitive in-ear monitor on your rotation.

On the opposite end of the spectrum is Vision Ears’ electrostat-equipped, hybrid ELYSIUM. Renowned for its potential to scale with power, the S1 fares decently with it. It achieves that tactile quality to the treble, which indicates to me that the tweeters have been fed well. It doesn’t do so to the extent of the PAW Gold Touch, or some of the desktop amps I tested with it. But, it still puts up a good showing, and I think most ELYSIUM owners will find the S1 a suitable portable solution. 

Volume-wise, on a modernly-mastered track, this S1 achieves what I’d consider a good listening volume on the ELYSIUM at 50 out of 100 steps. The Phantom, by contrast, requires no more than 20. Because of that, the S1, to me, has the best of both worlds. Whether the IEM’s sensitive or demanding, this S1 delivers a clean, quiet and dynamic signal every time.

Select Comparisons

Cozoy TAKT C ($115)

Comparing the S1 against Cozoy’s TAKT C, it’s clear that the former has quite a bit more precision up its sleeve. This S1 is cleaner-sounding with an audibly blacker background, tighter, more precise imaging and crisper, more tightly-separated layers. Then, the S1’s stereo spread is considerably wider too. These differences are all observable on a mix like DeAndre Brackensick’s Shoulda Known Better. This blacker backdrop and precise positioning heightens the space between the lead vocals and the percussion sparsely spread throughout the soundscape, which raises holography. Then, it also makes the little shakers feel substantial and tactile on their own. Add to that a wider space, and you’ll have that surround sound feel.

Tonally, the TAKT-C has a slightly more aggressive tonality, due to its low-treble lift. It’s got a brighter bite around 5-6kHz, while the S1 chooses to have a gentler touch. With inherently brighter in-ears like the ELYSIUM, the S1’s naturalness gifts the pairing a more linear or natural sound. Whereas, the opposite may be true on a naturally-warm IEM. The rest of their frequency ranges are largely similar. Though, the S1 does have a tad more sub-bass extension, which lends it the edge in low-end physicality, despite their similar quantities. But, otherwise, the differences between these two devices are mostly technical in nature. And, here, this S1’s price premium does paint an accurate picture; the stronger performer of the two.

Verdict

The Lotoo PAW S1 is unquestionably the most well-built, feature-packed and versatile USB source I’ve seen yet. It bleeds the company’s precision and ingenuity, from its CNC’d, aluminium-alloy body, to its dual-output design. Then, comes the innovation of its OLED display and EQ functionality. And, topping it off is the balanced, bodied sound Lotoo have instilled with precise imaging and separation as well. Now, it probably won’t topple over those $1000 audio players anytime soon, especially when it comes to stage expansion or riveting, sweeping dynamics. And, it’s a tad pricier than the typical dongle too. Nevertheless, to me, there’s just no questioning how solid, versatile and near-future-proof this S1 is. It’s yet another win in Lotoo’s record books, and, as far as I (and quite a few others) are concerned, it’s absolutely the USB source to beat.