Disclaimer: KECES S3 was send to us as a review unit in exchange for our honest opinion. We thank team KECES for this opportunity.
My video review:
KECES Audio is proudly making Digital to Analog Converters for more than 10 years already. I still remember researching for affordable DACs at that time and KECES DA-131 and DA-151 would always pop into that list. They were always very serious about power filtering and sonics as they used only high-quality toroidal transformers and musical performing Burr-Brown PCM chips. Time have passed, lessons were learned, technology evolved and that is how KECES S3 came to be. Today I will write about their latest 3-in-1 device that KECES proudly designed and is making in Taiwan and that is S3 - their latest high-performance DAC, Preamp and Headphone amp.
Meet the Family
You might think that nowadays KECES is mostly making linear power supplies and balanced isolation power conditioners like their BP-600 that we reviewed recently but their product portfolio is much wider than that.
KECES is also offering an integrated amplifier, a top-notch phono preamplifier with a separated power supply, a big and imposing 225 Watt per channer power amp and the all in one S3 DAC/ Preamp/ Headphone amp. If you look closely at all their products you will soon realize how much importance KECES is putting into the power filtering as more often than you might think a performance bottleneck will start exactly from there. The need for clean power expanded their portfolio and at this moment they are offering 6 different products that will deliver clean power to your precious audio equipment.
Beauty in Black
Unboxing experience is quite good, it came double boxed. Since the S3 unit is not that heavy, at about 4 Kg there isn’t a ton of foam inside. Nonetheless S3 is well protected from outside world. Inside the package you’ll find the S3 unit, a power cable, a high-quality metal remote, a battery for it, a warranty card and a 15-page user manual.
Design & Build Quality
I think S3 is a beauty in black, the side and front panels are free of any screws, most of the ugly screws are underneath the device so I’m ok with that. The top and front panel have a sculpted CNC-ed KECES logo which I really dig. S3 is a clean looking device and will not draw a lot of attention from our ladies, the WAF (Wife-Acceptance-Factor) is really high, two weeks passed and I was never asked what is this black box on my desk, the ultimate test was passed!
The case is entirely metal made, the body uses a 4mm thickness aluminum sheets, even the remote control is having a thick aluminum construction. The back-plate has 2 open-wide ventilation holes that will dissipate all the heat accumulated inside. S3 is always warm to the touch but never too hot, even in hot summer-days it should not pose a problem stacking with other electronics.
Features & Display settings
The front panel houses a very clever 128-step fully balanced relay-controlled volume pot. This is a very special volume pot, it is very similar to what I’ve seen in Benchmark HPA4 and better than this is probably only the $1400 Alps RK50 pot. The volume pot has three different functions: it will control the volume for the preamp or headphone amp, pushing it once will change the digital or the analog input and a long press will put it or wake it up from the stand-by mode. There is also a gain switch, a pre-out/phones switch and two headphone outputs: a 6.35mm (1/4”) and a 4-pin balanced headphone out that already put a smile on my face. KECES opted for a big and bright OLED screen on the front panel that shows all the important stuff like the selected gain, volume level, input (digital or analog) and the sample rate for PCM and DSD material.
On the back panel you will see a trio of digital inputs: Async USB, Optic and Coaxial, two analog outputs: XLR out and RCA output. There is also two XLR and RCA inputs meaning S3 can be used a dedicated Pre-amp for your speaker-based system or as a dedicated headphone amp in case you want to use another DAC but I doubt that will be the case with it, more about that in a minute. The power of the analog outputs can be controlled of course, RCA out goes up to 2V and XLR out goes up to 4V at unity gain of 0dB.
As you can see, S3 can be a dedicated DAC, Preamp, Headphone amp or a combination of two in a single beautiful black case.
Using the remote it is super easy controlling the unit as you can wake it up or put in stand-by mode, select the desired input or change the volume setting, muting it is also an option.
Under the Hood of S3
S3 looks incredibly clean and very well put together. Notice the high-quality toroidal power transformer inside, audio grade capacitors, an ultra-short path between the input connectors and input gain op-amps, lots of high-quality relays for a precise volume matching done in the analog domain without losing precious bits of resolution.
S3 is rocking the latest ESS Sabre family of DAC chips, it is using the desktop class 8 channel ES 9026 PRO chip. It wouldn’t be a KECES device if would not have an isolation circuit inside that completely separates the grounding of the digital and analog sections. In terms of power filtering this is as good as it can get.
The headphone amp section can offer up to 2 Watts of power into 32 Ohms on the balanced out and about 1.2 Watts on the SE output, that is plenty even for harder to drive headphones. Luckily, I do have 3 pairs of hard to drive headphones and will put S3 thought some heavy testing. I can tell you in advance that both headphone outs were not put there for convenience as S3 can be used as a powerful stand-alone headphone amp and my listening tests proved that.
S3 will consume up to 30 Watts, for a DAC, preamp and headphone amp unit that is quite a lot. My feature packed Matrix Audio Element X consumes less that 25W and X-Sabre Pro uses less than 10W. S3 is already showing me patterns and signs of how it might sound.
S3 is moderately big and weighs about 4 Kg, it is super easy using it as an all-in-one unit, in a stereo system please don’t place it on top of your power amp for a better heat dissipation.
The best digital input is of course USB as it can decode up to 32bit/384kHz of PCM and DSD up to DSD256, optical and coaxial inputs will decode up to 24bit/192 kHz and just DSD64 (via DoP).
I. In a headphone-based system
A. Using S3 with sensitive IEMs
I was already leaving small hints like the 30W power consumption (much higher than typical DAC and headphone amp units are having), big toroidal transformer inside, an isolation circuit that completely separates the grounding of the digital and analog sections, a dedicated balanced headphone amp and a very advanced relay-controlled volume pot. All of those already hinted at very good performance but I wasn’t prepared for the performance that followed in my listening tests.
I plugged on the 6.35mm jack my very sensitive FiiO FA7 and IKKO OH1 IEMs, I selected low gain, put my music on pause and almost maxed the volume and was impressed to find a black silence and a clean background even with a pair of super-sensitive IEMs. In terms of how clean its internal headphone amp section is you need to know that it easily outperformed the Mytek Brooklyn DAC+, my reference Headamp Gilmore Lite Mk2, the Burson Playmate and the Erzetich Bacillus. In terms of cleanness it is on the same level with Aune S6 PRO and S7 PRO and just barely under the top-performing Benchmark HPA4.
Unplugging both balanced power conditioners from the acoustic chain resulted in a higher noise floor to a point where I can hear it with IEMs, that was unexpected. I will be changing my final ratings right now.
I call it already impressively clean, free of any nasty gremlins, having a black background that will please headphone enthusiasts. Both headphone outputs have a super low-Z 0.6 Ohm output impedance so any IEM, earphone or headphone you will plug-in the diaphragm will have absolute control and grip, to me S3 sounded as the most effortless All-in-one unit I tested at my place. Combine a super low output impedance with a very low total harmonic distortion and with a powerful headphone amp section and you can probably guess how S3 might sound.
I listened to some old folk-rock and was curious if I will hear any coloration of the internal headphone amp and frankly its sound reminded me a lot about the Benchmark HPA4 with its linear and colorless performance. To me KECES S3 sounds linear without putting an emphasis on any particular frequency range. What really stood-out is how strongly it punched and kicked those headphone drivers, very effortless sounding. It pumped a lot of engagement and joy into my IEMs as they sounded livelier, faster and kicked much harder compared to a portable device.
All that raw power, speed of delivery and control will be completely wasted if there wasn’t a hint of finesse and refinement, that is why I decided to listen to some Enigma – Sadness followed by Principles Of Lust. The smoother and musical character of both songs was perfectly rendered by S3, all those small bells firing on left and right, those angelic voices and the super controlled bass created a complete relaxation of body and mind. That is right, when needed S3 can sound refined and smooth and when thunder is being called for, it will be unleashed with an incredible slam and kick.
In terms of IEM and earphone listening there is nothing wrong and I sincerely can’t see any real faults of this unit. This engaging sound signature reminds me that without a high dynamic range all this will not be possible, so in terms of dynamics S3 is very good and goes shoulder to shoulder with high-performance desktop headphone amps.
B. Using S3 with hard to drive headphones on the balanced and SE output.
Here are some fun facts: Hifiman Arya that I reviewed recently is a hard to drive planar-magnetic headphone, at only 90 db per 1mW it is the hardest to drive one from my table. Yet, at just 70 volume (out of 128 steps) at high gain Arya and my ears could barely hold more volume, just for few moments I tried going up to 80 volume and went immediately back to preserve my hearing. KECES S3 has some very serious power under its belt!
Later on, I decided to use the closed-back Sennheiser HD820 on the same 4-pin balanced out and I could go maximum to 65 volume, with my Quad ERA-1 I could go maximum to ~63 and maximum to ~60 with the Sennheiser HD660S. So, in the worst-case scenario I had another 48 dB of headroom left of the volume pot, that is not mighty good, that is God-level good! Before pushing that play button please select carefully your volume setting and don’t forget IEMs need much less power than that.
I can’t imagine what headphone will be needed to reach 100 volume, yet alone maximum 128 volume setting? Power overwhelming? Yes, for sure.
Even now I can answer your Audeze LCD-4, Hifiman HE6/HE-SE, Susvara or Abyss AB-1266 burning questions. Yes, it will drive any of those with authority, control and cojones.
If you look carefully around here you will observe that I really like listening to DAC+ headphone amp units, I will not hide the ugly truth, this is one of my biggest audiophile fetishes. I love testing and listening to DAC/Headphone amp units, I tested a lot of them lately. Out of all of them (including Matrix Element X and Mytek Brooklyn DAC+) this Keces S3 has the best headphone amp section by a long shot.
When I listened to Brooklyn DAC+ and to Matrix Element X I knew they both shared an excellent DAC section, but I also knew they both had just decent, mid to high-class performance headphone amp sections, on those units I craved going balanced to a another dedicated headphone amp unit. However, with Keces S3, I don’t have the same feeling as S3 is offering ultimate drive control, speed, slam and a big open-wide soundstage. S3 doesn’t need a separate desktop headphone amp to shine at its best.
Listening to Virgin Black – Our Wings are Burning was a revelatory experience as it shown me that it can be gentle, refined but also brutal, aggressive, biting and hard hitting. This particular track combines all of those and can be a weird experience at first. This song carries impressive dynamics, there are many low and high intensity sounds that will put into a relaxed or tense state, a head-bang inducing song for sure.
I want to outline and reinforce that S3 is very effortless sounding, it has an impressive control over the headphone drivers, it sounds impressively fast and carries a hard-hitting slam when called for and even listening to harder to drive dynamic or planar-magnetic headphones was an eye-opening experience for me. If you consider yourself a headphone enthusiast and don’t want to have separate DAC and headphone amp units, I think Keces S3 performs admirable and up there with the best I’ve tried.
There wasn’t an instance where I would doubt the S3 performance when it comes to headphone pairings. Its internal headphone amp and this DAC/Amp unit in general doesn’t have a coloration and sounds linear/neutral, you will basically be listening to the limits of your IEMs, earphones or headphones and nothing more.
In terms of subjective headphone pairings, I would stay away from aggressive and U-shaped sounding headphones since S3 can put an emphasis on all those minuses with its revealing nature.
II. In a speaker-based system
My active KEF LS50W loudspeakers are having an internal Hi-Res DAC but offer the possibility of using an external DAC and this is exactly what I did.
I will first try to answer the technical specs snobs that feel that only TOTL DAC chips will sound the best no matter the implementation used. The ES 9026 PRO inside the S3 sounded much better than the ES 9038 implementation of Burson Swing and about on the same level with ES 9028 of Mytek Brooklyn DAC+ and Benchmark DAC3L that I tested not a long time ago. DAC chips tell only 20% of the story and the rest is much more important.
I am hearing a big family resembles here as S3 is sounding very similar to those units but borrows a little bit of naturalness and boldness found in Matrix Audio X-Sabre Pro and Element X units. Going deeper and listening more and more music I tend to believe KECES did the right thing going with a big isolation toroidal power transformer inside as It sounds so holographic and effortless on speakers as well as it was on headphones.
There were already many times when the internal DAC of KEF LS50W was outperformed, mainly in terms of holography and wide soundstage. This time, with KECES I am hearing an incredible grip, an impressive start and stop of the speaker diaphragm. I think in terms of transient response S3 is playing in big boy category and elegantly outperformed the Benchmark DAC3L and the Mytek Brooklyn DAC+. Compared to those two units, it doesn’t just sound as fast, but it also slams harder and carries a little bit more air with every beat, in this regard it reminds me a lot about Matrix Element X that has the same effortless and hard-hitting nature.
The bass slam is so outlined and steps forward so many times that I thought it boosted the bass performance a bit, but that is not the case because it doesn’t go lower, it just hits my eardrums harder – a very pleasing effect on rock and electronica music.
S3 is among the hardest hitting DAC units I had the pleasure of listening at my place, it is so engaging it is almost illegal sounding as fun and head-banging.
In terms of frequency response from the lowest bass to the highest treble KECES S3 sounded linear as a ruler, always hyper-detailed with a focused pin-point imaging, yet involving, musical and so incredibly engaging and fun.
I have tested a lot of All-in-one units based on the latest ESS Sabre chipsets, still only very few of them sounded really fun and as engaging as this unit. I started tracing all those units, I re-read my reviews trying to understand from where this fun-factor is coming from. The only conclusion I can draw is that high-quality power filtering is doing all this magic. Take for example DAC3 L, Brooklyn DAC+ and Burson Swing – all of them are relying on switching power supplies and when I connected all of them to the KECES BP-600 Isolation Power Conditioner all of those basically transformed into hard-hitting monsters. In their stock form they sounded fine but lean and not as engaging in the long term. On the opposite side of things Matrix X-Sabre Pro and Element X are relying on top-quality Noratel toroidal transformers and those two are sounding as engaging and fun as the Keces S3. If you are a DAC or DAC/headphone amp combo manufacturer then please, for the love of music, throw away those switching power supplies and start using higher grade toroidal transformers. Why? They sound better, much better.
I think I have found my love, my drinking buddy, my metal brother, my music companion (you get me) in terms All-in-one units. KECES S3 might not offer the widest of possibilities and features, but it sounds so engaging, so effortless and kicks so hard. It is like taking an audiophile beating. Love it from the bottom of my darkened heart!
KECES S3 (1400 USD) VS Matrix Audio Element X (3000 USD)
Since for my subjective preference it already outperformed the Benchmark DAC3L and Mytek Brooklyn DAC+, I decided to compare it to my fresh bought Matrix Element X.
As you probably guessed Element X has many more features, like an internal streamer, an internal player, MQA decoding, DLNA and Roon support (Soon!), it also can be controlled via the MA app, so in terms of versatility Element X is in a game of its own, can’t be beaten.
In terms of plain delight and music listening as a DAC + headphone amp unit this might amaze you but KECES S3 had way more power, control, grip and overall enjoyment level. I wish my Element X would have the same headphone amp section of S3. There isn’t a single doubt in my mind that in terms of headphone listening S3 can power any set of headphones, Element X by comparison can’t do that and struggles with Hifiman Arya at delivering this holographic, effortless and super dynamic performance. As a combo unit, I think Keces S3 is playing on a very high level where not a lot of units can compete with it. Sure, it loses just a tiny bit of detail retrieval and layering compared to the best I’ve tried but that is understandable, given the price point S3 is having.
As a DAC unit alone, the game changes a bit. Using both on the USB input from a PC, Element X will sound a bit more focused, will offer a better detail retrieval and a wider soundstage. The difference is not that big but a noticeable one.
Now, if I move to the internal player of Element X completely bypassing the Windows OS then the performance of Element X plunges forward even more. You should understand that Element X was designed being used as a streamer and as a DAC, the headphone amp section was put there mostly for convenience.
KECES S3 didn’t bottleneck its preamp, headphone amp or DAC section and I would personally use it in front of a PC with some top quality headphones or in a speaker based system as well, don’t forget it has a top quality relay-based volume control and a remote, add a power amp and some nice speakers and you are good to go.
When KECES S3 arrived at my door I knew it had great potential mainly because of its high-performance volume control and power filtering, but I was not prepared for this kind of audio performance, especially at this price point.
As a DAC and headphone amp combo, it plays in a game of its own since there aren’t a lot of units that I am aware of playing in the same ballpark. Want to use it from portable headphones to hard to drive headphones? Be my guest, S3 will do that with gobs of power to spare.
Want to use it with a power amp controlling your passive speakers or directly with a pair of active speakers? Sure, why not? With its remote and perfectly matched volume control it can’t be more convenient that this.
S3 possesses such a fast, punchy and engaging sound signature that it should be banned. You know when I think about it - all DACs that I am aware of can sound slow, smooth and easy going with the right music, but only very few of them can sound as fast, engaging and fun as S3.
KECES S3 can be purchased for $1400 in USA and for €1500 here in Europe, contact your local distributor right here.
- Solid build quality with an impressive simple design
- A feature-packed 3-in-1 device
- Sounds neutral, layered and extended, lacks a sound coloration
- A high resolution and transparency level
- Sounds wide and very well spread around the listener
- Very precise pin-point imaging
- Among the best pace, rhythm and timing with fast kicking dynamics I had the pleasure of hearing
- Linear and uncolored headphone amp section with power to spare
- Lacks any noise or distortion
- Wide selection of digital inputs and analog outputs
- Background noise with IEMs, could be lowered with a balanced power conditioner.
- DACs: KECES S3, Matrix Audio Element X, Matrix Audio X-Sabre Pro, Mytek Brooklyn DAC+, Aune S6 PRO, Burson Swing & Playmate
- Headphone amps: Benchmark HPA4, Aune S7 PRO, Erzetich Bacillus, Headamp Gilmore Like Mk2
- IEMs: FiiO FA7, IKKO OH1
- Full-sized headphones: Sennheiser HD820, Sennheiser HD660S, Hifiman Arya, Quad ERA-1, OLLO Audio S4
- Loudspeakers: KEF LS50W
- Interconnects: QED Reference XLR, Aune AL3 XLR
- Power Cables: Isotek EVO3 Premier
- Balanced Power Conditioners: KECES BP-600, PLiXiR Elite BAC400