It was back in August 2020 when Cayin released the N3Pro, the world's first digital audio player (DAP) with a pair of NOS vacuum tubes JAN6418 produced by Raytheon, and it was an affordable one. The saga continues, three and a half years later, with the N3Ultra, an upgraded version of the N3Pro, a DAP which still offers triple timbres (solid state and dual tube) at a very reasonable price. The N3Ultra is Cayin’s most affordable player and the most cost effective way to enjoy tube sound at a DAP.
Technical stuff
Cayin has equipped the N3 Ultra with two Raytheon JAN6418 military-grade miniature direct-heated pentode NOS vacuum tubes. The device has three user switchable modes, Classic Tube, Modern Tube, and Solid-State. Unlike the N3Pro, all outputs of the N3Ultra, including the 4.4mm balanced, 3.5mm single-ended, and line outputs, each have support for both vacuum tube and solid-state timbres. The tubes are carefully placed in their in-house developed shock-absorbing frame. They also have a suspension effect for complete protection and minimum microphonic noise.
The Cayin N3Ultra is equipped with two AKM 4493S DAC chips in mono mode configuration for fully differential output and a JRC NJW1195A analog volume controller. These 32-bit DAC chips are placed in mono mode, one for each channel. Independent DAC chips with properly designed amp sections minimizes crosstalk and enhances the output with enhanced dynamic range and low distortion. It supports high-resolution 32-bit/768kHz PCM signals and native DSD512 audio signals.
The N3Ultra provides a maximum output power of 600mW on the balanced 4.4mm headphone output. Additionally, whereas the tube output power on the N3Pro was nearly half that of the solid-state output, the N3Ultra maintains equal output power for both tube and transistor timbres. The JAN6418 is a single-channel tube, with one tube handling only one audio channel so strictly speaking, the 4.4mm balanced headphone and line output are balanced driven, but this is not a fully balanced circuit from DAC to LPF to amplification. Conversely, the transistor timbre maintains a fully balanced process throughout.
You can read everything about the Cayin N3Ultra
here.
No wireless features for a reason
The JAN6418, or traditional vacuum tube products (as opposed to the KORG Nutube 6P1), have very weak resistance to interference from wireless signals. When the tubes are close to antennas or wireless devices, users may hear a noise like a "sizzling" sound through the headphones, which severely affects the audio experience, turning the carefully designed tube sound into a potential flaw.
The N3Pro featured OTA wireless updating and bidirectional Bluetooth/Wi-Fi music transfer functions, necessitating internal antennas. Many users reported noise when listening to music when they selected vacuum tube timbre, and the problem was typically resolved by instructing them to turn off the wireless function.
Therefore, Cayin has decided to get rid of the antenna with the N3Ultra, this implies both Bluetooth and WiFi features, like online streaming are not supported. Cayin has primarily focused on the application and design related to the vacuum tube audio, which is a significant aspect of the N3Ultra.
So, this is a DAP without WiFi antenna and people who don't do local file playback, must connect it to a PC or a smartphone in order to access their favorite streaming services. I have also abandoned file playback a long time ago, so I prefer to think of the Cayin N3Ultra as a portable, battery powered, USB DAC rather than a DAP. I just connect it to a dedicated streamer or a laptop and enjoy my music with the N3Ultra.
Non Audio stuff
The rectangularly shaped Cayin N3Ultra is made from sand blasted, CNC machined aluminum with a smooth black finish. The design is rather common and a bit conservative but I like the golden color of the buttons and the volume wheel. The back panel is reinforced with glass and the edges of the chassis are mildly rounded to make it sit comfortably at your palm. Build quality and finish are truly exceptional.
The main design elements of the N3Ultra are the two laser drilled, side mounted tube windows at the left side of the chassis. These are not actually the tubes glowing themselves but two LEDs that were added on purpose to give this warm glowing effect that is visually appealing, especially under low light conditions. Tubes or LEDs, I don't care as long as the effect is stunning and beautiful looking.
Weighing just 240g and measuring 125x65.5x19.5mn, the Cayin N3Ultra is slightly bigger than N3Pro but still very compact and lightweight , thus suitable for one-hand use and everyday carry. It is more portable than several other DAPs that don't have tubes inside.
Hardware and software
As of writing this review, the Cayin N3Ultra was updated to the latest v1.3 firmware. Firmware updates can only be performed through the SD card.
Cayin N3 Ultra is a puristic DAP that utilizes Android 8.1 as its underlying operating system with extensive optimizations to maintain the advantages of Android in touch display and charging management. However this is a closed, pure audio system design for its UI, offering a clean and straightforward user interface. This closed system dedicates the hardware solely to music playback. It lacks internal storage but supports external TF cards and bidirectional USB DAC functionality, as well as coaxial SPDIF output embedded in the USB-C connector (a special adapter is needed for this function). This DAP doesn't support any other functions except for local music playback through the TF card or OTG storage and USB DAC function. A handy feature is that the N3Ultra will scan both the SD card and an external OTG drive and integrate their content in the same music library.
The processor is the Qualcomm 425 with 2GB of RAM and the N3Ultra features a 4.1” HD 720x1280 TFT-LCD screen, which is not that vibrant but offers a smooth touch operation and supports double tap to wake. The platform is fast and responsive, large capacity SD cards get scanned fast and access to libraries is user friendly and lag free. You can use folders or tags browsing and cover art is displayed during playback. A global search function for album, artist, and music genre contents in the scanned music library is also supported. The hardware and the Android version might be a little underwhelming but given the closed OS platform, it is not actually a problem as you are not going to install any third party applications.
Use experience
The N3Ultra is highly customizable and the user can set various audio parameters like PCM and DSD filters, gain, line out level, DSD gain compensation, channel Balance, max volume limit etc. All regular Android system settings, like display, font size, configure lock screen buttons etc, are also supported. The main screen has all the useful menu shortcuts and the drop down bar allows fast access to various functions like timbre selection and gain. Navigation is fast , smooth and user friendly while the system supports gesture controls.
The N3Ultra has a volume control wheel that has a click feedback and is smooth to operate plus three buttons for playback control. The TF card is located at the left side and the headphone outputs at the bottom, together with the USB type-C port. The 3.5mm headphone and line outputs are dedicated while the 4.4mm is shared on the same jack. A touch button at the bottom center of the front panel serves as home and back button for various operations. It will also glow in a different color according to the input sampling rate, a feature that can be disabled from the menu.
The Parametric Equalizer
A special feature of the Cayin N3Ultra is the user configurable, 10 bands parametric EQ that allows for a detailed sound customization according to listening preferences. A classic 10 bands graphic equalizer is also available and both EQ modes are also effective during USB DAC input but you must remember to enable it before establishing the USB connection. I don't use an equalizer for music listening so I cannot offer further insight.
USB input/output
The N3Ultra supports bidirectional USB connection so it can be used both as a USB DAC decoder and a digital transport to an external DAC. You can also use a special USB type-C to optical SPDIF adapter if it is needed. USB DAC audio performance is flawless and of the highest quality, it was my main input method while evaluating the device. The only thing of notice is that during this mode, the drop down menu is not working and in order to access various audio adjustments you have to press the little settings icon at the upper right corner of the screen.
A very handy feature of the USB DAC function is that you can configure the device to charge or not at the same time. Thus you can connect it to a smartphone without depleting its battery or otherwise connect to a PC and enable charge and play at the same time.
Battery duration
The Cayin N3Ultra is equipped with a 4500mAh battery that supports fast charging and has a carefully tuned power management system. You can get the battery from 20% to 80% in about an hour. Battery duration is very satisfying for a system that runs two tubes as it can offer about 7-8 hours of playback time from the balanced output in tube timbre.
Accessories
The package includes a silicon protective case, tempered glass screen protectors for the front and back panels and a USB type-C cable of good quality. A very nice leather protective case in blue color is available as an optional purchase for $29.99.
Power output, noise and heat management
The maximum power output of the Cayin N3Ultra is 600mW/32Ω, plenty to run various sensitive headphones and most earphones, but not class leading. It did very well with headphones like the Focal Clear or HIFIMAN Arya Organic and at the same time background noise was virtually inaudible with sensitive earphones like the Soundz Avant. The solid state mode is dead silent and in tube mode you have to use high gain with very sensitive earphones in order to hear a faint background noise. Cayin has done an excellent job to control tube microphonic noise, the N3Ultra will not produce such noise even if you tap the chassis or move it around.
The Cayin N3Ultra has excellent heat management which keeps the device very cool. I have been using the Cayin N3Ultra in my 30⁰ Celsius summer-hot room and the chassis was just mildly warm at the worst scenario. Actually, I can think of a lot of USB DAC dongles that get warmer than the N3Ultra. A stellar performance considering that there are two tubes under the hood.
Audio stuff
For the most part of the listening evaluation, I used the Cayin N3Ultra in USB DAC mode, connected to the Volumio Rivo streamer. As per usual practice the device was left playing music for about 200 hours to let the tubes settle down.
Solid state
The sound quality of the Cayin N3Ultra is nothing short of amazing and really better from what someone would expect for the category. This is a neutrally tuned dap with a balanced sound signature and emphasis on musicality without forgetting about technicalities. The solid state mode is crystal clear and transparent with excellent precision and the best technicalities of the three sound modes.
The bass is deep and impactful with great definition and layering. The textures are rather weighty and visceral, this is not a lean or dry sounding player. Dynamics are also impressive, as long as you stay within its driving range, the bass is impactful and contrasted, tight and controlled with good timing and speed.
The mid range excels in timbre realism, the sound of the Cayin N3Ultra has an analog and organic feeling with plenty of harmonic variety. The presentation is lifelike, the sound has fluidity and lushness without becoming sweet or dark. The N3Ultra is musical and engaging without compromising in clarity, separation and articulation. It will make your music sound alive without messing up with the headphones frequency response.
The treble section of the Cayin N3Ultra is vivid, well defined and extended without sounding bright but not too soft either. It is rather balanced as it has plenty of bite and energy without sounding harsh or raw and at the same time is easy to the ear and naturally toned without sounding too smooth or laid back. Resolution is excellent for the category, the sound is refined and transparent with great detail retrieval and without leaning towards sterility. The timbre is also very natural without any significant artificiality or digital glare, albeit a little bit metallic at times. What I like is that the textures remain equally weighty as in the lower frequencies so high pitched instruments sound full bodied and not skinny or dry.
The soundstage is more spacious and holographic than in competitive DAPs with THX amplifiers. Pretty wide and expansive with precise imaging, it can become even more holographic and immersive with the aid of the tubes.
The tubes
The tubes are implemented in such a way as not to mess with frequency response or add too much warmth and color to the sound. These tiny tubes are not that effective in amplifying second order harmonics as it usually happens with genuine tube implementations. You do get some pleasing distortion but the sound doesn't become too rich and pleasing as with regular, all tube amplifiers. After all, let's not forget that this is a hybrid and not a full tube device. From the two tube flavors, the classic is the one that offers the richer and more atmospheric sound.
Modern tube
The modern tube flavor has the same kind of technical performance and transparency as the solid state mode. The sound is equally crystalline and well defined to the point that you might think that nothing is happening when switching to the modern tube flavor. This is far from the truth though because after a couple of minutes you realize that the soundstage gains in holography and dimensionality, the presentation becomes more immersive and alive with extra grandness. The notes also appear to sound thicker and rounder, with a more relaxed decay while the timbre becomes more organic. The bass is also weightier, fuller and more intense than in the solid state mode but without losing dynamic impact, control, speed and definition.
Most people usually associate tubes with a smoother and maybe a touch less extended treble. This is not the case here as switching to the modern tube flavor actually adds a bit more bite and sharpness to the higher frequencies and also resolves better and is more refined. The treble is of higher quality in the modern tube flavor than in the solid state, the player resolves impressively well and presents the finest details in a more natural and effortless way.
Classic tube
The classic tube flavor adds that extra pleasing distortion that was missing from the other two modes while the sound maintains very good transparency and clarity without becoming too tubey or loose. The notes gain some extra meat around the bones, the soundstage in this mode is the most atmospheric and holographic of all three, while the timbre has the most analog and organic texture by a fair margin.
The harmonies are more colorful and plentiful in this mode and the overall presentation is more relaxed but the sound is still firm and crisp. The bass becomes thicker and more visceral but the classic tube mode is the least dynamic sounding, the bass is somewhat softer and not that impactful. Still differences are subtle and the player retains excellent technical performance and resolution in all three modes. Going back to the classic flavor, the mid range has some extra fluidity and lushness while the treble is airy and sparkling but less sharp than in the modern timbre. This is the timbre with the most “tubey” sound signature and my favorite one for listening to classical music because of the very realistic tonality, the extra expressiveness and the most atmospheric and immersive soundstage.
The line outputs
The line outputs of the Cayin N3Ultra are fixed voltage line levels bypassing volume control and headphone amplification for a clean and pure sound. They can serve as a high quality source for headphone amplifiers (portable or desktop) and integrated amplifiers in home audio systems. Furthermore, the line outputs of the Cayin N3Ultra have configurable output levels for better comparability. They can be set at 2.1V (High), 1.6V (Mid), 1.0V (Low) for the 3.5mm and 4.2V (High), 3.2V (Mid), 2.0V (Low) for the 4.4mm.
I have tested the balanced line output of the N3Ultra together with the Cayin C9, battery powered headphone amplifier, to discover that the sound signature and the overall audio quality are of the exact same high caliber as described above. The support for the dual tube timbre to both line outputs is a groundbreaking feature of the N3Ultra and the user can now enjoy his favorite sound signature with the DAP connected as a source to a headphone or integrated amplifier.
Selected comparisons
I will not engage into detailed and lengthy comparisons, the solid state sound performance of the Cayin N3Ultra is on par with competitive DAPs, like the FiiO M23 or the iBasso DX180, with some minor variations, as is to be expected, in sound shaping and signature. The same applies if you treat the N3Ultra as a battery powered, portable USB DAC/amp where it performs equally well as the competition, like say the FiiO Q15. What sets it apart from the competition though is the unique tube timbre that other similar devices don't have and this is the major selling point of the Cayin N3Ultra. Most people are going to buy it for the tubes and will not care much about limited functionality or solid state performance.
Conclusion
The Cayin N3Ultra would be an easy recommendation even if it was a solid state only DAP as the sound quality is as good as the competition. What sets it apart though, and makes it unique, is the hybrid tube design that lets you enjoy high quality tube sound from a portable DAP, something that will make you forget about the lack of wireless connectivity. After all, this is the penalty that must be paid in order to eliminate noise and enjoy crystal clear sound. People who don't stream will not care much, as for all others, you can always utilize the N3Ultra as a portable USB DAC. Be it a DAP or a portable DAC, the Cayin N3Ultra offers exceptional sound in three different flavors and is the only one with tubes at this price point.
The review sample was kindly provided free of charge in exchange for an honest review. The price of the Cayin N3Ultra is $529 and you can buy it from authorized retailers.
