Cayin Audio were R2R pioneers in a smart music player, but the advent of the R2R RU6 USB-C DAC/amp dongle establishes them as masters of the fully-discrete resistor DAC topology in portable audio. Entering 2022, this is all it takes to achieve the buttery, natural and resolving sound, plus imaging depth, R2R is known for. Building a discrete R2R DAC in N6II/R01 had already been no mean feat. Yet to have gone one further, and implemented a 4.4mm DAC dongle for Android, iPads and laptops is a most ambitious step for R2R. It's worth it to Headfonics who cite RU6's "analog" approach, and the innovation extending to its volume control is lauded by Headfonia. [See Product Desc. For More] It gets harder every time it gets smaller, so RU6 marks Cayin as masters showcasing how they can make it work. Descended from R01, RU6's boasts a chain of 96 0.1% precision, temperature stable, resistors. That imparts a fidelity to mobile audio not yet experienced. Over 200 mW of balanced power gets most earphones and headphones loud, on the move. ecoustics say RU6 "is not only very unique but also one of the best of its kind". Everyday Listening rates "RU6’s wide stage and analogue-like note presentation granting it one of the sweetest and most euphonic sounds I’ve encountered". After thorough comparisons with other options, Twister6 qualifies RU6 as capable of replacing entry-level music players. Prime Audio Reviews confirms it differentiates itself from other DAC/amps, and it's Ear Fidelity's Best Portable DAC of 2021. Your music will be decoded up and down RU6's 24-bit ladder of individual resistors, crammed into its thumb-sized chassis over two separate six-layer PCBs. The actual R2R ladder DAC is kept apart from signal processing to lower noise. We pay attention when Cayin implement RU6 ala typical R2R – with a NOS (non-oversampling) mode. That's double the feat because the precision demanded goes up. Amidst minimal digital filtering, R2R's analog-like goodness gets delivered unmolested to your ears. Lovers of reference sound need not fret, however, with RU6's ability to switch from NOS to oversampling mode for the cleanest possible result. That scrubs any last distortion and artifacts beyond the audible human hearing range, leaving you to just enjoy your music, naturally, via one more Cayin innovation yet. That precision is backed up by a low-power, fully analog, volume control solution. A series resistor operates with shunts as voltage dividers in tandem with relays, to maintain near-perfect resolution of your music and a signal-to-noise ratio of over 110 dB. A totally novel volume solution has made this a feat for a USB-powered dongle DAC; let alone a R2R one.  Take all 30g of the RU6 built from CNC aluminium with you in your pocket, bundled with a USB-C cable as stock for all your mobile devices, with additional leather cases and Lightning-to-USB-C cable (not MFI-certified) sold separately.  Also check out the rest of Cayin's releases here, or view our other DAC/amps here.

1-bit, multiple possibilities. After the debut of Head-Fi's first discrete 1-bit, all-to-DSD, music player in N7, Cayin Audio have miniaturised the technology further in RU7. This latest novel 4.4mm USB DAC/amp from innovators Cayin therefore promises to upsize your enjoyment of music with the same decoding topology that saw N7 greeted with aplomb. Built of 128 individual resistors, RU7 converts all your normal PCM playback – via CD rips, Hi-Res downloads and Spotify, Tidal or Apple Music streaming – into DSD before decoding to analog. Its size is proof that no task is too big for Cayin. Outputting in 4.4mm, RU7 is Cayin's perfect complement to the PCM, R2R, RU6. Headfonics says RU7 is "the best of the lot". Headfonia elected this mini DSD masterpiece to its Recommended Buys list. eCoustics add "it's the best dongle DAC we’ve tried yet". "RU7 continues the company’s hot streak of breaking new ground in DAC design ... 1-bit DAC in the RU7 is even more impressive than the R2R DAC [in RU6]" says The Headphone List. To Twister6 and ichos-reviews, RU7 even challenges DAPs. Bringing up to 400 milliwatts power to bear, the goodness of an all-to-DSD approach to decoding can be heard with all manner of portable Head-Fi. [See Product Desc. For More] All audio formats are passed as DSD through RU7's precise 1-bit decode. Cayin returns to Sony's Scarlet Book SACD revolution of the 1990s and elevates that conversion philosophy with modern mobile dongle hardware. RU7's highlight is its 1-bit decoder, converting all PCM files to quad-rate DSD first via DSP logic, while letting native DSD material flow on to the 128 discrete resistors in its DAC – in actuality a simple analog low-pass filter. There's zero error at the point of conversion in a 1-bit DAC. There, Cayin relies on Pulse-Density Modulation (PDM)'s total accuracy, and sheer ease of decoding. The pitch for DSD's 1-bit conversion is digital at its simplest and closest point to analog – level represented only either as a 1 or a 0, switching on or off. To achieve analog, the bitstream is simply low-pass filtered. Cayin's all-to-DSD discrete DAC is accurate ... and also elegant, breakthrough and historic in personal audio. It draws inspiration from the illustrious halls of Hi-Fi, where each EMM Labs, Nagra Audio, Playback Designs, PS Audio and of course, N7's, 1-bit DAC release has been greeted with accolades and fanfare. RU7's discrete proprietary tech immediately differentiates itself from commercial DAC chips, where IC packages are often too small to perform an ideal 1-bit conversion. RU7 also avoids the errors of dynamic element matching inherent to 2-7 bit delta-sigma decoders. The decoded analog goes through Cayin's specially designed resistor-based analog volume control for perfect channel matching at any level – facilitating that very special 1-bit discrete DSD decode and importantly preserving your music's true dynamic range resolution. A series resistor operates with shunts as voltage dividers in tandem with relays, to maintain near-perfect resolution of your music and a signal-to-noise ratio of over 110 dB. A totally novel volume solution has made this feat possible on a USB-powered dongle DAC. Cayin differentiates RU7 from RU6 in offering the former a line-out option whereby the volume control is bypassed for a fixed voltage out, perfect for listening into motor stereo systems as well as handy and portable personal speakers.  Meanwhile, RU7's 400mW output power is doubled compared to RU6's, such that this DSD DAC is capable of transferring all its forward-thinking fidelity into your prized transducers. Never fear for leaving your reference gear behind for Cayin's latest and greatest every-day carry.  There ends the list of exploits worthy of celebrating Cayin's 30th anniversary in arguably more ambitious a way than even N7 offered. Check out the rest of Cayin's gear here, or view our other USB dongle DACs here.

Protect your RU6 from scratches with one of these — Tangerine Orange or Cobalt blue, your choice.

4.4mm TRRS female - 3.5mm male single ended L-shaped quality adapter by Cayin.  

Cayin Audio, you keep outdoing yourself. When every release from these innovators is expected to be a revolution, N8II had to break significant new ground. This tube or solid-state flagship music player achieves exactly that, with upgrades on every front. N8II plays with a deftness of touch to dynamics, realistic distances and imaging, plus a soundstage bathed in a gentle light that is at the same time detailed but never fatiguing. Headfonics heard N8ii up Cayin's tube DAP game. It went right onto Headfonia's Recommended Buys list. Twister6 heard "Cayin take their original N8 DAP to a whole new level ... beyond of 'everything but the kitchen sink'". Ear Fidelity declares it a "masterclass of a DAP", with "tube and Class A a game changer". Dual ROHM BD34301EKV DAC chips make their debut in N8II and portable audio, fronted by a full Google Play Android 9 operating system. That all feeds Cayin's new timbre selector that applies to both balanced and single-ended discrete amplifier outputs. [See Product Desc. For More] Four years in the making since Cayin's original N8 made history as the first portable tube music player ever, N8II achieves what its predecessor couldn't even have begun to dream of. It doubles up on its 6P1 tube complement in its small signal gain stage, packing two Nutube dual triodes for true balanced, differential, operation from either its 4.4mm or 3.5mm outputs.  N8II's Nutubes can be turned on or off on both outputs to match your listening preferences. If you choose to bypass tubes, signal direct from the DACs runs to the power stage, benefitting your gear that loves the precise, clean detail associated with transistors. READ ALSO DAPs have gone down the tube Taking inspiration from Cayin's tube/solid-state C9 portable amplifier, N8II's differential analog design relies heavily on common-mode rejection to serve as a clean, transparent – but never sterile – flagship reference with 125dB of signal-to-noise ratio. A marvel of miniaturisation, N8II packs C9's discrete power stage, operating in switchable Class A or Class AB to put out up to 1,200 milliwatts. This bias system ensures the output of watts that are supreme in quality – a result of individual transistors being turned on and operated where their open-loop linearity is optimal to further push distortion down. Cayin leave you the ability to boost N8II's operating voltage beyond 14 volts, further ensuring transistor linearity while guaranteeing headroom for large dynamic swings on bigger cans that need it. However, it's not only about the quantity of power, but more importantly the quality. Signal integrity is key. N8II's volume control remains fully analog, eschewing a lossy digital control thanks to JRC's NJW1195A resistor ladder part, implemented only after the gain stage. Any attenuation is kept far away from the delicate output signal from new ROHM DACs – of which Cayin's implementation has been key. READ ALSO C9 – nothing is too extreme for Cayin BD34301EKV decodes DSD as a native 1-bit stream without PCM processing, owing to N8II's external analog volume control. ROHM's flagship chip's ability to output analog in current, pushing distortion figures down and upping tuning potential via N8II's extensive current-to-voltage I/V converter, also cannot be overlooked. This small-signal segment beginning from the ROHM DACs has been overbuilt for a music player. But what might be considered extreme elsewhere, is only expected from Cayin.  Currawong says "N8II is for people who must have the best DAP of its kind, regardless of the cost".  ROHM's input signal processing via dither and advanced clock handling, plus a chip layout that's been streamlined for silent operation, are also talked up. N8II's FPGA feeds a pristine I2S signal to the dual DACs, after which they are upsampled by up to 32 times before being converted according to ROHM's linear-phase digital filters. Cayin have deployed the perfect Google Play-based Android 9 UI to feed every imaginable kind of content to its shiny new digital sub-system hardware. Direct Transport Audio bypasses otherwise mandatory sample rate conversion of stock Android. So play Tidal 16X MQA, Qobuz and Hi-Res Lossless Apple Music as the file was originally encoded with full confidence, with no undue digital tampering. The flexibility yielded by Cayin's Snapdragon 660 CPU and 6GB of RAM running optimised Android 9 is phenomenal, and fully at the service of N8II – Head-Fi's most advanced and complete music player in 2022. Those wanting more horsepower yet from Cayin can look at C9 as a potential stacking option from N8II's balanced line-outs here, browse Cayin's other revolutionary products here, or view all our other music players here.

Cayin's Lightning cable for Apple users. ***Please note cable is not MFI-certified.

Cayin Audio's N30LE flagship proved so popular, they shrunk it down into a mini-me. Introducing the N3 Ultra, the entry-level tube music player with dual JAN6418 valves that yield warm, liquid sound to both single-ended and 4.4mm balanced outputs.  Baby Cayin's strengths are clear to Twister6. Headfonics says Ultra "is a huge setup from the older 2021 N3Pro version". Dual AKM AK4493SEQ DACs help bring N3 Ultra's concept into the future. Its tubes then sweeten Cayin's decoded analog. Ear Fidelity writes it's "wildly recommended ... it's just that good", praise which was echoed by Headfonia and ichos-reviews. Not content to just extend tube timbre to its balanced outputs, Cayin also adopted N30LE's dual modes to give N3 Ultra the same Classic and Modern tube flavour options. Working its JAN6418 pair either as a triode, a pentode, or turned off entirely, yields clear, audible differences that lets you find the perfect synergy with your transducers. This swappable tube signature then flows on to powerful solid-state output buffers capable of driving the low impedances of your IEMs and headphones. The evolution from Cayin's original N3Pro kick-started a tube DAP genre and indeed inspires flagships these days. But Head-Fi's foremost innovators show us first never follows, staying ahead of the curves with guaranteed hits like N3 Ultra. [See Product Desc. For More] N3 Ultra is so much more than its DAC chips, which as Asahi Kasei Microdevices (AKM)’s resurgent AK4493SEQs deserve a mention as lowering power consumption and performing better than their predecessor's metrics. Where N3 Ultra really begins to impress is the presence of its pair of JAN6418 tubes – each taking care of one channel. READ ALSO The past, present and future of Cayin tubes Placed at the voltage gain stage where it will yield the biggest sonic impact, the small output of these pentodes makes its presence heard on all four analog outputs by popular request – 3.5mm single-ended phone out, 4.4mm balanced headphone out, 3.5mm single-ended line-out and 4.4mm balanced line-out. Indeed, N3 Ultra is a huge upgrade. It throws out the lossy DAC digital volume control of its Pro predecessor – catastrophically located in the signal path before the tubes back then, already diminishing dynamic range performance before the arrival of the precious decoded analog at arguably the noisiest section of its circuit. Never again. N3 Ultra incorporates a JRC NJW1195A electronically controlled analog volume control only far AFTER its tube gain and right before its power stage, where its quality can be showcased. This resistor ladder volume control comes only after the voltage drivers, kept far from the input signal for maximum integrity, and the best signal-to-noise performance. READ ALSO DAPs have gone down the tube Cayin count on the square law function of N3 Ultra's JAN6418 to push down distortion at the drawing board. The huge operating voltages of this valve section, and their Class A operation, in a portable player means that open-loop linearity exceeds virtually every other non-tube DAP ... at any price. The signal that goes in, comes out amplified the same. You'll hear from N3 Ultra the kind of effortlessness yielded only by high operating voltages, Class A bias and the non-existent capacitance of tubes. These factors allow minimum negative feedback to be applied, as what enters Cayin's JAN6418s has little error that needs correction. You can focus on the music in either Classic or Modern – the latter working each JAN6418 as a pentode – tube modes, knowing that you're hearing back the track close to the way it was recorded. The single-ended operation of Cayin's valves emphasises even-order harmonics for natural, engaging and warm sound. And the small quantity of tube feedback means distortion remains low order, rather than complex intermodulation. N3 Ultra's highly-linear small signal is then converted to balanced and flows into the player's differential solid-state output stage. These op-amp buffers give Cayin's prodigy the grunt to drive lower impedance IEMs and headphones like Focal perfectly. In this way, you can bask in the natural allure of tube sound, and still trust your player to act as a proper voltage source, packing low output impedance and high damping factor.  READ ALSO N3 Ultra's development story You'll want to get your music aboard N3 Ultra, and Cayin build in a Snapdragon processor as well as lightweight, non-streaming Android skin to keep operation bloat-free. Microphonic control is well in place around N3 Ultra's tubes – learnt from generations of Cayin tube music players – and abundant heatsinking is applied around them to keep rising temperatures away from critical components. As evidence by N3 Ultra, Cayin don't build entry-level players. Each release is over-built to stand up to the rigours expected of it, and beyond. Check out the rest of these innovators' releases here, or view our other music players here.

It had to be Cayin. From those who gave Head-Fi the first Android-based R2R DAP, and the first similar discrete resistor DAC/amp dongle, comes N7. This all-to-DSD flagship music player is a fitting celebration of Cayin Audio's 30th anniversary. Built of 128 individual resistors and original DSP work carried on a FPGA, the fully-balanced, differential, 1-bit discrete DAC in N7 is proprietary Cayin through and through. It's "the kind of DAP that invigorates your listening experience with headgear that perhaps over time you have gotten a bit blasé about" praised Headfonics. "Cayin is putting the bar very high for themselves and the competition" added Headfonia. Twister6 wrote home about N7 after he adopted it as his daily driver for "flagship-level performance". It's a flagship bargain to eCoustics. ichos-reviews envies "the lucky owner with many hours of pure musical bliss". Cayin doesn't differentiate between CD rips, Hi-Res downloads and Spotify, Tidal or Apple Music streaming. The Android 12, Google Play Store N7 converts all your normal PCM playback into DSD.  All formats are then passed as DSD through N7's precise 1-bit decode, before signal flows on to a balanced 4.4mm discrete transistor headphone amplifier biased into Class A. [See Product Desc. For More] Caiyin's latest innovation combines the best of digital and analog technology to emerge totally unique and apart from an increasingly mature market. N7's corporeal, physical and tangible sound is unmatched by any other DAP. N7 doesn't just sound surprisingly non-digital: it's utterly realistic and true to life. Natural and chock full of resolution, Cayin's landmark release stands apart by presenting music in a spectacular yet totally even-handed way bottom to top. Cayin returns to Sony's Scarlet Book SACD revolution of the 1990s and elevates that conversion philosophy with modern hardware plus a proprietary DSP trick or two. N7's highlight is its 1-bit decoder, drawing inspiration from the Philips and Marantz DSD DACs of yore. N7 converts all PCM files to octo-rate DSD first via DSP logic, while letting native DSD material flow on to the 128 discrete resistors in its fully-balanced DAC – in actuality a simple analog low-pass filter. There's zero error at the point of conversion in a 1-bit DAC. There, Cayin relies on Pulse-Density Modulation (PDM)'s total accuracy, and sheer ease of decoding. The pitch for DSD's 1-bit conversion is digital at its simplest and closest point to analog – level represented only either as a 1 or a 0, switching on or off. To achieve analog, the bitstream is simply low-pass filtered. Cayin's all-to-DSD discrete DAC is accurate ... and also elegant, breakthrough and historic in personal audio. It draws inspiration from the illustrious halls of Hi-Fi, where each EMM Labs, Nagra Audio, Playback Designs and PS Audio 1-bit DAC release has been greeted with accolades and fanfare. N7's discrete proprietary tech immediately differentiates itself from commercial DAC chips, where IC packages are often too small to perform an ideal 1-bit conversion. N7 also avoids the errors of dynamic element matching inherent to 2-7 bit delta-sigma decoders. The delicate analog voltage waveform painstakingly decoded from DSD in N7 is precious. Cayin's R&D, invested building their own DAC, pays off as the fragile small-signal goes on to be handled by a similar discrete bipolar transistor gain stage. This design is more than up to the task of preserving the signal – mere op-amp ICs need not apply. Instead of wasting their DAC development efforts by entrusting the analog job to commercial ICs, Cayin's labour of love continued into its discrete, differential, analog stage for common-mode rejection. N7's driver section counts on all the benefits that come with a discrete bipolar design – low voltage noise, low open-loop gain and the resultantly lower negative feedback necessary, high slew rates and unity gain stability. This accurate linearity means that whatever entered N7's DAC as digital, comes out exactly the same in analog. There's a reason N7 portrays elements within the soundstage with such solidity, the aural images it generates so convincingly rendered – its small signal post-conversion is of the highest quality, and inherently stable without going into oscillation caused by too much gain product. The utmost attention is paid throughout. The results of which can be fed out as a line or pre-amp voltage to a downstream amp such as Cayin's C9ii and iBasso Audio's PB5 tube/solid-state hybrid portable amplifier. The decoded analog goes through a four-channel analog volume control before reaching the Class A discrete output amp, facilitating that very special 1-bit discrete DSD decode and importantly preserving your music's true dynamic range resolution. N7's high rails see operating voltages for its power section rise up to 14 volts, the linearity of discrete transistors assured as a result. Cayin's discrete headphone amplifier can be operated in Class AB or an optimal Class A, for sonic tweaking with your favourite earphones and headphones.  Differentiating itself from even other flagships that cling to op-amp layouts seeking THX-certification but with inordinate amounts of gain and feedforward/feedback, Cayin's linearity remains excellent already in the open-loop, owing to its high operating voltages and bias. Those ensure individual transistors are working in optimum condition. Distortion and noise are kept low, without resorting to the excessive use of negative feedback. Cayin designed a true-balanced differential amplifier to further improve N7's linearity, and you can count on common-mode rejection at its best whenever you plug in via 4.4mm preserving its resolution. It's an output stage that's direct-coupled to improve low-frequency performance, and N7 audibly plumbs the lowest bass depths. With the extension down low, phase reproduction in the audible human hearing range for taut, hard-hitting and life-like dynamics is excellent. At the tip of the power stage's spear, unconventionally large 5 ampere output transistors ensure excellent current-handling for good reason, to reap the full benefit of N7's separately regulated power supplies for analog and digital sections. Capable of following the impedances of the Empire Ears Raven, Odin and Legend Evo down low, Cayin's 30-year tradition building amplifiers that provide actual power as proper voltage sources into halving resistances continues with N7. You'll want to exploit all of N7's technical feats by getting as much of your music aboard. So Cayin built in the futuristic Snapdragon 665 SOC and 4GB of RAM to run Android 12 perfectly. A 9,000mAh battery supplies up to 10 hours of use. Stream 16X Tidal MQA and full Hi-Res Lossless Apple Music at full bit and sample rates with Cayin's Direct Transport Audio OS that bypasses detrimental Android sample-rate conversion. And voilà: there ends the list of exploits as long as Cayin's illustrious history that the discrete 1-bit DSD decoding, Class A N7 brings to market – ready to take on the next 10 years. Also look how Cayin intend to define a new era via their entire catalogue here, or view our other music players here.

Designed by Cayin to fit C9 while keeping both style and functionality. The backplate has vented grilles for heat dissipation while you enjoy hours of pristine playback time offered by the incredible C9.

Third time's the charm for Cayin Audio with N6III. They've perfected the formula for the ideal Android 12 platform – one music player that truly will keep up with all your audio needs. The trilogy continues with the C201 module built around eight Cirrus Logic CS43198 DAC chips to yield neutral, high-resolution playback, which you will start your N6III journey. After that, continue to develop the ecosystem with new DAC/amp motherboards that are subsequently released. It's easy for another Cayin to follow in the footsteps of the N6II – the first interchangeable audio motherboard that contained the entire DAC and its corresponding analog audio circuit in one whole swappable module. First never follows, but in the case of N6III there's a strong foundation laid down by its groundbreaking mid-priced predecessor. Never wanting for sound quality – even inspiring other manufacturers to produce their own copies – Cayin have taken steps forward to modernise the N6 modular concept with a Snapdragon 665, 6GB of RAM, an external long-range Wi-Fi antenna and a 50 per cent larger battery. Modules can now also be changed without separate tools. Need we mention that the signal path is fully shielded from parasitic wireless interference housed in its own isolated aluminum chassis. N6III's build only increases the noise rejection immunity of modules that are each already top-notch audio performers in their own right. [See Product Desc. For Info on C201 Circuit] The N6III is presented to you with Cayin's first Cirrus Logic DAC circuit. Continuing the tradition of being pioneers, never has the CS43198 been paired with four cascaded JRC NJU72315 analog volume controls. N6III's C201 provides fine volume level steps and crucially shunning the DAC chip's lossy onboard digital controller. Everyone knows the resolution Cirrus Logic's flagship DACs are capable off – or do they? As the first opting for an overbuilt analog volume control that can reduce both signal and noise at the same time, hence preserving dynamic range so much better, N6III/C201 is able to excavate detail close to the noise floor of your music like no other CS43198 DAC can. Cayin's C201 employs a novel parallel differential matrix DAC architecture with its eight CS43198 DAC chips. N6III's FPGA feeds each DAC chip independently with I2S signals, operating them in mono mode before they are grouped into pairs and paralleled to form full-differential output channels. To ensure optimal performance, each DAC chip benefits from discrete, symmetric power supply and peripheral circuitry. This design minimises distortion and jitter, resulting in enhanced sound density and overall audio quality. By precisely aligning the phase of all DACs, Cayin has achieved a significant improvement in the C201's sonic performance. This is an analog output performance that matches the precision of its digital decode, with their operation in balanced differential mode counting on common-mode rejection to cancel out distortion and noise. The larger PCB size that N6III affords means that C201 is able to count on 30 per cent larger board space to keep overbuilding its circuits. This robust nature is typified by the NJU72315 volume controls – these analog attenuators are unbuffered in their basic IC form, leaving the choice of subsequent driver stage to Cayin and allowing N6III to be its quiet best, achieving 130dB of signal-to-noise ratio. This high quality is preserved into your transducers as C201 loads in four Texas Instruments OPA1622s as N6III's output stage. These powerful, precise op-amps supply abundant current and mean N6III promises high damping factor while maintaining low distortion into low impedances typical of IEMs, Focals and Fostexs achieving up to 700mW on its 4.4mm output. Still the closed-loop internal gain remaining after the application of negative feedback around N6III/C201's op-amp IC analog circuit remains high. So where she really shines could be in swinging voltage, opening up the sound of any high-impedance Audio-Technica, Sennheiser and ZMF Headphones while barely breaking sweat. Its fine small-signal component also sees it serve as a line source into Cayin's other hot 2024 release, C9II, allowing you to add tubes and a Class A discrete analog circuit down the line to scale up further. C201 is a fine start to life for N6III and your journey with Cayin's latest mid-range overachiever. As you await the launch of their next audio motherboard, check out the rest of Cayin's gear here, or view our other music players here.

If you think you know how C9II sounds because it's a Class A tube/solid-state hybrid portable amplifier, Cayin Audio asks you to think again. The successor to the genre-defining C9 throws in local feedback adjustment around dual 6P1 Nutubes as well as its discrete solid-state output stage. That’s before anode voltage adjustment allows Cayin to reinvent the rule book, once again. It enters Headfonia's Hall of Fame for that. In its rawest form – with the barest minimum error correction around its Nutube voltage gain and transistor output stages – C9II is an exercise in circuit purity. It's a simple circuit that outperforms any complex one, especially in portable form factor. With Hyper mode, where operating voltage and bias gets pushed to the linear open-loop maximum, and full balanced differential operation, Cayin equipped C9II with the means to operate at its maximum in every possible mode of operation. [See Product Desc. For More] The vast majority of an amplifier's tuning comes from its initial input and voltage gain stages. Here, we see how far Cayin have come since C9 was released in 2021. A listener's ability to adjust every parameter including tube anode voltage and the feedback loop around Nutubes means up to five potential sonic signatures are possible. The operation of C9II's Gen 5 Nutube circuit in Classic mode reduces negative feedback to a bare minimum, increasing immersion with a simpler and faster circuit that avoids time lag and transient intermodulation distortion. Distortion figures also increase on paper but are of a low-order variety that is less jarring to the ear, compared to the complex intermodulation associated with unabated feedback levels. READ ALSO The full blow-by-blow story of C9II's development Here is where a good old linear open-loop circuit based on immaculate parts gain matching raises the victory flag. And that's before Class A bias and high operating voltages come into play, setting up C9II for success. You can even play with Nutube anode voltage for very audible sonic outcomes.  Throughout, C9II allows linearity specs to remain respectable even without error correction, because there are less errors to correct in the first place. Cayin's biggest asset in that regard comes from differential, balanced operation, where common-mode rejection enters the picture to amplify signal and block off non-linear distortion and noise.  While 6P1 Nutubes are always going to be the star of the show, and adaptable to sonic preferences and tastes, don't ignore C9II's solid-state input either.  Four channels of single-ended Class A Toshiba JFETs work in quasi-complementary fashion. Just NPNs, without PNP mismatches, plus even-order harmonics and square law make for a totally unique differential circuit in a portable set-up. Once you find your ideal match from five possible permutations, the input signal passes through JRC's MUSES 72320 resistor ladder volume controls – kept far away from the input and implemented only after the driver stage to preserve fragile small-signal integrity and excellent signal-to-noise ratio. This preserved resolution is handled all the way by a discrete transistor signal path. C9II's design is more than up to the task of preserving the signal – mere op-amp ICs need not apply. Instead of wasting their input stage advancements by entrusting the analog job to commercial ICs, Cayin's labour of love continued into its discrete, differential, output stage for common-mode rejection. C9II's driver section counts on all the benefits that come with a discrete FET & bipolar design – low open-loop gain and the resultantly lower negative feedback necessary, high slew rates, current-handling and unity gain stability.  Cayin's headphone power amplifier section is inherently stable without going into oscillation caused by too much gain product. The utmost attention is paid throughout. Differentiating itself from even other amplifiers that cling to op-amp layouts seeking THX-certification but with inordinate amounts of gain and feedforward/feedback, C9II's linearity remains excellent already in the open-loop, owing to its high operating voltages and bias. Those ensure individual transistors are working in optimum condition. Distortion and noise are kept low, without resorting to the excessive use of negative feedback. Cayin designed a true-balanced differential amplifier to further improve C9II's linearity, and you can count on common-mode rejection at its best whenever you plug in via 4.4mm preserving its resolution. It's an output stage that's direct-coupled to improve low-frequency performance, and C9II audibly plumbs the lowest bass depths. With the extension down low, phase reproduction in the audible human hearing range for taut, hard-hitting and life-like dynamics is excellent. At the tip of the power stage's spear, large bipolar devices work in parallel emitter-follower configuration to ensure excellent beta and current-handling for good reason, reaping the full benefit of Cayin's quad of 18650 batteries outputting direct DC and working without voltage boost conversion. These power transistors are linear enough in the open-loop, running fully biased and at high operating voltages, that they can be removed from the feedback loop with the push of a button. The reduction in feedback to simple local quantities innocuously just controlling small-signal gain means sound becomes all the more natural. A faster, simpler and more responsive circuit is just able to present musical information in a more effortless way.  Capable of following the impedances of the Empire Ears Raven, Odin and Legend Evo down low, Cayin's tradition building amplifiers that provide actual power as proper voltage sources into halving resistances continues with C9II. This is Cayin's latest exercise in old-school linear amplification brought away from the shackles of heavy hardware and into a portable future – with nary a compromise in sound, and adapted to manage the increasingly complex crossovers flagship IEMs represent. The versatility C9II yields in tuning options is only acknowledgement by Cayin for how much the portable audio market has grown. This Nutube hybrid promises to adapt to and improve your ever-changing transducers and portable sources, making you the chef that is in full control of the flavour of your audiophile nourishment. For much, much more detail into the portable technological advances C9II heralds, check out Cayin's full development story here plus the rest of their gear here, and all our other portable amplifiers here.

***Estimated to arrive first week of Feb, 2024. Material: Nappa Leather Dimensions: 205 x 195 x 66 mm Internal Storage Size: 182 x 173 x 48 mm Weight: 642grams Strap included in purchase  

--- SOLD! --- Power hasn't come in a more potent package than Cayin Audio's little desktop iHA-6. Up to seven watts per channel promises to drive every headphone with aplomb, including HiFiMAN's notorious HE-6, Arya and Susvara, plus all Dan Clark Audio FKA MrSpeakers. [See Product Desc. For More] With the ability to improve based on the quality of sources, building blocks for a fantastic desktop rig begins from the iHA-6, said John Grandberg for Innerfidelity. Its 95 per cent discrete design counts on modern power FETs to push some serious power into any pair of cans – this is not an overstatement. Power is not to be confused for loudness here. You'll be able to benefit from the inherent low internal gain typical of any Cayin discrete circuit to drive both the Focal Stellia and HE-6, plus everything in between, in the optimal range of iHA-6's volume control. For anyone familiar with what that means, it's a big deal. You'll also be able to see everything from Cayin here and all our other DAC & amp options here.

Designed for the CAYIN N3 Pro. 

--- SOLD! ---A first IEM from Cayin showcases serious credentials. Expansive sound-staging not unlike one or two higher-priced alternatives such as Campfire Audio's Andromeda underline why it's worth your attention. The Headphone List states "from the soundstage, to the resolution, to that smooth, airy treble, the YB04 enthralls you with its unique voice and astonishing performance". With four balanced armature drivers, this affordable mid-fi option brings quality previously undreamed of in this tier.