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.

The next chapter in iBasso Audio's DX340 odyssey arrives in the hybrid JAN6418 tube/solid-state Amp16. Adding to the strengths of its mothership's 1-bit DSD DAC, the rich and natural soundstage of Amp16's tubes enhances the overtones of a wonderfully immersive and transparent music player. Amp16 is still a tale of beauty and brawn, though. DX340's ability to drive difficult loads is unchanged with Texas Instruments' big BUF634A buffers present once more to push difficult loads. Its DC-input power supply continues to allow you to operate DX340 in Desktop Mode too, allowing Amp16 to output a total of 4 watts. Add the magic of tubes to iBasso's 1-bit flagship today, and enjoy countless years of enjoyment with earphones on the go, and headphones at the desk! [See Product Desc. For More] The story of Amp16 begins and perhaps ends at its dual Raytheon JAN6418 triodes. Placed at the voltage gain stage where they will yield the biggest sonic impact, the small output of these pentodes makes its presence heard on its 4.4mm balanced headphone out. iBasso count on the square law function of Amp16's tubes to push down distortion at the drawing board. The huge operating voltages of this valve section 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 Amp16 the kind of effortlessness yielded only by a huge operating voltages and the non-existent capacitance of tubes. These factors allow minimum negative feedback to be applied, as what enters iBasso's JAN6418s has little error that needs correction. Amp16 also allowed iBasso to showcase their attention to circuit detail by incorporating a JRC electronically controlled analog volume control after its tube gain stage. This resistor ladder volume control part is implemented only after Amp16's tubes, kept far from the input signal for maximum integrity, and the best signal-to-noise performance. iBasso's single-ended operation of Amp16'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. Amp16's tubes can also be bypassed for you to enjoy a purely solid-state mode and impart a more dynamic and odd-harmonic focused signature. This way, you can discover your favourite synergies and additionally conserve battery power on your mobile source device. iBasso's highly-linear small signal is then converted to balanced and flows into the player's balanced solid-state output stage for muscle. These Texas Instrument op-amp buffers are the highly-fancied BUF634As of recent iBasso, Lotoo and Shanling Audio flagship fame – they'll do their job of supplying the grunt behind Amp16's delicate tube signal, guaranteed. This hybrid combination of tube gain and solid-state power is a well-tried combination. And the BUF634As are ideal voltage sources and stable into capacitive loads, with their gain bandwidth product ensuring frequency response extends well beyond the human hearing range for excellent phase response and taut, impactful and life-like dynamics. They promise high damping factor while maintaining its low distortion into low impedances typical of IEMs, Focals, Fostexs and Rosson Audio Designs, supplying 4 watts of power when connected to its DC power supply! Still the closed-loop internal gain remaining after the mandatory application of negative feedback around iBasso's analog circuit remains high, so Amp16 can open up the sound of any high-impedance Audio-Technica, Sennheiser and ZMF Headphones. Where Amp16 exceeds all others who use the BUF634A is its ability to accept a 12 volt DC input, bypassing nominal battery and internal 8 volt rails to increase headroom and linearity, thus directly boosting the amount of swing DX340 is capable of. In fact, give this triple wonder of 1-bit, tubes and BUF634A sound a go into any of your favourite transducers at the desk. Never has a portable device at this price or size mixed immersion, natural transparency and power as convincingly in all use cases – all thanks to Amp16! Also browse DX340 here, the rest of iBasso's releases here, or view all our other music players here.

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 Raytheon 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 JAN6418s – 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.

If you're going to add a tube to a circuit then put it on the input, and that's exactly what Audio-Technica have done with their hybrid AT-BHA100 headphone amplifier. Four ECC83S tubes take care of voltage gain, leaving the heavy lifting to a solid-state power stage built from discrete components. [See Product Desc. For More] With balanced connections back and front, AT-BHA100 promises source and especially headphone versatility from the Audio-Technica stable and beyond, those from Focal, Rosson Audio Design, Sennheiser and ZMF Headphones also being present. Alternatively, share the fun and listen with a partner through the use of two single-ended outputs each with their own volume knob! Tuned with a reference sound flat from bottom to top with beautiful sparkle in the highs, this is one infinitely pleasing listen your headphones will never tire of. We've been impressed by Benchmark Media's DAC3 supplying AT-BHA-100's signal. Also check out the rest of Audio-Technica's catalogue here, or view our other amplifiers 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. Twister6 notes this portable behemoth "should last you a long time to enhance any source you pair it up with". 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.

By popular request – iBasso Audio send DX340 further down the tube with their balanced Nutube 4.4mm Amp14 amplifier card. Twister6 loved "fine-tubing" the sound! Building on Amp13, and the clamour for a balanced version on the back of its success, iBasso have come up with another Nutube module capable of swinging twice as much output voltage for bigger Focal and Fostex headphones.  iBasso's DX3XX series is a great platform to launch a design as ambitious as Amp14, with its dedicated analog section battery and extra chassis space for an uncompromising audio circuit put to great use here. Amp14 is the natural evolution for DX340, its strong liquidity and air the natural complement to one of Head-Fi's most detailed music players – despite its Nutube's cathode input providing strong immunity to Wi-Fi and external interference, in a reference implementation of Korg's direct-heated triode. [See Product Desc. For More] Placed at the voltage gain stage where it will yield the biggest sonic impact, the small output of Amp14's Nutube then gets boosted by Toshiba FET buffers. The differential stage begins there while preserving the square law function of the Nutube, and grants the voltage section enough juice to drive the rest of Amp14's solid-state output stage.  DX340's dynamic range is maintained through two NJR NJU72315 digitally-controlled analog volume parts. The fully balanced, differential, Amp14 is additionally able to count on common-mode rejection plus adequately applied negative feedback for more linearity and less distortion and noise. The separate 2,000mAh analog battery aboard the DX3XX line supplies the backbone of power for Amp14's high operating voltages, with clean, individual DC power sections for crucial parts of the module including a 14 volt supply for the Nutube's anode. Dual Texas Instruments OPA1622 op-amps make up Amp14's power stage with operating voltages of 8 volts, such that higher impedance transducers are given the swing necessary to perform. A dedicated 4.4mm line-out section on Amp14 also supplies DX340's excellent small signal to an outboard amplifier. Such is expected of a high-performance iBasso Amp14 module that yields excellent distortion and noise specifications, while capturing the romance of tubes in DX340. ichos-reviews says Amp14 completes iBasso's family of amp cards with its natural timbre. Also view Amp13 here, all of iBasso's other portables here, and our music player catalogue here.

Adding scale and stage to Feliks Audio's impressive Echo II is Elise. Tube character abounds but never enough to take away the life-like realism of actual music in this OTL amplifier in single-ended triode format, based on the 6SN7 driver stalwart. You'll struggle to dispute Elise's quality at portraying an orchestral piece of work, or its magic synergy with Audio-Technica, Sennheiser or ZMF Headphones. Give it one listen, or many. Rarely will a single piece of gear fit as many sources, genres or set-ups. [See Product Desc. For More] Its mids are liquid and forward, great to address any flaws still present in your flagship cans. Warm, natural and wholesome even harmonic sound dominates – a direct result of Elise's single-ended Class A topology. The holy grail of all bias schemes isn't undertaken lightly, and new current sources ensure Feliks Audio's classic single-ended triode amplifier runs stably fully biased at all output levels. This is a decidedly low-distortion affair in an inherently linear amplifier given high tube operating voltages and current. Transconductance increasing with bias current is optimal. And while tube imaging, emotiveness and liquidity is de facto, Elise always sounds natural and fully transparent. Indeed, despite its mid-range vivacity, a massive audio bandwidth is guaranteed given its output transformer-less OTL construction. Literally nothing separates you from your music. Pairs of 6SN7 and NOS 6N13S tubes power your headphones directly, without any chunk of iron in the signal path.  Elise champions frequency extension – the fast, deep bass and airy, open highs from the best OTL associations to perfect phase reproduction and respectable damping factor – therefore. Long tube operating lifespans come courtesy of improved thermal management and more efficient passive cooling driving up to 60 per cent lower operating temperatures in the incumbant, versus its predecessor. Really, it's never only about the parts, and Elise is further proof boasting a new tube cathode heater and power supply design derived from the flagship Euforia. Great design nous gives a premium, Polish-built amplifier the platform to perform quietly and transparently.  Whether you go up or down, you'll be served browsing the rest of Feliks Audio's offerings here, or all our other DAC & amp options here.

After the success that was DC Elite, the hybrid tube/solid-state Nunchaku DAC/amp is the one-two knockout punch from iBasso Audio in the dongle world. iBasso's flagship dongle's own one-two are dual Cirrus Logic CS43198s and JAN6418 tubes to bring your phone, tablet and laptop listening to new heights.  iBasso's hybrid DAC/amp "has now become my favourite USB DAC dongle" to ichos-reviews, who said "Nunchaku is the most natural sounding USB DAC dongle I have tested thus far and the perfect way to experience tube sound on the go". With a voltage gain stage of Raytheon valves feeding a power stage built upon Chi-Fi's favourite power op-amp, the BUF634A, Nunchaku's kung-fu could truly elevate dongle DACs to music player levels of fidelity in 2025... [See Product Desc. For More] The story of Nunchacku begins and perhaps ends at its dual Raytheon JAN6418 triodes. Placed at the voltage gain stage where they will yield the biggest sonic impact, the small output of these pentodes makes its presence heard on its 4.4mm balanced headphone out. iBasso count on the square law function of Nunchacku's tubes to push down distortion at the drawing board. The huge operating voltages of this valve section in a device as small as this DAC/amp means that open-loop linearity exceeds virtually every other non-tube dongle or DAP ... at any price. The signal that goes in, comes out amplified the same. You'll hear from Nunchacku the kind of effortlessness yielded only by high 22.5 volt operating voltages and the non-existent capacitance of tubes. These factors allow minimum negative feedback to be applied, as what enters iBasso's JAN6418s has little error that needs correction. Nunchaku also allowed iBasso to showcase their attention to circuit detail by incorporating a JRC electronically controlled analog volume control after its tube gain stage. This resistor ladder volume control is implemented only after Nunchaku's tubes, kept far from the input signal for maximum integrity, and the best signal-to-noise performance. iBasso's single-ended operation of Nunchacku'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. Nunchaku's tubes can also be bypassed for you to enjoy a purely solid-state mode and impart a more dynamic and odd-harmonic focused signature. This way, you can discover your favourite synergies and additionally conserve battery power on your mobile source device. iBasso's highly-linear small signal is then converted to balanced and flows into the player's balanced solid-state output stage for muscle. These Texas Instrument op-amp buffers are the highly-fancied BUF634As of recent iBasso, Lotoo and Shanling Audio flagship fame – they'll do their job of supplying the grunt behind Nunchaku's delicate tube signal, guaranteed. The hybrid combination of tube gain and solid-state power is a well-tried combination. And the BUF634As are ideal voltage sources and stable into capacitive loads, with their gain bandwidth product ensuring frequency response extends well beyond the human hearing range for excellent phase response and taut, impactful and life-like dynamics. They promise high damping factor while maintaining its low distortion into low impedances typical of IEMs, Focals, Fostexs and Rosson Audio Designs, supplying over 1 watt of power in such cases! Still the closed-loop internal gain remaining after the mandatory application of negative feedback around iBasso's analog circuit remains high, so Nunchaku can open up the sound of any high-impedance Audio-Technica, Sennheiser and ZMF Headphones. In fact, give this triple wonder of Cirrus Logic, tube and BUF634A sound a go into any of your favourite transducers – the results will be surprising, never has it been done before. Check out how you can upgrade via iBasso's music players when you're done here, or view all our other DAC/amp dongles here.

Purity of sound is everything that Feliks Audio is about, and Euforia EVO is the full realisation of that legacy. This uber-revealing output transformer-less OTL tube amplifier built on the CV-181 (6SN7 derivative) unearths every detail in your music. Now with a 4-pin XLR output for balanced connections, EVO bears similar upgraded parts broadly carried over from the Feliks Euforia Anniversary Edition. EVO is a Headfonics pick for hours of fatigue-free listening, a Headfonia Recommended Buy, an Audiophile-Heaven Hall of Fame-r, and "wildly recommended" by Ear Fidelity. Headphonesty say Euforia EVO is "absolutely sublime". UPOCC copper wiring in the signal path, enhanced coupling capacitors and a power transformer with great AC line performance come as standard. EVO sets a new benchmark of stock transparency that will serve you well with many an Audio-Technica, Sennheiser or ZMF Headphones. Feliks present the Euforia line its latest, timeless, new member ... in a beautiful satin gloss black finish packing sound quality that will remain unrivalled for years. [See Product Desc. For More] As another single-ended triode amplifying in Class A, EVO remains fully transparent and yet never overbearing in its presentation of detail. Natural and wholesome even harmonic sound dominates – a direct result of EVO's single-ended Class A topology. The holy grail of all bias schemes isn't undertaken lightly, and rock-solid current sources ensure Feliks Audio's flagship OTL runs stably fully biased at all output levels. This is a decidedly low-distortion affair in an inherently linear amplifier given high tube operating voltages and current. Transconductance increasing with bias current is optimal. And while tube imaging, emotiveness and liquidity is de facto, EVO always sounds natural and fully transparent. Certainly, a massive audio bandwidth is guaranteed given its output transformer-less OTL construction. Literally nothing separates you from your music. Pairs of transparent CV-181 drivers and NOS 6N13S tubes power your headphones directly, without any chunk of transformer iron in the signal path.  View this post on Instagram A post shared by Headphonesty (@headphonesty) This Feliks champions frequency extension – the fast, deep bass and airy, open highs from the best OTL associations. Phase reproduction in the audible human hearing range is stellar, and dynamics crash especially potently bottom to top, rivalling even the best solid-state competition. Boasting a new 4-pin XLR connection, EVO eschews the headphone cable adapter you might have used with its predecessors, powering your flagship cans even more directly in the spirit of maintaining total purity. This makes the case of EVO being the only amplifier you need – at least, till you aim for the extreme Envy... Whether you go up or down, you'll be served browsing the rest of Feliks Audio's offerings here, or all our other DAC & amp options here.

--- 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.

Cayin Audio bring the KT170 – the golden boy of vacuum tubes – to Head-Fi for the first time in Soul 170HA. This Class A flagship specimen of a tube amplifier is capable of outputting up to 18 watts per channel into HIFIMAN's Susvara Unveiled. Beating every other household tube amp builder to debut the KT170 in a commercial amplifier, all of Cayin's tube expertise has been distilled into building a flagship product around this exciting new valve model. To The Ear, "the fact is the Cayin Soul-170HA is a seriously well-engineered and well-endowed headphone amplifier able to go toe-to-toe with alternatives at its price point and some way above". Eddie's Hifi Audio World's full teardown highlights the extreme attention to detail paid to its development. [See Product Desc. For More] Massive EI core output transformers plus dual power transformers for the high and low voltage sections are designed and wound in-house, to Cayin's exact spec. These allow Soul 170HA to take total advantage of its choke-input power supply, transferring pure potency to your giant flagship headphones. But don't let such raw power scare you, your sensitive Focals, ZMF Headphones ... or even your IEMs. Soul 170HA retains the sensuality that has defined Cayin alongside brute strength. This behemoth on its XLR outputs turns delicately tactile on its alternative 4.4mm output – 18 would-be watts usefully reduced, to a maximum of just 4 watts. It is this Jekyll-and-Hyde nature of Soul 170HA – enabled by the different taps on its output transformers – that means Head-Fi should take this flagship very seriously. A JRC MUSES72320 volume control shows up, proving how Cayin meant for more than just Susvara, Abyss Headphones and Dan Clark Audio owners to enjoy this do-it-all amp. These resistor ladder electronic volume parts preserve signal-to-noise ratio and channel balance down to the ALPS-controlled encoder's lowest level – perfect for however much, or little, travel you need.  Not a one-dimensional bull in a china shop, Soul 170HA still adds all the fidelity and finesse you can reap from the whole world of flagship equipment that can be enjoyed today – gear that's easy to drive, including IEMs, is certainly not exempted. Cayin naturally provides all the fidelity, and power, the Susvara Unveiled needs. But when that speaker-amplifier level of power's not needed, Soul 170HA has more than enough fidelity to stand upon that alone and make its case. Built to work in single-ended Class A, Soul 170HA preserves the all-important even harmonics that tube enthusiasts crave. Certainly none of those push-pull, odd harmonic nasties that's a painful shortcut to easy output power yet a route to non-linearities in the process. With Soul 170HA's huge, regulated power supplies, Cayin have ensured its single-ended KT170 pair sit in their sweet spot of bias and operating voltage, while outputting their huge power. Said power supply is perfectly designed to lavish New Sensor Corp's 2021 wonder tube's great plate dissipation and robust cathode. Housed in a separate chassis, comprised of dual toroidal transformers – one for the massive voltages of tubes, and a different one for the low voltage sections to avoid contamination – Cayin tagged these to a huge choke input.  This choke operates in tandem with a capacitor bank and regulation to ensure Soul 170HA enjoys vast power reserves. Soul 170HA's reservoir is unleashed into impossible loads during big transients via dual umbilical cords connecting the two chassis, so that neither feed contaminates the other. Cayin's protection from interference is yet another factor that adds up to Soul 170HA's fidelity – and the resulting point of owning one. Soul 170HA will undisputedly improve any transducer you use, whether or not you require all 18 watts off its 4-pin XLR, or barely approach the limit of its ubiquitous 4.4mm's max 4 watts. Soul 170HA can attribute that claim to its excellent linearity in the open loop. What enters comes out the same, not relying on the excessive use of negative feedback. Without counting on common-mode rejection, its achievement of 110dB signal-to-noise ratio is a great feat and testament to thorough, good old-school engineering. A point-wired, simple tube circuit guarantees purity. Custom-built AudioCapX MultiCap coupling capacitors in Soul 170HA's signal path are ideal for passing low frequencies and extending bass flat (-1dB) down to 10Hz! Phase reproduction in the audible human hearing range remains stellar as a result, with taut dynamics and impactful bass slam – not the wooly affairs of yesteryear's transformer amps. Helped by huge output transformers, with enough inductance to reproduce sub-notes low, plus Cayin's hand-wound EI shape to allow high frequencies through, Soul 170HA performs very satisfactorily in moving drivers full-range ... and is even capable of transferring its full 18 watts of ultra-linear power out into high-impedance, high-sensitivity speakers through taps on the rear. Again the reasons for Soul 170HA's range of highest possible output power, to delicate and soft playback, surface clearly: to reproduce its magnificent KT170 tube fidelity into any kind of load possible. Buy Cayin's champion now, and rest forever assured you have the best foundation for flagship tranducers – present and future – to perform. But if space and weight are a constraint, however, look towards Cayin's own HA-300B and HA-6A in more compact form factor for Susvara-driving power still. And, when on the go, bring out one of Cayin's DAPs here, as you browse the rest of our desktop equipment here too.

After the flagship N30LE music player that ended up receiving rave reviews for leashing AKM's vintage AK4499EQs to tubes, Cayin Audio are back with a valve iDAC-8 DAC/pre-amp that repeats the feat with the new AK4191EQ – AK4499EXEQ tandem. AKM's flagship digital ecosystem makes the claim to be the top dog among chips today, and iDAC-8 counts on that as it outputs via a quad of 6H6b-B tubes ... or its alternative, selectable solid-state path. Sophisticated, open and airy, there's a refined flavour imparted on top of iDAC-8's neutral yet forgiving transparency. Cayin intends for iDAC-8 to be used in tandem with their matching iHA-8 and iDAP-8. Its I2S and AES/EBU inputs certainly allow it to be a wonderful intermediary in digital-to-analog conversion duties.  iDAC-8 makes for a wonderful tube or solid-state pre-amp too. No matter how well its AK4191EQ's 64-bit digital filters and volume control perform, Cayin didn't opt for half-measures here. A JRC NJW1195A analog volume control is built in to avoid any digital loss, to preserve the resolution of iDAC-8 at any attenuation level. [See Product Desc. For More] A modern-day DAC is so much more than its DAC chips, and Cayin have gone the extra mile in hope of everyone seeing the extent of their efforts.  They ensure the very best platform for Asahi Kasei Microdevices (AKM)’s resurgent flagship DACs to make their mark. Back on their feet with a clean slate, AKM started afresh expanding the basic footprint of a single DAC chip IC into three separate parts – to similarly multiply capabilities by a factor of three. AKM’s AK4191EQ DSP is the brains of the operation, receiving pristine I2S clocking and data from Cayin's MCU. Aboard, AK4191EQ’s delta-sigma modulator takes advantage of its expanded, dedicated, silicone footprint to lay claim to the title of the first chip IC working at seven bits. These seven single-bit modulators flow on into Cayin's AKM 4499EXEQ DACs, one for each channel and built with a single purpose in mind: to turn the interpolated, noise-shaped, digital data it receives into the most precise analog waveform possible afforded by its large footprint. Silicone size matters when it comes to a great DAC IC, and AK4499EXEQ has it. Enabled by much more exact, matched resistors and capacitors aboard for precise DC single-bit decoding, plus dynamic element matching that is less burdened by switching errors – granted by parts accuracy from a bigger footprint. Any conversion errors from AK4499EXEQs outputting in current manifests as DC offset, and not total harmonic distortion, that is easily filtered out. Current analog outputs are expected of any source claiming to be high performance. Cayin's current-to-voltage I/V section follows these AK4499EXEQs, befitting of more expensive DACs and indeed chips that output analog in current for best distortion performances. Four 6H6b dual-triodes follow, divided into two separate pairs that each take care of balanced and single-ended outputs respectively. That's to implement each output specially, with Cayin paying particular attention to iDAC-8's RCAs – with which you can feed their Single-Ended Triode tube amps HA-2A, HA-3A, HA-6A and HA-300B particularly confidently bypassing the latter's input transformers for a cleaner, shorter signal path. These single-ended tubes operate in parallel and supply voltage gain in the stage where they will make the greatest sonic impact, before getting boosted by a Vishay FET buffer. This transistor preserves triode square law, and lowers output impedance to 60ohms granting iDAC-8's RCAs enough juice to drive downstream amplifiers. This low output impedance also ensures there's no risk of a high-pass filter forming with the input resistance of another amp. And to further prevent any loss in low frequencies, large coupling capacitors sit at iDAC-8's output to extend its full-range reproduction capably to 5Hz at -3dB. Phase response is therefore excellent in the human hearing range, preserving taut and fast bass. Its high frequencies also soar above 100Khz for preservation of pinpoint musical imaging, should you ever use this overachiever in a stereo speaker system. Its built-in analog pre-amp also keeps dynamic range high, even when you listen soft. These little elements in the signal path hint at Cayin's typical attention to detail. Its overbuilt power supply announces their extravagance in material cost building an affordable compact DAC. An over-specified 45 watt toroidal transformer, nearly 30,000 uF of filter capacitance, linear voltage regulators, dedicated tube and solid-state output supplies plus low-dropout regulators complete this mini-masterpiece of ambitious engineering. You'll want to connect as many of your digital sources as possible to iDAC-8. I2S compatibility is guaranteed via Cayin's own iDAP-6 and iDAP-8, as well as AES/EBU from Matrix Audio's Element S and iFi Audio's NEO Stream. CD players enjoy AES/EBU and coaxial RCA connections. And even TV audio benefits from its tube stage via optical. Check out the matching family iHA-8 and HA-2A for iDAC-8 today. Or, view the rest of Cayin's gear here, and our other desktop items here. 

If HA-6A and HA-300 MKII were amps you would argue for, HA-2A is the one that's impossible to argue against. Building on HA-3A's success, Cayin Audio again wrapped a single-ended Class A NOS tube amplifier into a compact A4 size for the desktop ... but reduced size, weight and cost at the same time! HA-2A does that, but it's no OTL pussycat despite its reduced size and weight. More than anything, Cayin's baby of the bunch brings the benefits of output transformers designed and built in-house to meet the power requirement demands of modern headphones – both planar-magnetic and dynamic, high or low impedance. [See Product Desc. For More] Flexibility might be the first topic discussed with the lightweight and compact HA-2A, but compromise in quality was never an option. Headfonics say "HA-2A is a very endearing and well-equipped compact tube amplifier for space-conscious audiophiles". Cayin's point-to-point wiring is de facto again for signal integrity, and HA-2A's EI core output transformers surpass even HA-3A's, extending signal out to 50Khz. That frequency extension up high will already yield great improvements in HA-2A's mid-range and treble compared to HA-3A, with Cayin's latest preserving phase response in the human hearing range that much better for superior sound-staging, dynamics and imaging precision. Mixing fidelity that was once the domain of Output Transformer-Less (OTL) amplifiers in the same desktop footprint as iDAP-8 and iDAC-8, with actual power – all while reducing in price – is a true feat of Cayin.  The sense of value doesn't stop there, with premium New-Old Stock (NOS) valves – US-production Amperex ECF-82/6U8 driver and 17BF11 power tubes from the 1950s – included. Operating the ECF-82/6U8 only as a triode unlocks load line and soft-clipping functions at the drawing board. Their presence at the voltage gain stage is significant, where the majority of an amplifier's final sound signature is defined. HA-2A's novel implementation of the composite designs of both these driver and power tube types make for very interesting transfer characteristics and distortion curves. Still, linearity is a given through the holy grail of bias operation, even at this price point, while tube voltages allow for large operating points. Measured distortion is below even the threshold of HA-2A's bigger HA-6A and HA-300 MKII brothers.  And any distortion will be of the even-order variety expected of single-ended Class A amplifiers, for a smooth, warm and holistic sound. In there is Cayin's promise – for low cost of entry, weight and size, the flagship trappings of HA-2A are impossible to deny. Class A bias, high tube operating voltages, low capacitances, even-order harmonics and premium EI core output transformers ensure HA-2A gets mentioned over similarly-priced solid-state competitors, and even higher-priced tube alternatives. Even its power transformer is a loosely-wound EI core for greater AC line performance over a conventional toroid, avoiding saturation more naturally plus the negative effects of the latter's high magnetic flux and coupling between primary and secondary windings. Even for those shopping with limitations to size and weight, HA-2A's power supply is fully regulated and absolutely sounds like an offering without limitations. Particularly if Audio-Technica, Sennheiser and ZMF Headphones are your typical port of call.  As for those without space or weight constraints, make the HA-6A and HA-300 MKII your first candidates, or view Cayin's other offerings here and our other desktop amplifiers here.

iBasso Audio imagined tube magic in DX320 Max TI, and so conceived PB5 'Osprey' – losing the ROHM DACs, but gaining you two Korg Nutubes for a 4.4mm balanced tube/solid-state hybrid portable amplifier. Indeed, PB5's output stage should appear very familiar to fans of DX320 Max TI, packing iBasso's expertly designed, proprietary discrete stepped resistor volume control, Super Class A output stage and an over-the-top, clean power supply of six separate batteries. It goes right onto Headfonia's Recommended Buys list. It is Headfonics' "favourite portable amplifier I have had the pleasure to review". Twister6 praises PB5's "analog texture with bigger soundstage expansion" before becoming a dynamic duo with D16. It's in Audiophile-Heaven's Hall of Fame. While DX320 Max TI is a distant memory, its PB5 descendant could arguably ascend to greater heights.  As a fully analog product PB5 grant you the ability to line-in via today's amazing DAP sources ... while retaining the other aspects that went so far in defining iBasso's greatest flagship DAP. And adding tubes. Head-Fi now finds itself blessed with accessible opportunity. DX320 Max TI was more than a product but the birth of the super portable concept that has more applications than one. PB5 is such an example, iBasso's gift to the masses helping listeners enjoy the vast majority of DX320 Max TI solid-state output stage plus tube magic and – whisper it quietly – perhaps even surpass it with a high-performance DAC/DAP source of your choice. [See Product Desc. For More] Whisper it quietly, indeed. PB5 works near-silently because iBasso's stepped resistor analog volume control shows up where it could be most crucial – in their first battery-powered tube and solid-state hybrid amplifier. Said stepped attenuator preserves the resolution of your best DAP sources in the presence of Nutubes that may not otherwise share the same noise performance as the rest of PB5's carefully assembled transistor circuit.  Before that begins to sound like a problem, the gains from inserting Nutubes into PB5's (read: mini DX320 Max TI's) signal path far outweigh any cons. Beyond granting the kind of natural, spacious and effortless sonics tubes are known for, Korg's fluorescent 6P1 dual triodes pay dividends on the circuit design front too. READ ALSO The benefits of adding input tubes to a circuit As triodes, Korg's 6P1s provide iBasso access to an all-important square law transfer function for wide operating conditions. With tubes – audio's long-established ideal input device – now working differentially in balanced push-pull configuration to receive signal from your 4.4mm source, iBasso's proprietary stepped resistor attenuator takes charge of volume. Additionally counting on common-mode rejection, it's this proprietary volume control that enables PB5 to play it delicately into your flagship earphones for enjoyment at realistically lower volume levels. Because, it's easy to play it loud, but everyone knows it's in playing back tiny sounds that is the litmus test of a hybrid tube/solid-state amp capable of outputting as much SPL as PB5. Transparent at any volume setting down low as much as up high, with virtually perfect +/-0.1dB channel-matching, this iBasso tubed behemoth exposes detail buried deep around the noise floor of your music. So begins the rest PB5's fully-balanced, true differential solid-state circuit whose push-pull operation produces odd harmonic distortion that dovetails perfectly with the naturalness of its Nutubes. Built with individual transistors of iBasso's choosing allows great control over PB5's tuning, while an immense operating voltage over 16 volts grants an innately linear open-loop circuit, with substantially less negative feedback, to be fashioned. At the tip of PB5's spear are buffers capable of outputting more amperes of current than is needed in reality, while keeping output impedance near zero. Said power stage is another call for iBasso's Super Class A to appear.  Current mirrors ensure PB5's push-pull operation works without crossover distortion, yielding Class A-like performance at all power output levels. That makes for extremely linear open-loop operation before negative feedback is applied ... yet mostly avoids the heat and inefficiency typically associated with Class A designs. With superb damping factor as a voltage source, enough standing bias current and signal-to-noise performance to follow today's flagship IEM impedance down low, you still know PB5 will be even more in its element pushing TOTL headphones. That's especially when you consider its six separate batteries providing clean, independent power to each critical section of PB5's circuit. Everything from Focal to a Fostex and Rosson Audio Designs plus Yamaha and ZMF Headphones is applicable. Flexibility is the operative word here and sources like Cayin Audio's N7, iBasso's own DX260 plus HiBy Music's RS6, R8II and RS8 will be queuing up to lend their signal to PB5. PB5 is the perfect segway to add tubes to your portable flagship sources, but it's so much more. Through Osprey's stepped attenuator volume control and Super Class A output stage, DX320 Max TI's spirit lives on. Check out the rest of iBasso's sources for PB5 here, or view our other DAC/amps here.

Named after “NARUKAMI”, this headphone amplifier/pre-amplifier, “HPA-KG NARU” has been carefully crafted to capture the intricate details and emotional depth of sound, offering a unique, refined, and natural listening experience. NARUKAMI intertwines the majesty of nature with human innovation, combining Audio-Technica's expertise - over 60 years of pursuing the purest analog sound – with the transcendent aesthetics of KUROGAKI, an ancient wood treasured by Japanese nobles and literati with a rare, ink wash painting-like pattern.  “HPA-KG NARU” is not just a headphone amplifier; it also serves as a preamplifier with output functionality. It can drive power amplifiers using the signal from the output transformer driven by TA-300B vacuum tubes, making it suitable for use as a preamplifier for speakers. To accompany the amplifier, a limited-edition NARUKAMI Headphones “AW-KG NARU” has been exclusively designed with the same KUROGAKI wood housing as the amplifier, featuring specially tuned sound characteristics. Each set comes with a custom-made headphone cable, ensuring an exceptional listening experience. The output transformer features a headphone matching circuit with three impedance positions, allowing users to choose the impedance that best suits their headphones' characteristics and desired sound quality. The amplifier also features a convenient volume balance control knob, allowing users to adjust the volume balance between the left and right channels according to their individual preferences and requirements, and provides a 4.4mm XLR 4-pin balanced headphone socket, as well as a 6.3mm single-ended headphone socket, ensuring true versatility. The circuit design incorporates the use of the finest components available. This includes: Lundahl's LL1532 input transformer. Custom-made Lundahl Amorphous Core Silver Wire Output Transformer LL2765AgAM, offering extremely low magnetic hysteresis loss, high saturation magnetic flux density, and excellent frequency response. High-quality TAKATSUKI TA-300B vacuum tubes handcrafted in Japan, carefully selected specifically for headphone amplifiers for robust driving power and high-quality sound. AmTrans's premium audio aluminum shell resistor with exceptional heat dissipation properties. Custom-designed power transformer for independent power supply to L/R channels by Someya Denshi. SRPP circuit with rare JJ ECC83S-gold vacuum tubes, providing a rich and flavorful sound.

If HA-6A and HA-300 MKII were amps you would argue for, HA-3A is the one that's impossible to argue against. Cayin Audio managed to wrap a single-ended Class A 6V6 tube amplifier into a compact A4 sized package, for desktop headphone versatility. Weighing in at just over 10KG, not one gram is wasted with Cayin packing their famed power and output transformer iron into even the smallest member of the pack. It immediately leapt onto Headfonia's Recommended Buys list for a reason. HA-3A is Headphone Guru's "slice of heaven", bringing the benefits of transformers designed and built in-house to meet the demands of modern headphones – both planar-magnetic and dynamic, high or low impedance. [See Product Desc. For More] Flexibility might be the first topic discussed with the lightweight and compact HA-3A, but compromise in quality was never an option. Cayin's point-to-point wiring is de facto again for signal integrity, and the EI core output transformers utilise their shape to take the transparency of 6V6 power tubes out beyond the human hearing range. These power tubes popularised by their use in Gibson and Fender electric guitar amplifiers are run in single-ended Class A. Linearity is a given through the holy grail of bias operation, even at this price point, while tube operating voltages allow for large operating points. Distortion is below even the threshold of HA-3A's bigger HA-6A and HA-300 MKII brothers – clipping theoretically only occurring beyond the former's maximum power envelope.  And any distortion will be of the even-order variety expected of tube amplifiers, for a smooth, warm and holistic sound. Tube rectification rounds out HA-3A's fully-regulated linear power supply built around Cayin's in-house toroidal power transformer. In there is Cayin's promise – for low cost of entry, weight and size, the flagship trappings of HA-3A are impossible to deny. A fully-regulated linear power supply, Class A bias, high tube operating voltages, low capacitances, even-order harmonics and EI core output transformers ensure Cayin's baby of the bunch gets mentioned over similarly-priced solid-state competitors, and even higher-priced tube alternatives. For those shopping with limitations to size and weight, HA-3A absolutely sounds like an offering without limitations. Particularly if Audio-Technica, Sennheiser and ZMF Headphones are your typical port of call.  As for those without space or weight constraints, make the HA-6A and HA-300 MKII your first candidates, or view Cayin's other offerings here and our other desktop amplifiers here.

For OTL tube manufacturers Feliks Audio, the route to the top of Head-Fi's hill ran contrarian with massive output transformers – and still proved to be the Envy of everyone. A flagship powerhouse amplifier, its design centered around famed 300B tubes. While the brand's OTL amplifiers had proven to be delicate, pure and low-powered affairs, there is nothing subtle about the construction of Envy. Feliks set out to build the ultimate tube amplifier pushing over 5 watts of Class A power at clipping. Stereophile "admit to being taken by the Envy's bold but tasteful style ... it's top-of-the-world wonderful". Effortlessly able to drive Susvara – in fact lauded by Ear Fidelity and Secrets of Home Theater and High Fidelity as the best headphone amp they've heard HIFIMAN's flagship through – Envy is a true statement of ambition by these prolific Poles. Headfonia warn it'll be the Envy of you after electing it to their Recommended Buys list, similar to Soundnews who gave it an Editor's Choice award. And Headfonics call it an essential demo if you want to elevate any elite flagship headphone – echoed by Hifi Pig. [See Product Desc. For More] As you'd expect of a statement amplifier, Envy can have no weaknesses. Depending on output transformers for brute power, this Feliks flagship still retains all the purity that this brand has come to be defined by. It's a champion of frequency extension both up and down; chunks of iron in the signal path or not. Running in single-ended Class A to preserve the all-important even order harmonics triode enthusiasts crave from such topologies, Envy is inherently linear. Its high operating voltage and high bias means that its entire circuit operates stably with zero feedback. That's aided by the use of 300B tubes providing Feliks Audio access to square law and load-line characteristics to push distortion down from the drawing board. Triode plate impedance also means that any clipping is soft and graceful, veering from harshness. Running in the open loop doesn't stop Envy from producing enormous frequency extension up to 100Khz at -3dB. The preservation of high-frequency triode transparency is certainly no mean feat without the aid of negative feedback. Meanwhile, the finest coupling capacitors and its large output transformers sees low frequencies plumb down to 8Hz – truly subterranean levels, for a tube amplifier of any sort. WATCH ALSO Timelapse: the painstaking hand-assembly of Envy This Feliks frequency extension pays off in truly flat phase reproduction in the audible human hearing range, for impactful bass and realistic portrayal of musical images. Dynamics are life-like and on par with the best solid-state amplifiers. Indeed, none of the resolution Feliks Audio has been associated with from its OTL work has been lost in Envy, bearing uber-revealing CV-181 drivers from Psvane. But users wanting to squeeze the final drops of detail have the opportunity to build this behemoth in its Performance Edition, featuring UPOCC point-to-point copper wiring, and upgraded 300B power tubes from Electro-Harmonix to Full Music for the ultimate signal path. Inside and outside, Envy is a prestige product that belongs in a reference Hi-Fi rack. Its balanced pre-amplifier outputs allow you to operate it just that way into a full-sized, stereo power amplifier, passing through the entire 6SN7-300B stage and out through the rear. Definitely place Envy somewhere prominent: you won't be able to tear yourself away from gazing upon its beautiful wood build, nor hearing this pinnacle, for long. Otherwise, seek Feliks Audio's other OTL builds if you're looking for a smaller footprint here, and our other amplifiers here.

Nutubes return to iBasso Audio, bigger and better through Amp13 for DX340. The size and power supply afforded by their flagship music players allowed iBasso to take this tube design to new heights. That extra circuit board space has allowed Korg's sixth-generation Nutube direct-heated triode to achieve new levels of signal-to-noise ratio, transparency and output power. Holding its own even against its balanced Amp14 sibling, iBasso's Amp13 brings plenty of even-order harmonics to sweeten synergies given its single-ended operation throughout. Eschewing bridge-tied load operation means Amp13 also outperforms its counterpart into low impedances. Headfonics confirm Amp13 does all the above, offering the liquidity tube lovers desire. Musicality won out for Audio-Ph. Upgrading to iBasso's mature Nutube tech was totally worth it to Audiophile-Heaven. [See Product Desc. For More] Placed on Amp13's voltage gain stage where it will yield the biggest sonic difference, this Nutube's small output then gets boosted by a Toshiba FET buffer. This preserves Amp13's triode square law, and grants it enough juice to drive the rest of the solid-state output stage.  READ ALSO DAPs have gone down the tube iBasso built Amp13 with dual 3.5mm outputs. The hybrid Nutube section directly feeds Amp13's low noise, low output port (2.5Vrms) for sensitive IEMs. Meanwhile, an intermediary solid-state driver stage gets added for the high output port (4.1Vrms) to push Focals and Fostexs needing more gain. DX340's dynamic range spec is maintained through NJR's NJU72315 digitally-controlled analog volume part, and iBasso hide yet another trick up their sleeve: forcibly driving the ground signal of Amp13 to increase output power and reduce noise. The separate 2,000mAh analog battery aboard the DX3XX line supplies the backbone of power for Amp13's high operating voltages, with four clean, individual DC power sections for crucial parts of the module. The anode packs 21 volts of supply, while eight volt output rails continue to maintain excellent open-loop linearity before negative feedback. Such is expected of a high-performance iBasso Amp13 module that yields excellent distortion and noise specifications, while capturing the romance of tubes in DX340. Also view Amp12 here, all of iBasso's other portables here, and our music player catalogue here.

Cayin Audio’s HA-300 MKII is upon us, to ensure the modern headphone enthusiast can continue to enjoy the magic from historic 300B tubes with any headphone. Important refinements over its predecessor include a MUSES72320 resistor ladder electronic volume control part. This preserves signal-to-noise ratio and channel balance down to the ALPS-controlled encoder's lowest level – perfect for however much, or little, travel you need. A 4.4mm output ensures yet more headphones can be plugged in via Pentaconn’s ubiquitous connector for transformer-balanced operation. With headphones having developed leaps and bounds since the turn of the decade, Cayin guarantee their latest and greatest flagship keeps up with the times. That was exactly as Headfonics discovered, such that any can thrown at it performed in ways not thought possible. [See Product Desc. For More] HA-300 MKII has been built again as a Class A single-ended triode amplifier to preserve the all-important even-order harmonics audio enthusiasts crave from such topologies. But Cayin's flagship remains a truly reference device. The direct-heated magic from Genelex PX300Bs – bearing the Gold Lion mark of quality – continues to provide Cayin with access to square law, load line and graceful soft-clipping triode functions at the drawing board to push down distortion without the crutch of negative feedback.  HA-300 MKII's high tube operating voltage ensures excellent open-loop linearity and additionally reduces the need for negative feedback. Clean power is supplied by a physically separated power supply built around a massive toroid. A choke input in tandem with a huge smoothing capacitor locks stable, quality, DC power in place without sag, post 22DE4 tube rectification. Indeed, power supply regulation is thorough, extending beyond typical small signal regions to encompass even the power stage and high-voltage sections of the amplifier. Huge EI-core output transformers with reinforcing shielding are wound in-house to Cayin’s exact spec for frequency extension at the extremes, lowering impedances and providing immense inductance for the lowest bass reproduction, plus great top-end transparency owing to their shape. Custom-built AudioCapX MultiCap coupling capacitors upgraded for MKII's signal path are also ideal for passing low frequencies and extending bass down to 10Hz. Phase reproduction in the audible human hearing range remains stellar as a result, with taut dynamics and impactful slam – not the wooly affairs of yesteryear's transformer amps. That high bandwidth gets delivered into any working personal audio transducer, with HA-300 MKII's output transformers allowing it to drive low-impedance, low-sensitivity planar-magnetic headphones balanced via 4.4mm and 4-pin XLRs pushing up to 6 watts on the front. That potent Class A power can even be switched to speaker terminals on the rear to drive high-impedance, high-sensitivity passive speakers from the likes of Rogers, DeVORE Fidelity or Zu Audio. What's crazier is this brute in ballet shoes produces next to no hiss into sensitive earphones via 4.4mm ... a true feat, barely imaginable, till this point. There is therefore almost no scenario in which you can't enjoy this HA-300 MKII behemoth. Or, employ a different Cayin specialist that you can browse here, and view all our other amplifiers here.

Another Cayin Audio amplifier that lends you multiple variety. This mid-tier EL34 HA-6A with the top-tier sound gets praised by John Grandberg on Darko.Audio for its multiple flavours and way of excelling with all of them. The ability to roll between EL34 and KT88 power tube variants is special in the world of tube headphone amps. With 19 possible options split across HA-6A's driver and power tube permutations, these choices ensure Cayin's versatile champ is a tube roller's delight thanks to an unrivalled ability to customise the final sonics. No other amp let's you swap HA-6A's stock EL34s for Tung-Sol's 6L6GC STR – the "best modern example" of a model Justin Weber has gone on record calling the "greatest American power tube that ever existed".  Even a sonic hybrid between an EL34 and a KT88 surfaces through Genalex's Gold Lion KT77, like Tung Sol's 6L6 made newly under the quality control of New Sensor Corporation. And great driver tubes show up in JJ's ECC802S, long-plates that have been compared favourably to legendary Mullard and Telefunken options. In a direct shoot-out, even without the extra dimension tube rolling grants, one pundit gave HA-6A the upper hand over the previous usual suspect in class, Woo Audio's WA22. [See Product Desc. For More] Depending on your power tube choice, HA-6A has the ability to dump up to 4.5 watts per channel of pure Class A power into your cans, but that's just the beginning of the story. Large EI core output transformers built in-house to Cayin's spec means it's not just brute force but also finesse ensuring great, clean frequency extension at the bass and treble extremes – otherwise a weak point in other tube amplifiers. Meanwhile, a loosely wound EI core power transformer ensures greater AC line performance over a conventional toroid, avoiding saturation plus the negative impacts caused by the latter's high magnetic flux. A choke input in tandem with smoothing capacitors locks stable, quality, DC power for HA-6A in place without sag, post 22DE4 tube rectification. Running EL34s in either triode or ultra-linear mode, or aftermarket KT88s via a switch on the back, yields multiple pairings. Swap to taste, for perfect sound quality with your beloved TOTL headphones from Audio-Technica, Focal, Sennheiser and ZMF Headphones. Equip with an Element series DAC from Matrix Audio for Roon Ready and Tidal streaming. Make the step further up yet with Cayin's flagship HA-300B MKII here, browse the rest of Cayin's gear here, or check out our other amplifier options here.

Stax Audio's premier new hybrid tube/solid-state energiser is an earspeaker lover's heaven. With all the brawn necessary to drive the frightening proposition that is the SR-007 MKII, electrostatic aficionados will nevertheless equally enjoy the subtlety of an output stage fronted by the ubiquitous 6SN7 tube model and its variants. [See Product Desc. For More] SRM-700T takes a step back to allow the music to breathe, in a wide open and airy soundstage even by Stax standards. It's a different sonic outlook to the zealous SRM-T8000 and its vigorous SRM-700S sibling, worth exploring with every earspeaker to appreciate the nuances the oldest electrostatic headphone company can unearth. Also think about building a pseudo-full size earspeaker system with SRM-700T operating as a pure power amplifier. Front your system with Benchmark Media's DAC3 and HPA4 – Head-Fi's most precise pre-amp volume control – for that. While you're reading up, browse all Stax's other offerings here, or our other DAC/amps here.

The little desktop DAC that could. Cayin's iDAC-6II keeps up with the digital times by upgrading its silicone to ESS Sabre ES9028Pro level. This future-proofing meets the decidedly vintage, though. Opt to employ the tube analog output stage Cayin thoughtfully builds in, to enjoy the best of the past and the future. Excellent refinement of the technology at hand saw Headfonics remark on the iDAC-6II's ability to improve almost any system with its clean, sweet presentation. You'll be able to see everything from Cayin here and all our other DAC options here.

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