Sennheiser continue leading the way into 2024 with Momentum True Wireless 4. These sit at the cutting edge of mobile technology, bringing Bluetooth 5.4, Auracast and advanced DSP to bear on top of their TrueResponse® drivers.  But this historic company continue to count on features far before they become mainstream, introducing cutting-edge Bluetooth 5.4 ahead of time so Momentum True Wireless 4 is future-proof ahead of the latest smartphones.  Indeed, it's a lifestyle-enabler and the addition of Bluetooth Auracast means you enter the future world of connectivity with Sennheiser. It gets 5 ⭐ from What Hi-Fi?. Momentum 4 goes right onto Headfonia's Recommended Buys list and gets Gold on Soundnews. Headfonics write it's "almost perfect". StereoNET gives it an Applause Award. The Verge acknowledged MTW4's readiness for tomorrow. Forbes praises a "fabulous job". The advantage afforded by using German-assembled drivers in Sennheiser's headquarters in Wedemark was a first step. But MTW4 steps up above its predecessor and indeed the competition. [See Product Desc. For More] The magic of Auracast, a revolutionary Bluetooth feature that transforms how we experience audio, allows a single device, like your phone or smart television, to broadcast multiple audio streams simultaneously. Momentum True Wireless 4 users within range of the broadcast device can simply choose which stream they want to hear. The possibilities are endless. Powered by Bluetooth Low Energy technology, Auracast is not only versatile but also energy-efficient via Momentum True Wireless 4. It breaks down the walls of individual audio experiences, fostering a more communal and engaging atmosphere.  Sennheiser is here to unmute your world and connect you to sound in a whole new way – audiophile style too. Its advanced TrueResponse® 7mm dynamic drivers gives listeners access to a great bass and treble response, promising to keep you charged during workouts with an upbeat personality and IPX4 water resistance. You're unlikely to want to tweak anything more as you listen in bliss, but Momentum adds control access via Sennheiser's Smart Control App to let you take charge of the way you listen to a greater degree. You'll be able to tailor Transparent Hearing, an ambient mode that lets in the world outside when it needs your attention. Here's proof that Sennheiser's audiophile credentials can be enjoyed by anybody. Revel in their other superbly engineered releases here, or view our other Bluetooth gear here.

Cayin Audio are back with their tiny but mighty, discrete Class A solid-state amplifier that could. iHA-8 returns these tube whizzes to the transistor fold, providing almost 20 watts of Class A power in a compact desktop form factor perfect for any Focal up to HIFIMAN. Don't judge Cayin's solid-state marvel by its size. iHA-8 plays with the same microdynamic, vibrant zeal that charges up notes and brings your music to life, typical of this company's best Class A solid-state work. A 75 watt power supply, discrete FET construction biased into Class A plus optional Hyper Mode's huge operating voltage allows you to throw any low-impedance headphone at it in total confidence. iHA-8's newly-added 4.4mm headphone output adds to the convenience of a member of Cayin's new desktop family together with iDAC-8 and iDAP-8. If you're tempted to plug IEMs in, its resistor ladder electronic volume control control keeps noise low. Indeed, these precise controls preserve signal-to-noise ratio and channel balance down to iHA-8's ALPS-controlled encoder's lowest level – perfect for however much, or little, travel you need. [See Product Desc. For More] 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 powerhouse capable of outputting as much power as iHA-8. Transparent at any volume setting down low as much as up high, with virtually perfect channel-matching, this Cayin behemoth exposes detail buried deep around the noise floor of your music. You'll want to hear it all given iHA-8's linearity – what goes in at the input, comes out amplified the same. To support the signal-to-noise excellence of dual NJR MUSES72320 high-tech volume controls, Cayin resort to the old school of Class A bias, and high operating voltages. The latter can be further boosted to over 30 volts at the push of iHA-8's Hyper Mode button. Already, iHA-8's FET voltage and power amplification brings a tube-like square law function to reduce distortion at the drawing board. Throughout it all, Cayin's individual transistors are kept in their sweet spot and ideal range of operation for best open-loop linearity. They don't rely excessively on the band-aid of negative feedback to correct errors, because there are so few.  In fact, iHA-8 relies on a novel mode of gain control, only adding it as part of the feedback loops sitting around this amplifier's output stage. Excessive open-loop gain is something Cayin absolutely can't be accused off here, allowing you to climb up your volume knob for the best dynamic range performance.  Again, this benefits iHA-8's quiet performance. Cayin's input stage – where the majority of any amp's sonic signature is defined – is built on Toshiba's ubiquitous 2SK209 JFET. Famed for its low noise as a driver, these JFET's serve another purpose: allowing Cayin to direct-couple iHA-8's power stage.  Frequency performance is therefore virtually flat, running 10Hz up to 80Khz and plumbing bass depths so that phase response in the human hearing range is preserved, for fast bass, outstanding dynamics and impactful precision. Meanwhile, high frequencies climb as expected from anything claiming to be high-fidelity. iHA-8's input JFETs run in parallel to output the current needed to drive the large capacitances of Cayin's 24 beastly Vishay MOSFET output devices adequately. The wide bandwidth yielded preserves phase, and adds spatial cues, imaging and treble ambience. iHA-8's abundance of power transistors are mounted on copper bus bars while the chassis gains heat-sinking compared to its predecessor. This heavy hardware allows these MOSFET buffers to keep cool and operate at temperature equilibrium. That way they are able to handle the most current on top of withstanding abundant voltage – useful as Cayin's Hyper Mode comes to mind. The high count of output transistors ensures immense current-handling for good reason, to reap the benefits of a typically-overbuilt Cayin power supply with a 75 watt toroidal transformer at its heart, 50,000 uF of filtering capacitors, ultra-fast recovery rectification and voltage supply regulation throughout – even to iHA-8's power stage. All this leads to Cayin's ultimate voltage source to date – once more capable of the feats of powering ABYSS Headphones' AB1266 Phi TC, Audeze Headphones' LCD-5, Dan Clark Audio plus HIFIMAN's HE-6 and Susvara on a budget. But crucial signal path optimisations mean this brute also wears ballet shoes to elevate any other real-world load. Be it a Fostex, Focal, Final Audio, HEDD Audio or ZMF Headphones, there's nothing iHA-8 cannot tackle ... even IEMs like Subtonic Audio's Storm. Make Cayin the centrepiece of a do-it-all desktop headphone rig feeding it via their own iDAC-8, HIFIMAN's EF500 or Matrix Audio's Mini-I Pro 4. It's that good. If you'd like to explore the tube route, HA-2A awaits you here, as do the rest of Cayin's valve amplifiers here. Otherwise, browse the rest of our desktop amplifiers here.

CMA18 is another milestone for Questyle Audio with the use of ESS Technology's flagship ES9039Pro DAC. CMA18 packs one of the most sophisticated pure Class A analog stages in a DAC available to market now, the strengths of the Hyperstream IV ES9039Pro and CMA18's current-mode amplification working hand in hand. CMA18 is alive with tone colour and saturation, notes propelled forth with a real zeal and macro-dynamic force about them. Questyle's current-mode amplifier is mounted on a high-performance dielectric Rogers board to achieve a 30 per cent reduction in distortion compared to previous flagships, gaining improved dynamics and reduced background noise for a more immersive listening experience. There is a tangible physicality about this Questyle flagship – listeners enjoy a palpable connection hearing familiar music again, as CMA18 heaves and breathes like it were a real, living, being. And still, in a reference DAC where neutrality is so prized, it presents tonal balance accurately. [See Product Desc. For More] In a throwback to Hi-Fi luminary Dan D'Agostino's work [using Texas Instruments] for Krell Industries at the beginning of the 21st century, Questyle designed CMA18's analog circuit path to operate transmitting signal solely in current instead of the standard voltage, starting from its ES9039Pro's analog current output. Manufacturers have long taken advantage of the ESS flagship's claim to be the most sophisticated DAC chip available, outputting in current for best distortion figures before traditionally voicing the circuit through the crucial I/V current-to-voltage converter stage. But D'Agostino understood then that no I/V stage could completely disappear sonically, colouring the sound artificially in ways unacceptable – he therefore removed the stage entirely, by employing Krell's own current-mode analog circuit. Transmission of signal, entirely in current, without prior conversion to voltage, has been revived by Questyle to the same effect here. Removal of the I/V aspect of CMA18's circuit therefore sees the purest expression ever of Questyle's current-mode philosophy, keeping affairs post-digital conversion magnificently and elegantly simple with fewer parts necessary.  Questyle's choice of current-mode signal is the stuff of legend by now. It eliminates the lag time that might otherwise occur when signal is transmitted in voltage, as it builds up at the capacitances in the circuit – current signal passes through unhindered by comparison, with speed and ease.  By doing away with the issue of transmission delay in CMA18, Questyle virtually eliminates any of the harshness caused by the intermodulation distortion associated with high capacitance, solid-state circuits.  Coloured yet correct, CMA18 presents detail smoothly and organically with a sense of vibrancy that's accurate and still entertaining. Another effect of being unhindered by capacitance in the signal path means that huge signal bandwidth is possible, leading to phase response being accurately preserved in the human hearing range. Indeed, to hear current-mode is to hear a naturalness to music not encountered before in a conventional circuit, and Questyle build CMA18 as the ultimate expression to such a topology. It's an implementation that certainly flatters the ES9039Pro – a chip that packs enough computational horsepower to run its 8x oversampling process in just two passes thus minimising rounding errors – an upgrade on its predecessor that used a concatenation of three stacked 2x oversampling passes which compound errors. Not merely an advertisement for Questyle, but for ESS, the ES9039Pro's patented Hyperstream pulse-width modulation technology is a one-up on standard delta-sigma modulation. It now enters its fourth iteration pushing nigh inaudible high-order distortion levels post-conversion further down. This futuristic quad-mono ES9039Pro imparts a digital filter with extremely low in-band ripple and top noise and distortion rejection to allow CMA18 impart a new realism to your music. A 4.4mm headphone output, a pure Class A small signal and power stage, and LDAC Bluetooth input, then allows users to enjoy Questyle's flagship in ever more scenarios. Current-mode will prove even more effective the closer a load is to ground. The results translate to an ultra-low distortion, linear, analog system in tandem with Class A, without resorting to the excessive use of negative feedback. CMA18 works as a perfect DAC for your Hi-Fi system into component input impedances that have been dropping ever more readily since the turn of this decade. Flip CMA18 to variable volume mode, and its analog potentiometer turns it into an excellent pre-amp. Everything above discusses the less-obvious about a true Questyle flagship, because the plain truth is that CMA18 functions as the perfect headphone amplifier first and Hi-Fi hub second. Check out Questyle's other headphone specialties here, or view our other DACs here.

HiBy Music's new Android 12 R4 discrete Class A music player is just such an example, being whatever you want it to be – a pocket rocket compact travel companion or beginner DAP. Stocks arrive mid-May. We've seen this before: just HiBy pushing the boundaries of what's capable at the very top, but also at the bottom. Built on four low-power consumption ESS Technology DACs and two dedicated word clocks, pocket rockets like R4 – at this price – were what Head-Fi used to dream about. Able to decode streams off Spotify, Hi-Res Lossless Apple Music, Tidal and whatever you could download from HiBy's open Android Google Play Store, R4 is an affordable audiophile's dream. That fidelity flows on to be translated into difficult, committed audiophile IEM loads too. Eschewing the de rigueur op-amps that you've gotten blaissé about – the ones that other manufacturers fit even into their mid-tier players – HiBy asks you to choose R4's superior discrete Class A output stage instead. [See Product Desc. For More] For an entry-level player, working with high open-loop performance before feedback is applied is no mean feat ... not to mention being able to handle considerable current and provide actual power into low-impedance IEMs. Distortion always remains low when you're listening, helped by its amplifier's Class A operation. 16 output transistors are fully biased to achieve their most linear open-loop operation, ensuring an accurate reproduction of your music without the excessive use of negative feedback.  This means that the increasingly low impedances of modern IEMs will be dealt with adequately. R4's output devices are truly capable of handling current and outputting up to 525 milliwatts of power – it's not a player that will break composure dealing with loads from Empire Ears and Vision Ears. Picking this HiBy up quickly on the go does not mean sacrificing fidelity. Using op-amps would have been too easy, and HiBy firmly stick by their discrete amplification guns even at R4's price of entry. It's a level of detail that's paid off in natural, accurate sound, reproducing the detail its quad of ESS ES9018C2M DACs are capable of. The attention paid to R4's digital decode extends beyond its DACs, its FPGA and dual crystal oscillators – it's in HiBy's desire to split its quad array of chips into two pairs. One pair decodes PCM, and the other DSD. By recognising the completely different requirements in decoding each format, R4 keeps impressing us below the surface. Specially configuring a pair of its DACs, and their ensuing analog low-pass filters (LPF), means HiBy are in a much better position to bypass DSD's problems and decode the format purely. R4's DSD decode path benefits greatly from its LPF's stronger rejection of ultrasonic noise, in particular preventing single-rate DSD64's noise problems from contaminating the subsequent signal path. HiBy might have gone in all in on the consumer market with R4, but that never stopped these innovators from respecting their audiophile roots. It then backs up that distortion and noise performance with all the luxuries that a modern music lover counts on. Android 12 and Google Play Store's apps run smoothly thanks to a Snapdragon 665 CPU, for up to 11 hours on a single charge. Seasoned audiophiles needing a compact and rugged travel companion will not find themselves missing their reference DAPs very much at all, given how high R4 gets you up the tree in performance. Similarly, newcomers will be treated to the full audio experience very quickly – and in painless financial manner. If you've graduated from R4, be sure to heck out HiBy's other marvels here too, or view all our other music players here.

When one's identity is as rock-solid and well-defined as Vision Ears, you don't change it – you work at bettering it. Such is the case with their VE10 flagship earphone, celebrating 10 years of history through 10 drivers. It's already on Headfonia's Recommended Buys list, and a fitting celebration for Vision Ears to Twister6. The next chapter in the journey of Amin, Marcel & Oliver unfolds with the VE10, maintaining the beloved smooth yet reference tonality cherished by Vision Ears fans. However, this edition introduces the highest level of resolution, presence, and substance ever achieved in a Vision Ears IEM. Crafted as a hybrid 10-driver flagship, the VE10 boasts a CNC-machined housing made of anodised aluminium. This material was chosen to accommodate a sophisticated internal acoustic network, featuring a physical low-pass filter for its 8mm dynamic driver. It shows up in VE10's sound, with a bass that lays down a visceral experience for the foundation of this Vision Ears' down-sloping reference tuning. Handling the mid and high frequencies are nine balanced armatures, including a horn-loaded tweeter that imparts a renewed, vibrant sparkle to the treble, delivering the most apparent resolution in any Vision Ears IEM to date. [See Product Desc. For More] Indeed, embedded within the VE10 is the hallmark of the VE line of earphones: a trusted and true sound embraced by studio professionals, musicians and audiophiles alike. Yet, it never strays into sterility, always providing the immersive experience that the latter crave. The precision remains unwavering in the VE10, even with the introduction of a dynamic driver. While the air's movement adds extra thump to the lows, it crucially maintains the fast, expertly-integrated bass that has long symbolised all Vision Ears monitors. In fact, Vision Ears centre the whole VE10 experience around this driver, marking the debut of a dynamic transducer in a VE series IEM with a physical, robust presence that literally shakes the earth around. Capable of great pistonic excursion, speed and high Q factor, the lessons this new dynamic driver learnt from Elysium and EXT are evident in VE10. The 8mm diameter of the dynamic driver enables it to ascend in frequency without encountering cone or modal break-up, facilitating a seamless handover and crossover to the VE10's nine balanced armatures higher up. Its low-order shallow roll-off means this dynamic driver achieves greater phase coherence than BA alternatives. This handover is aided by an intricate internal structure featuring an acoustic low-pass filter for VE10's dynamic driver. Remaining true to their practice of utilising sound tubes but optimising geometry for minimal turbulence and distortion to rival the best tube-less designs, Vision Ears showcase their pedigree with the abundance of drivers akin to a mini-choir producing the tonal density they've made their own. The incorporation of a horn for the VE10's tweeter is a novel implementation of a classic approach. Placing this acoustic amplifier at the output serves to boost the SPL from a balanced armature that moves relatively little air. This design choice ensures that the VE10 doesn't excessively strain its tweeter for volume, operating it in a cleaner and more elegant manner. Rather than succumbing to an exuberance of new technology, Vision Ears adheres to their established sound. VE10 employs these tools as mere aids to create VE's most articulate release to date, but as means to an end, rather than the end itself. The VE10 embodies the ethos of hard work and innovation that defines Vision Ears, making a clear statement that they are here to stay. It positions itself as a testament to enduring quality, laying the foundation for another successful decade. Check out the road that Vision Ears took to the VE10 here, or view our other IEMs 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. Dual AKM AK4493SEQ DACs help bring N3 Ultra's concept into the future. Its tubes then sweeten Cayin's decoded analog. But, 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.

Embracing a philosophy of continual progress and innovation, DITA Audio presents its inaugural resin-based hybrid earphone titled Project M. The Project M departs from DITA's previous designs with a redesigned, ergonomic form that strikes a balance between familiarity and distinctiveness, embodying a new era for the brand. Equipped with DITA's revolutionary PM1+ Dynamic Driver and a balanced armature driver, the Project M showcases the prowess of the PM1+ Driver – a 9.8mm dynamic driver exclusively crafted for this model. Serving as the sonic heart of the Project M, the PM1+ Driver imparts the earphones with a signature characterised by texture, clarity, speed, and punchy bass, delivering a full-range sound experience. [See Product Desc. For More] To further enhance the audio landscape, the Project M integrates a single Knowles balanced armature Driver alongside the PM1+ Driver, both housed within a meticulously optimised stainless-steel chamber. Project M does not run contrary to DITA's belief in the use of single-dynamic drivers. This mini-marvel's dynamic driver still operates full-range, with its balanced armature counterpart only picking up where it's been assigned, contributing further in the high-frequencies. The sound produced by the Project M emanates through a custom-molded transfer tube terminating in an aluminum nozzle, maintaining DITA's tradition of tailoring cables for each earphone. Its MOCCA cable, featuring conductors by Cardas from the USA, consists of 16 strands twisted to DITA's specifications and jacketed in a flexible PVC outer layer. MOCCA is future-proofed with DITA's APV2 technology, ensuring compatibility with evolving audio setups. Leveraging Acoustic FEA, objective tests, and subjective listening experiences, the sound tube profile is finely tuned for the Project M's dynamic driver, delivering a coherent, full-range experience reminiscent of 2-channel systems. Encased in a slow-pour transparent resin mix, the entire assembly results in an earpiece with an elegant and captivating visual appeal—distinctive hallmarks of a DITA product now positioned in a new price range. Adhering to the Project M's minimalist industrial aesthetics, each unit is accompanied by a Systainer case, crafted by Tanos exclusively for DITA Audio. The Tanos case includes custom-made silicone inserts to safeguard your contents during everyday life. Owners can choose to freely remove the top and bottom linings, which are moulded to fit the case with the addition of double-sided tape for extra security, easily removable at the user's discretion. Check out DITA's other human-first products here, or browse our other IEMs here.

A showcase of the value and performance of HIFIMAN's Himalaya LE DAC technology, the network-enabled R2R EF500 is another Everest of achievement. This streaming DAC/amp is exactly the kind of statement HIFIMAN chase – these planar-magnetic headphone extraordinaire's spirit for innovation is what spurred them to develop EF500. Taking the company's discrete new R2R Himalaya LE DAC and slapping on a 4.4 watt per channel amplifier, EF500 is HIFIMAN's claim that they are all you'll need to run a complete personal audio chain on your desktop. With an added ethernet input, you gain the ability to leash EF500 straight to your network router and enjoy music off your NAS, or favourite Android or iOS streaming app. A fully-balanced, differential DAC/amp through the signal path from decoding to amplification and output, EF500 counts on common-mode rejection to achieve excellent noise performance and combine resolution with R2R's lauded musicality. [See Product Desc. For More] HIFIMAN's diminutive powerhouse is a statement of technological ambition from China's leading headphone manufacturers, changing the game by equipping all levels of Head-Fi with an extremely capable source. That's double the feat because the precision demanded in exact resistor values – for the buttery, natural and resolving ability that R2R DAC topology is known for – goes up. For an entirely different sound otherwise, EF500's grants users the 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, claiming over 115dB of signal-to-noise ratio. That's signal that sees EF500 output in fixed voltage via line XLRs and RCAs, in the sense of a conventional DAC. But HIFIMAN – famous for its immensely challenging Susvara and HE6 – challenge you to bring its balanced headphone outputs to bear. A balanced, differential Class A/B amplifier swings plenty of signal voltage and backs that signal up with a power stage bristling with current, to claim a mighty 4.5 watts of power. All so you can enjoy the benefits of EF500's network capability with nigh any flagship transducer. That's power beyond measure but HIFIMAN says it's always better to have more than you need. So EF500 can go about driving the likes of their headphones, plus any HEDDphone 2, Sennheiser or ZMF Headphones, with tons of headroom, and no worry at all. Throw any headphone at EF500: you won't regret it. Also, view our other offerings from HIFIMAN here, or our other amplifiers here.

Since this is limited, move for it quickly. Arguably the best-rounded of Effect Audio's Code series, Code 24C's ability to make neutrality sound spectacular, immersive and liquid is rare in the world of cables. Headfonia help place this build in the wider context of the manufacturer's recent release. This certainly isn't your ordinary Effect Audio cable. The Code 24C is the descendant of their flagship Code 23, inheriting its legacy and pushing it further. Code 24C features a new and ergonomic Trio-Flex™ Pure Solid Core System, with 17 multi-sized core bundles for a smaller profile (18.5 AWG). Don't be fooled by its size, though. The Code 24C is a vocal powerhouse, delivering clear highs and impressive sub-bass that rivals the deepest lows of its predecessor. This cable is a testament to the 15 years of cable-making expertise at Effect Audio. It's a bold iteration, built for those who crave an uncompromised listening experience. Check out the rest of Effect Audio's cables here, or view our other options here.

HiBy Music have nothing more to prove in the hand, so they've turned their attention to the desk. FD5 is the answer to the question Head-Fi had – can HiBy build a DAC/amp leashed to a wall power supply that could match, or even exceed, their portable music players? FD5 says they can. Built with a quad of AKM's AK4493SEQs supported by a FPGA, the discrete Class A FD5 is everyone's affordable compact gateway into an over-performing one-box desktop solution. [See Product Desc. For More] HiBy's first DAC/amp is not without flagship genes either – it borrows its analog stage from its R8II statement DAP.  With such a discrete output stage HiBy immediately takes a big step ahead of the chasing pack of pedestrian op-amp competitors. Its individual transistors provide the power necessary to push big HIFIMANs and Rosson Audio Designs – not to mention Subtonic Audio's Storm and Symphonium Audio's Crimson – on a budget. The ability of discrete output devices to handle current and push power is a given, and a necessary HiBy trademark given FD5's power supply sporting several thousand microfarads of filtering capacitors. It's a powerhouse that's escaped the pocket and now has the stage, and the limelight.  When you're done with FD5 at the desk move onto HiBy's portable DAPs here, or explore other desktop DAC/amp upgrades here.

Immerse yourself in the unparalleled sonic precision of the Cadenza 4. Letshuoer's proprietary 10mm dual-chambered beryllium coated dynamic driver is the heart of the experience. This innovative driver is both incredibly light and extremely rigid, creating a foundation for unmatched sound reproduction. Cadenza 4 elevate this performance with a combination of Knowles and Sonion balanced armature drivers. This powerhouse combination delivers rich mid-frequency details, ample treble extension, and resolution that reminds of Cadenza 12. [See Product Desc. For More] But the magic doesn't stop at the drivers. The Cadenza 4 features a three-tube acoustic design with a meticulously engineered, four-way electronic crossover. Letshuoer haven't forgotten about comfort either. Through collaboration with Heygear Technology, they've refined Cadenza 4's chassis for a secure, comfortable fit that allows you to lose yourself in the music for hours on end. The matte-finished CNC aluminum alloy housing not only looks stunning but is also incredibly durable, ensuring your Cadenza4 will be your trusted companion for years to come. The final touch? A luxuriously crafted cable featuring 392 strands of high-purity silver-plated monocrystalline copper. This premium cable not only enhances the fidelity of your audio but also boasts three types of interchangeable 3.5mm, balanced 2.5mm and 4.4mm plugs for seamless compatibility with all your devices. Explore how Letshuoer are redefining the budget category with their other IEMs here, or view our entire catalogue here.

Bose promise a revolutionary audio experience with their Ultra Open Earbuds. These innovative earbuds break the mould by letting you stay connected to your surroundings while still enjoying immersive music. Ultra Open Earbuds' unique cuff-shaped design is both stylish and comfortable, allowing for all-day wear without sacrificing awareness. CNET send their approval.Want to open your world and horizons while still listening to awesome tunes? Ultra Open Earbuds make it possible. Gone are the days of bulky headphones or uncomfortable in-ear buds. [See Product Desc. For More] Bose's latest innovation features a sleek design with soft edges and a metallic finish, blending seamlessly into your personal style. They're also designed to work with glasses, hats, and jewelry without interfering. But style isn't everything. Bose has engineered the Ultra Open Earbuds for superior comfort and stability. A special flex arm, coated in soft silicone, connects the speaker to the battery barrel, resting gently against your skin. Bose's light-as-air grip ensures the earbuds stay secure on almost any ear shape. The magic behind the Ultra Open Earbuds lies in Bose's proprietary OpenAudio technology. Their innovative system combines a powerful transducer with a precisely controlled acoustic structure to deliver clear, high-quality audio directly to your ears. Remarkably, there's minimal sound leakage, ensuring only you enjoy the full richness of your music. For an even deeper listening experience, the Ultra Open Earbuds feature Bose Immersive Audio. This technology uses digital signal processing and an onboard motion sensor to create a wider, more spacious soundstage. It's like having your own private concert, with instruments positioned realistically around you. Whether you're relaxing at home or on the go, Bose Immersive Audio brings your music to life. Indeed, Ultra Open Earbuds offer two listening modes for Bose Immersive Audio: 'Still' and 'Motion'. 'Still' mode is ideal for stationary listening, keeping the audio fixed in a specific position. 'Motion' adjusts the audio as you move, ensuring you stay immersed in your music even while walking or running. But if noise-cancelling and isolation are called for, check out Bose's Ultra Earbuds QuietComfort Ultra Earbuds here, view the rest of their selection here, or our other Bluetooth devices here.

After the world of planar-magnetic flagships was reinvigorated through acoustic tweaks and tricks in 2022 and 2023, Final Audio have joined the fray in 2024 with their own D7000 headphone. A departure from the double-sided magnet structure of its D8000 peer, D7000 counts on its single-sided planar-magnetic driver to do the work of two and potentially surpass previous results. Its new Pinna-Align Diffuser technology makes its Final debut ear-side, working hand in hand with Air Film Damping System (AFDS) to raise their co-flagship’s game. [See Product Desc. For More] D7000's Pinna-Align Diffuser works in tandem with AFDS to allow Final to maintain the open and spacious sound signature that is a hallmark of their planar magnetic headphones, while simultaneously delivering the rich, impactful bass that listeners crave. With many recent flagships lauded for the accuracy of their frequency response through the vital mid-range and upper mid-range, Final have now issued their own answer with D7000 – their Pinna-Align Diffuser goes further by strategically controlling the space through which sound travels.  This allows for precise control over the time it takes for sound waves to reach each ear, ultimately creating a more immersive and realistic three-dimensional listening experience. No Fazors or metamaterials for Final – a company with extensive experience crafting over-ear headphones. This historic Japanese company have brought their resources to bear in understanding how individual ear shapes can significantly impact listening experiences. Together with AFDS and the pistonic motion it promotes of D7000’s planar diaphragm, Final’s new release is set to leave a mark as great as its D8000 counterpart. AFDS effectively eliminates the need for restrictive design elements like tightly sealed earpads, which can negatively impact soundstage and overall audio fidelity. The D7000 represents a significant leap forward in headphone design for Final. By meticulously revising the shape of the diaphragm's coil and punched metal, Final has achieved a breakthrough: more effective diaphragm control. Traditionally, planar magnetic headphones risked diaphragm collision with the magnet at high volumes, particularly in the low-frequency range. This could distort the sound and limit the perceived depth and naturalness of bass. But a metal perforated plate inserted between the magnet and the diaphragm sees the internal airflow of the unit operation damp unwanted movement perfectly in Final's case.  This innovation is made possible by the high-precision machining of the D7000's aluminum-magnesium alloy housing, manufactured at Final's headquarters in Kawasaki, Japan. Leveraging their vast ear data database and a dedicated listening room within their factory, Final's engineers have conducted extensive research and testing to release Pinna-Align Diffuser together with AFDS. Together, they ensure repeatable frequency and phase results regardless of the anatomy of different listeners' ears. Needing no introduction, and having achieved rave reviews on D8000, Final's advanced AFDS system eliminates diaphragm-magnet contact, achieving both deep, impactful bass and delicate high frequencies. While both closed-back and open-back headphones typically rely on sealed earpads to artificially extend their low-frequency response, this approach often compromises the natural spaciousness of the sound source. To achieve both deep, rich bass and accurate soundstage, Final prioritises the driver unit's ability to reproduce low frequencies inherently. This is crucial, as conventional planar magnetic and dynamic headphones frequently struggle with either limited low-frequency extension or the requirement for tightly sealed earpads, which can negatively impact sound quality. Final's D7000 therefore transcends the limitations of traditional planar magnetic types, offering the coveted openness of dynamic headphones without sacrificing low-frequency power. The innovative AFDS empowers the driver unit to reproduce a wider low-frequency range without relying on totally sealed earpads that curtail staging. Final's revolutionary technology allows D7000 to achieve exceptional low-frequency response while maintaining the open and airy sound signature characteristic of the D series. Furthermore, the D7000 prioritises comfort and durability. Final's streamlined design, after removing a whole magnet array, is 16 per cent lighter than D8000. Combined with breathable, Japanese paper earpads that are a new development for the D series, their unique construction of breathable foam and special fibres achieve superior sound quality reminiscent of the limited D8000 Pro flagship Final once released. D7000 could certainly make a fine introduction to Final's flagship line, or serve as a complement to the existing D8000 owner. Check out their Bluetooth line-up that let's you take Final's famed sound quality on the road with you here, or view our other headphones here.

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 RCA outputs – 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 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. 

The winning combination. The Combine from Nobunaga Labs is a first, basic hybrid cable mixing pure copper and silver straight-up.  Beyond the materials, this Nobunaga entry cable really sits at a sweet spot as it combines the V-shaped natures of its Inspire and Supreme siblings.  Without being as over-bearing as Inspire's energetic and zealous emphasis, Nobunaga invite you to bask in the gentle benefits this bargain yields with your IEMs. Combine's sweetness and sophistication never become as diffuse as Supreme though, allowing it to occupy its own special place in Nobunaga's line perfectly. Apply its traits to IEMs that perhaps risk being too strident in the upper-midrange with vocals or guitars. Combine will immediately yield more space, blackness of background and perceived dynamic range.  Apply Nobunaga's latest cost-effective star to IEMs many more times its price, indeed. Also explore their vast myriad of other sound signatures here, or check out our other cables 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. Flexibility might be the first topic discussed with the lightweight and compact HA-2A, but compromise in quality was never an option. 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. [See Product Desc. For More] 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.

Unveiling the GO bar Kensei, iFi Audio's aim for portable audio perfection. Experience the world's first portable DAC with K2HD technology, co-developed by legendary Japanese engineers. This revolutionary tech breathes new life into your music, restoring the warmth and detail lost in digital conversion. Combined with its ultra-portable design and powerful amplification, iFi's Kensei elevates your listening experience anywhere, anytime. It's audiophile-grade sound on-the-go, transforming your commute, workday, or travels into a personal concert. Check out the rest of iFi's gear here, or view our other portable DAC/amps here.

Yamaha makes a glorified return to its Hi-Fi past in its planar-magnetic flagship headphone YH-5000SE. This is bound to make an impact – figuratively but especially literally. Yamaha received full marks from What Hi-Fi? and SoundStage! Solo. Hyper-dynamic, the punch this pair produces is unrivalled in all of Head-Fi, not matched for sheer impact by comers from all topologies – be it fellow planar, dynamic, AMT or electrostatic drivers. With a tuning popularised in Japan, the featherweight YH-5000SE is a heavyweight that shows its roots in hitting hard and fast while gracefully accommodating the hot and loudly-recorded female vocals typical of Asian acts.  Lovers of Chinese, Japanese, Korean and Cantonese pop will find that this Yamaha is not stuffy nor stuck in the past, coming right out of the blocks by producing every detail in the voice and dodging potential for harshness. A natural progression from Audio-Technica's ATH-ADX5000 and Focal's Clear MG, YH-5000SE similarly propping that soulfulness up with bass impact and depth for days for concert-like atmospherics. [See Product Desc. For More] Inspired by Yamaha's first planar "orthodynamic" headphone of the 1970s but not merely content to reproduce it, YH-5000SE pursues an expressive contrast between stillness and motion, achieving low-frequency reproduction with rich volume and extraordinary transparency. The result is that the full dynamism of the sound is artistically conveyed and immerses the listener inside a remarkable, musical world. YH-5000SE's specially developed thin-film diaphragm is the result of relentless prototyping, meticulous measurements, and rigorous analysis. Yamaha manufactured it by etching the voice coil with a unique pattern on both sides of the film and applying minute corrugation. Moreover, highly permeable, micro-perforation air dampers are arranged on both sides to ensure the diaphragm motion can be accurately controlled for sound reproduction that doesn’t degrade the vibrant dynamism of the music. YH-5000SE's rounded shape devoid of any fixed points other than the outer circumference maintains uninhibited movement of the entire film, enabling exceptionally full, yet clear low-frequency expression. Yamaha's housing is built without any fixed central structure ensuring shape retention by use of concentric circle corrugation and pattern reinforcement, and avoiding magnetic substances in the vicinity. Indeed, YH-5000SE's large housing has ample internal acoustic volume and reduces the adverse effects on the thin planar diaphragm, preventing sound reflections inside the rear cavity to eliminate undesirable resonance.  Yamaha adopted a newly developed, Japanese-made, rolled plain Dutch weave stainless steel filter to control internal pressure in the housing. It includes an arch-shaped protrusion arranged inside the housing which functions as a reflector. Produced under strict air permeability control, this filter enables smooth air discharge and is the key element in creating the sound field expression we aspired to for the YH-5000SE. These features allowed Yamaha to achieve exceptionally controlled reproduction of both instruments and vocals, and properly control those sounds throughout their initial attack and final decay. This package is complete with two different types of earpads. A hybrid version combines leather around the build with well-ventilated mesh on the inner circumference that increases the perception of dynamics. Meanwhile, the alternative utilises Toray Ultrasuede to blend frequencies better bottom to top for an even longer immersive experience with soft, warm sound. A 4.4mm silver-plated copper cable comes included for all your balanced amplifier needs. Take advantage of YH-5000SE's flat impedance together with Enleum's current-source HPA-23RM, or Cayin Audio's transformer-output tube amplifiers. Questyle Audio's CMA18P and CMA18 Master are solid-state candidates, as is Cayin's iHA-8.  At the end of the day, the solution could very well lie in house with Yamaha's own HA-L7A DAC/amp. Check out the rest of their releases here, or view our other headphones here.

There is always something futuristic about R2R, but the network-enabled EF499 ascends to another level. This streaming DAC/amp is exactly the kind of achievement HIFIMAN are typical of – these planar-magnetic headphone extraordinaire's spirit for innovation is what spurred them to develop EF499. Taking the company's discrete R2R Himalaya DAC and slapping on a 4.4 watt per channel amplifier, EF499 is HIFIMAN's claim that they are all you'll need to run a complete personal audio chain on your desktop. With an added ethernet input, you gain the ability to leash EF499 straight to your network router and enjoy music off your NAS, or favourite Android or iOS streaming app. Disregarding its entry-level standing, HIFIMAN's diminutive powerhouse is a statement of technological ambition from China's leading headphone manufacturers, changing the game by equipping all levels of Head-Fi with an extremely capable source. [See Product Desc. For More] That's double the feat because the precision demanded in exact resistor values – for the buttery, natural and resolving ability that R2R DAC topology is known for – goes up. For an entirely different sound otherwise, EF499's grants users the ability to switch from NOS to oversampling mode, for the cleanest possible result.  That's signal that sees EF499 output in fixed voltage via line XLRs and RCAs, in the sense of a conventional DAC. But HIFIMAN – famous for its immensely challenging Susvara and HE6 – challenge you to bring its balanced headphone outputs to bear. A Class A/B amplifier swings plenty of signal voltage and backs that signal up with a power stage bristling with current, to claim a mighty 4.4 watts of power. All so you can enjoy the benefits of EF499's network capability with nigh any flagship transducer. That's power beyond measure but HIFIMAN says it's always better to have more than you need. So EF499 can go about driving the likes of their headphones, plus any HEDDphone 2, Sennheiser or ZMF Headphones, with tons of headroom, and no worry at all. Throw any headphone at EF499: you won't regret it. Also, view our other offerings from HIFIMAN here, or our other 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. Twister6 praises PB5's "analog texture with bigger soundstage expansion" before becoming a dynamic duo with D16. 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.