Introduction
The portable audio player market is constantly striving for the pinnacle of sound quality, aiming to replicate the immersive experience of high-end desktop systems in a mobile device. Amidst industry-wide component shifts and the aftermath of events like the AKM factory fire, a new contender has emerged in the DAC chip arena: ROHM Semiconductor. While ROHM has a history in silicon-based IC production, their entry into high-end DACs is a relatively recent and exciting development. The Cayin N8ii was among the first to feature these chips, generating significant buzz. However, iBasso has taken the ROHM implementation even further with the DX320 series, culminating in the powerful DX320Max. Having experienced both the N8ii and iBasso’s offerings, it’s clear that ROHM DACs bring a unique sonic signature to the table. Unlike AKM chips, known for their warmth, and Sabre DACs, often characterized by analytical dryness, ROHM chips strike a compelling balance. They seem to offer the best of both worlds, providing warmth without sacrificing detail and analytical precision without becoming sterile. This makes them exceptionally versatile for a wide range of music genres, from classical and orchestral to EDM and modern pop. Yet, in the world of high-fidelity audio, the DAC chip is just one piece of the puzzle. Amplification, power delivery, and overall system design play crucial roles in the final sound. Achieving true high-fidelity in a portable format requires careful engineering and a commitment to uncompromising audio quality. The iBasso DX320Max aims to deliver just that, promising performance that not only surpasses other portable players but also challenges dedicated desktop setups. Let’s delve into the details to see if it lives up to these lofty claims.
The Chassis: Titanium Craftsmanship
The iBasso DX320Max immediately distinguishes itself with its titanium chassis. While not explicitly named “DX320Max Ti” as it’s the only chassis option available, the use of titanium is a significant design choice. Titanium is an exotic material in consumer electronics, especially compared to more common materials like aluminum and stainless steel. Although abundant as a resource, its complex and costly processing makes it a premium choice. Typically, stainless steel or aluminum are favored for device chassis due to their more manageable production. However, titanium offers a unique combination of strength, lightweight properties, and potential sonic benefits. Different chassis materials can influence the overall sound of a player, and titanium is often associated with enhanced rigidity and resonance control, potentially leading to a cleaner and more detailed sound. The DX320Max is a limited edition device, with only 888 units available worldwide, further emphasizing its exclusivity and premium nature. This contrasts with previous models like the DX300Max, which offered a stainless steel version at a lower price point. With the DX320Max, iBasso has opted for a single, uncompromising titanium construction, signaling its flagship status and commitment to top-tier materials.
Technical Prowess: Under the Hood
The “Max” designation in iBasso’s lineup signifies the pinnacle of their portable audio engineering, representing the flagship of flagships. Following in the footsteps of the DX220Max and DX300Max-Ti, the DX320Max continues this legacy of limited-release, top-tier devices. Each iteration of the Max series has showcased advancements in technology and sound quality. While the DX300Max-Ti was highly regarded, the DX320Max marks a significant shift with its adoption of ROHM DAC chips. For those who appreciate the AKM sound signature, the DX320Max may present a different sonic profile. However, for listeners seeking enhanced fidelity, texture, and high-frequency extension, the ROHM chip implementation in the DX320Max is a compelling upgrade. The core of the DX320Max’s digital audio processing lies in its use of four ROHM BD34301EKV DAC chips. This makes it the first portable player to globally feature a quad ROHM DAC configuration at the time of its release. Each of these flagship chips is designed for stereo processing, handling L+, L-, R+, and R- signals per channel, ensuring true balanced digital signal processing. While a single chip could theoretically suffice for balanced output, iBasso has quadrupled down, employing four chips for even greater performance. This contrasts with the standard DX320, which, while more portable and featuring modular amplifier cards, utilizes a dual DAC configuration. The DX320Max’s quad DAC setup underscores its commitment to pushing the boundaries of portable audio fidelity.
Further enhancing its versatility, the DX320Max incorporates iBasso’s patented MangoOS system, offering users a choice between a dedicated audio-focused OS and a more versatile Android system. This dual OS approach is uncommon in the DAP market due to development complexity and ongoing support costs. However, iBasso provides this option, allowing users to tailor their experience. Complementing the dual OS are two performance modes: Standard and Ultimate. Standard mode utilizes two of the four ROHM DAC chips to optimize battery life, achieving up to 16 hours of playtime. Ultimate mode unleashes the full potential of all four DAC chips for maximum sonic performance, with a battery life of up to 12 hours. The Ultimate mode, being the first and only implementation of a quad ROHM DAC in a portable player, is particularly noteworthy. Implementing four DAC chips is not a simple doubling of components; it requires sophisticated engineering to optimize performance, manage power consumption, and minimize thermal output. iBasso appears to have successfully addressed these challenges, as the DX320Max reportedly generates minimal heat compared to other high-performance players like the Cayin N8ii. For optimal sound quality and to ensure all four DAC chips are properly burned-in, using the Ultimate mode for initial burn-in is recommended.
The ROHM BD34301EKV DAC is a current output converter, a design that presents both advantages and complexities in high-end audio implementation. Maintaining constant current output across varying loads is technically challenging. However, iBasso has seemingly embraced this approach, optimizing the digital-to-analog conversion stage and employing analog gain control with a stepped attenuator. While both the flagship Sony DMP-Z1 and the DX320Max feature pure analog gain and volume attenuation, achieving this accurately requires meticulous tuning of digital conversions, algorithms, and interpolation to ensure the DAC chips operate at their peak performance without introducing undershoot or overshoot artifacts. iBasso has confirmed utilizing innovative implementations in the DX320Max to optimize the ROHM chips, although specific details remain proprietary. Modern DAC chips often offer digital gain and attenuation controls, but these can compromise ultimate audio performance. The DX320Max, like the DMP-Z1, prioritizes pure analog control, marking a significant advancement over previous Max series players that still incorporated digital volume controls. The DX320Max stands as the first Max series player to fully optimize its digital processing unit with quad ROHM DACs and pure analog gain, a notable achievement in such a compact device.
Amplification Technologies: Super Class A and Discrete Design
iBasso’s understanding of the portable audio market and user feedback is evident in the design of the DX320Max. Drawing from market research and customer input, particularly regarding modular designs in flagship players, iBasso has refined its approach to create the DX320Max. While modularity has its proponents and detractors, iBasso has focused on delivering the most optimized tuning and performance in the DX320Max. Despite the rapid pace of iBasso’s product releases, each new device reflects ongoing research, development, and a genuine passion for audio excellence, not solely profit-driven motivations. This dedication is reflected in the DX320Max’s amplification stage.
The DX320Max utilizes a Super Class A amplifier with a discrete architecture. This design aims to eliminate the switching distortions inherent in active transistor amplifiers while retaining the desirable sonic characteristics of traditional Class A amplification, but with minimized heat generation. Furthermore, iBasso has meticulously tuned the analog circuitry, employing a selection of high-grade components, including Tantalum capacitors, polypropylene multilayer film capacitors, and electrolytic capacitors. The DX320Max is notable for incorporating physically large capacitors within its compact form factor, a feat of engineering that surpasses even external portable amplifiers and marks a step up in complexity from the DX300Max-Ti. This dedicated amplification stage is powered by its own independent battery system, consisting of four li-ion packs, effectively making the DX320Max a “two-systems-in-one” device within a single chassis. Similar in concept to the Cayin C9 portable amplifier, which was inspired by the DX220Max, the DX320Max houses both a dedicated balanced amplifier and a dedicated DAC/DAP section, each with its own battery power source and voltage regulation.
With balanced output reaching 9Vrms and single-ended output at 4.5Vrms, the DX320Max delivers power output unrivaled in its size category. This robust power delivery is immediately apparent when pairing the DX320Max with demanding full-size headphones like the Sennheiser HD800S. The resulting audio performance rivals high-end desktop systems, immersing the listener in a level of sonic fidelity typically unattainable from portable devices. While top-tier desktop systems may still hold an edge in certain aspects, the DX320Max redefines the boundaries of portable audio performance. Its ability to drive full-size headphones with such authority leads to the conclusion that the DX320Max is arguably the best portable player for full-size headphones currently available. Experiencing it firsthand is truly the best way to appreciate its capabilities.
The densely packed amplification section, featuring surface-mount components and large capacitors, is a testament to iBasso’s engineering skill. Populating such a complex board requires meticulous hand soldering by highly skilled technicians, a labor-intensive process that contributes to the DX320Max’s premium nature. Automated machine assembly would significantly reduce production costs, but iBasso has prioritized component density and quality over manufacturing expediency. While Astell&Kern has advertised the SP3000 as featuring quad DACs and dedicated amplification, the Max series has consistently incorporated dedicated power sources, voltage rails, and separated channels, with the DX320Max elevating this design philosophy further with its advanced components. A deeper examination reveals iBasso’s commitment to innovation, complexity, and delivering exceptional audio performance at a competitive price point. The engineering within the DX320Max is truly impressive, even to those with extensive technical expertise in audio modification and design. iBasso deserves recognition for achieving this level of sophistication at this price.
Stepped Attenuator and True Line Out
To ensure optimal channel balance, the DX320Max incorporates a custom-designed 24-step stepped attenuator. Unlike resistive strip attenuators, this design utilizes discrete resistors with precise traces and grooves, offering superior reliability and channel balance. While generally robust, stepped attenuators in portable devices can sometimes exhibit minor sound anomalies when the volume knob is turned, as the shaft momentarily lifts before settling into the next step. This is less common in larger desktop stepped attenuators, which are significantly larger in size.
The DX320Max also features a True Line Out mode for both single-ended and balanced connections, accessible through the settings menu. In Line Out mode, the internal amplification stage is completely bypassed, transforming the DX320Max into a high-end digital-to-analog converter source, leveraging its quad ROHM DACs. In this role, the DX320Max performs exceptionally well, delivering a pristine and uncolored audio signal to external amplifiers.
Sound Signature: Neutrality and Musicality
The DX320Max presents a sound signature that is remarkably neutral and natural, yet imbued with musicality, engagement, and a sense of effortless fluidity. It achieves a beautiful balance across the entire frequency spectrum – lows, mids, and highs. Portable players often require sonic compromises, typically sacrificing performance in one frequency range to optimize others, making synergy with headphones a critical consideration. This is less often the case with desktop systems. However, the DX320Max manages to avoid such compromises, delivering balanced performance across the board, a significant achievement for a portable device. It’s important to note that this assessment is relative to other portable devices. When compared to a high-end desktop system using the DX320Max’s excellent line out as a source, the amplifier section of the DX320Max exhibits a slight thinning in the midrange. This subtle characteristic, however, contributes to an even grander soundstage, which is impressive for a portable player.
The DX320Max embodies a personal ideal of sonic perfection, representing a culmination of desired audio characteristics. Its treble is sparkling, smooth, and detailed, with remarkable extension, devoid of harshness or grain. While “perfection” is subjective, the DX320Max-Ti comes remarkably close to this ideal in the realm of portable audio, based on extensive experience with numerous portable systems.
Bass performance is equally impressive, characterized by articulation, control, and well-defined texture. It delivers density and tonal balance with virtually no distortion, exhibiting both dynamic impact and effortless fluidity. Such bass performance is rare, even among desktop audio products, demonstrating a finely tuned balance of qualities.
Mids and vocals are exceptional, with vocals leaning slightly towards analytical and bright, yet remaining captivating. Any further refinement in this area would be a marginal improvement on an already outstanding performance.
Comparing the DX320Max to a reference desktop system, specifically a 300B Western Electric amplifier with Lundahl transformers, reveals that the DX320Max achieves approximately 95% of the desktop system’s performance. The remaining 5% difference lies in the desktop system’s ability to stretch the sonic spectrum wider, offering a slightly broader range of musicality and neutrality. This subtle difference manifests as a very slight thinning in the DX320Max’s midrange. However, the DX320Max transcends typical portable player limitations, venturing into desktop-level performance and surpassing its Max series predecessors. The inclusion of quad ROHM DAC chips is a significant factor in this sonic achievement.
Burn-in and Charging Considerations
Does the DX320Max require burn-in? Yes, despite its impressive out-of-the-box performance, burn-in is recommended to reach its full sonic potential. The burn-in process is generally smooth, with gradual improvements. However, around the 125 to 170-hour mark (approximately 3 days of continuous use), a temporary increase in bass texture and some midrange congestion may be observed. This phase is transient, and performance quickly recovers. It is advisable to avoid continuous 24/7 burn-in. Instead, incorporate rest periods of a couple of hours between burn-in sessions of 8-10 hours each. Using a diverse selection of music genres during burn-in is also recommended.
For charging, the DX320Max offers two options: a dedicated 12V DC input using a 5521 or 5525 plug, and a USB-C port with PD compatibility. When using USB-C, ensure the charger or power bank supports 12V output. Unlike previous Max series players with a wider 12-18V charging range, the DX320Max is specifically designed for 12V charging. Utilizing a PD-triggered 12V power bank offers convenient charging on the go, whether traveling or during outdoor use.
Stock Protective Case and Screen Protector
The included stock protective case is an improvement over previous versions, offering a secure and snug fit. The back of the case features an embedded iBasso logo crafted from steel, enhancing the device’s aesthetic appeal. However, the steel cutout on the back can feel slightly sharp when handling the device.
The DX320Max does not come with a pre-applied screen protector. Interestingly, using tempered glass or plastic film screen protectors can negatively impact touch sensitivity. Therefore, using the device without a screen protector is currently recommended to maintain optimal touch responsiveness.
A Potential Endgame Portable Player
The iBasso DX320Max, as a fully equipped and meticulously engineered player, coupled with its exceptional out-of-the-box performance and user-replaceable battery packs (available through authorized iBasso dealers), positions itself as a potential “endgame” portable player for demanding listeners. Its ability to effortlessly drive full-size headphones like the HD800S solidifies its position as a top-tier device.
Final Verdict
The iBasso DX320Max is a remarkable portable audio player. While physically substantial, its size is a necessary trade-off for the power and performance it delivers, capable of driving demanding headphones like the HD800S with ease. The stepped attenuator, while potentially divisive, is a testament to iBasso’s commitment to audio performance and precise volume control. Its inclusion is a deliberate choice for audiophiles who prioritize sonic fidelity above all else. The DX320Max is a device that will likely remain a benchmark in portable audio for years to come, representing a true “endgame” solution for discerning listeners.
DSD Filter Options
The DX320Max offers DSD filter settings (Low, Mid, High) that subtly affect the DAC chip’s processing during digital-to-analog conversion. These filters, further refined by analog filters in the signal path, allow for subtle sonic tailoring, although the differences are often nuanced.
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Low: This filter setting initiates a more aggressive roll-off of high frequencies, suppressing upper-frequency noise artifacts from sigma-delta processing. This can result in a smoother, more musical sound at the expense of some high-frequency sparkle and sharpness.
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Mid: The Mid setting represents a balanced compromise between noise suppression and high-frequency extension, optimized for typical human hearing bandwidth while still mitigating noise.
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High: The High setting minimizes noise suppression, allowing high-frequency noise to extend up to 56kHz. This setting can potentially offer a more aggressive and detailed sound but with less noise filtering.
Choosing the appropriate DSD filter is largely a matter of personal preference and system synergy. If sibilance or excessive sharpness is present, the Low filter may be beneficial. For those seeking maximum detail and aggression, the High filter may be preferred. The Mid setting provides a well-rounded default option. While the differences are subtle, these filter options offer a degree of sonic customization.
