The iBasso D17 Atheris Fuses Discrete R2R Ultra and 1-bit DACs with Dual Korg Nutube Amplification, Delivering a Rich, Lifelike Sound and Desktop Power in a Portable Form In-house developed R2R Ultra + 1bit dual discrete DAC & tube amp Four-channel fully balanced symmetric R2R architecture Features dual Korg 6PI Nutubes FPGA-Master 3.0 ensures nanosecond-level I/O precision Delicate sound with a natural analog presentation Bloom's Take The iBasso D17 Atheris brings flagship-level sound to a transportable form, blending R-2R, 1-bit, and tube technologies inside a rugged, minimalist chassis. With two control knobs, a monochrome OLED, and a hybrid amp stage, it focuses on pure performance and sonic versatility rather than flashy design. It’s not exactly pocket-sized, but it’s built for those who want desktop-grade audio anywhere. The D17’s three processing modes—NOS, OS, and SD—let listeners tailor their sound: R-2R offers a smooth, analog warmth, while 1-bit mode delivers sharper clarity and micro-detail, balanced beautifully by the tube stage’s natural richness. It runs quiet enough for sensitive IEMs yet powerful enough for demanding headphones, offering excellent control and dynamics across setups. Designed to blur the line between portable and desktop, the D17 Atheris succeeds in delivering serious, high-end performance on the go, making it one of iBasso’s most impressive and flexible DAC/amps yet. Read our full review. A New Benchmark for Portable DAC/Amp's The D17 utilizes iBasso's in-house developed discrete R2R Ultra and 1bit DAC. It features a four-channel fully balanced symmetrical R2R discrete component DAC, utilizing a total of 284 high-precision film resistors with an accuracy of 0.01%. The R2R decoding provides a natural, delicate sound with a natural analog presentation, offering a unique lively listening experience. The in-house developed 1bit DAC employs 8 sets of 8E, totaling 64 PWM-DACs, delivering a landscape of rich musical details and extremely high resolution audio playback. D17 Has Three DAC Modes NOS Mode（PCM utilizes R2R DAC decoding, DSD utilizes 1bit DAC decoding）All to R2R（OS mode，all to PCM format）All to 1bit（SD mode，all to DSD format） Four-Channel Fully Balanced R2R Architecture The D17 employs a four-channel fully balanced R2R architecture built around 284 ultra-precise resistors, paired with iBasso’s custom hardware and software compensation for exceptional accuracy. This design achieves an impressive -104 dB THD+N, over 10 dB better than many mainstream R2R DACs, while delivering the warm, detailed, and naturally musical sound signature enthusiasts love. R2R Ultra R2R Ultra is iBasso’s next-generation R2R architecture, designed to solve the core limitations of traditional R2R DACs. The D17 uses a 24-bit, fully balanced 8-channel R2R array combined with a 4-bit MSB String DAC, a self-developed FPGA algorithm, and a hardware resistor compensation network. This differential, multi-DAC design fundamentally eliminates zero-crossing distortion while delivering far higher linearity than conventional R2R implementations. With 436 high-precision resistors working in tandem with real-time FPGA calibration, R2R Ultra achieves exceptional measured performance—up to 126dB dynamic range and THD+N as low as –104dB. The result is a cleaner, more stable, and more accurate R2R decoding system that represents a true generational leap beyond traditional R2R designs. Dual Korg 6PI Nutubes The two Nutube 6P1 tubes on the D17 impart a unique tube character and a warm, mellow yet dynamic texture to the sound. The anode is powered by a 24V high-voltage supply, providing better linearity. Paired with the high-performance TI buffer amplifier BUF634A, it ensures a steady and powerful source of power. As a result, the D17 can deliver over 1200mW + 1200mW at 32Ω, easily driving a wide range of flagship IEMs and high-impedance headphones. Opening the Door to Acoustical Realism In 1bit mode, the four channels L+, L-, R+, and R- each have 16E, totaling 64 PWM-DAC units working together. Controlled by the FPGA-Master 3.0 with nanosecond-level precise I/O delay management while compensating for "wiring delay" to ensure that the signal edges arriving at the DAC are aligned and strictly synchronized. This not only achieves an impressive THD+N of -114dB but also significantly enhances sound detail and density. Three-Layer Composite Seismic Isolation System The D17’s three-layer composite isolation system combines double-layer PCBs and damping materials to disperse stress, cut resonance, and keep microphonic effects below audible levels, placing it at the forefront of iBasso’s tube amp designs Dual Battery Architecture With separate batteries powering the DAC and headphone amp, the D17’s dual architecture isolates digital interference and maintains stable current even under heavy loads, delivering clear, distortion-free sound with exceptional musicality. FPGA-Master 3.0 The D17 is equipped with iBasso's in-house developed FPGA-Master 3.0 architecture, deeply integrated with two Accusilicon ultra-low phase noise femtosecond oscillators to create a pure, unified single clock source. Through nanosecond-level high-precision delay control and real-time clock regeneration technology, the system can simultaneously compensate for R2R decoding and 1bit decoding, reducing clock jitter and distortion to extremely low levels. Analog + Digital Volume Controls The D17 combines a compact 24-position stepped attenuator with ultra-precise ±0.1dB channel matching and DSP-based digital control, delivering exceptionally accurate and flexible volume adjustment Cutting Edge Parts Loaded with cutting-edge components, the iBasso D17 Atheris packs 284 ultra-precise 0.01% film resistors, dual 30,000-hour Nutube 6P1 vacuum tubes, and a custom 24-position stepped attenuator with ±0.1 dB channel accuracy. Twin Accusilicon femtosecond oscillators, a pro-grade DSP with 192 dB dynamic range, and an ultra-low-noise 0.6 μV power supply deliver breathtaking clarity, while dual batteries, iBasso film and vintage SPRAGUE capacitors, and a sharp 1.3-inch OLED display round out a portable DAC/amp built for uncompromising performance.
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