IBASSO D17 ATHERIS Headphone Amplifier DAC

iBasso D17 Atheris: R2R/1-bit conversion

The D17 Atheris adopts a differentiated conversion architecture, isolating PCM and DSD stream processing to avoid any intermediate conversion. For PCM signals, it uses a discrete R2R network comprising 284 resistors paired to within 0.01% and distributed across four symmetrical channels. This precision pairing guarantees the linearity of the voltage steps and achieves a THD+N of –104dB. This approach favours direct conversion by analogue weighting, reducing quantisation errors and ensuring stable reproduction across the entire dynamic range.

At the same time, DSD streams are handled by a 1-bit architecture based on 64 PWM DAC cells organised into eight independent groups. This parallelisation smooths modulation noise while increasing instantaneous processing capacity. The system thus achieves a THD+N measured at –114dB. This strict separation of conversion paths allows each format to be exploited according to its native structure, without any algorithmic compromise between PCM and DSD.

iBasso D17 Atheris: Reduction of microphonic effects

The internal structure is based on a double-layer PCB combined with integrated damping materials. This composite construction increases mechanical rigidity while dispersing vibration stresses. Beyond simple structural strength, this approach limits the transmission of vibrations to the tubes, thereby reducing the microphonic phenomena inherent in the amplification architecture used.

iBasso D17 Atheris: Analogue and digital volume control

Volume management is based on a dual complementary approach. The analogue section is handled by a 24-position, four-section mechanical attenuator developed in-house, guaranteeing a maximum deviation of ±0.1dB between the left and right channels.

At the same time, digital processing relies on a professional DSP that allows for precise signal adjustment prior to conversion. This analogue/digital combination enables fine tuning to the headphones used while preserving the effective resolution of the signal. This control architecture thus maintains tonal consistency and spatial accuracy across the entire volume range.