Serial to Parallel Shift Register: convert serial data signal to parallel data signal and transmit to DAC circuit.

Digital Audio Bridge: convert DSD to PCM convert all audio signals to left and right channel of 24 Bit/384kHz serial audio data signal.

USB Audio Bridge: receive different audio format from USB, go through high precision signal enhancement, output I2S bit-stream for subsequent processing.

The digital audio section of R01 Audio Motherboard DAC circuitry can be divided into four subsystems: So for a stereo 24Bit R-2R decoder, we need exactly 96 pieces of resistors. To achieve 24bit decoding, we need 48 pieces of resistors (23 x R and 25 x 2R), and that’s good for one channel.

The basic idea of R-2R ladder is a matched pair of two resistors, the first is “R” and the other is “2R”which has twice the value of R. Two headphone outputs, 3.5mm and 4.4mm, are in place so you can connect RU6 to a wide selection of earphone in the market. The hardware volume control buttons are backed by a sophisticated resistor ladder volume circuit, and user can select between Non-Oversampling or Oversampling mode through a simple menu setting. The RU6 Dongle DAC features an in-house developed 24bit Discrete R-2R resistor ladder circuit that can decode up to 384kHz. The bigger difficulties are space and operation limitations but we are confident that R-2R Dongle DAC is technically feasible. By the time we completed R01 Audio Motherboard R&D for N6ii DAP, we noticed the R-2R resistor ladder network can be implemented as low power consumption DAC circuit that offers outstanding audio performance. We have noticed the enormous demand in the Dongle DAC market, but we are not satisfied with the highly integrated off-the-shelf solutions, so we take our time to look for the right technologies.

The RU6 is the first portable USB DAC/Amp from Cayin.

2020 design v9 dongle crack forums