DAC Audio Decoder Board for Raspberry Pi 3B+/ 4B

This Raspberry Pi DAC Audio Decoder Board supports I2S/DSD/coaxial input, analog/coaxial/optical/I2S output, 384K/32Bit decoding function and unique DSD clock de-jitter.

The audio decoder board supports decoding of I2S and DSD digital audio signals output from the Raspberry Pi motherboard, as well as can decode external coaxial signals by setting the three buttons on the board.

Supporting for 7 kinds of audio outputs like analog audio, coaxial, optical fiber, I2S, etc. The audio output signal of each interface can be independently turned on or off through the button on the board.

The board employs four professional chips. Two groups of LDO are designed to power analog and digital circuits separately. Solid capacitors with large capacity and tantalum capacitors are used for filtering and decoupling to ensure a stable and clean power supply and effectively improve the overall SNR (signal to noise ratio).

PCM9211: TI original professional digital audio transceiver chip, up to 216K sampling rate and ultra-low jitter with coaxial transceiver clock less than 50RMS.

PCM5122: TI original DAC (Digital to Analog Converter) decoder chip, up to 384K/32Bit decoding capability, high SNR (signal to noise ratio) of 112dB and high dynamic range. Richer sounding with more details.

LVDS Output: I2S and DSD output employ DS90LV047A high-speed differential driver chip, supporting transmission rate of 200MHz and ensuring distortion-free I2S/DSD signal.

SiTime Crystal: industrial programmable digital silicon oscillators, with ultra-low jitter and extremely-low phase noise.

I2S/DSD adopts HDMI interface and differential signal output, and a better replay effect can be obtained by connecting common HDMI cable to DAC decoder with I2S input.

Onboard OLED Display, the standby interface can display the current track sampling rate, the current decoder board input signal format, I2S interface output format, etc, more intuitive and more convenient to use.

On the standby or Settings interface, long-press the mode key to enter the following three Settings interfaces successively. On the Settings screen, short-press the mode key to switch select setting item. The selected setting item will blink, at the time press the up or down key to set parameters.

IN: I2S/DSD/SPDIF. Select DAC decoder board 12S, DSD, coaxial three input sources

I2S: 3-L/4-L. Set 3-wire I2S (no MCLK) or 4-wire I2S (with MCLK), Raspberry Pi 2B/3B/3B+ needs to be set to 3-L; Raspberry Pi 4B can be set to 3-L or 4-L(requires MCLK main clock)

MCLK: aut/128/256/512. When the I2S is set to 3-L, set the multiple relationship between the recovery system master clock (MCLK) and sampling rate FS. aut is automatic multiple mode, 256FS for 192K below, 128FS for 192K above.

BIT: 16R/24B/24R/24L/32B. When IN is set to I2S, set the bit depth of I2S input/output, L/R stands for left-justified/right-justified format, and B is standard I2S format. (Note that the input and output formats of I2S are the same)

• 1B When the IN is set to DSD, the bit depth of DSD is 1B and cannot be changed
• 16R/24B/24R/24L When IN is set to SPDIF, set the bit depth and format of I2S output

FLT: 1/2/3/4/5. Set the filter type used internally by the PCM5122DAC decoder chip to switch between different tones

SPDF: out/off. Enable or disable the coaxial output function

RCA: out/off. Enable or disable the analog audio output function

OPT: out/off. Enable or disable the optical fiber output function

I2S: out/off. Enable or disable the I2S or DSD output function of HDMI

Notes:

1.The coaxial interface can be set to either output or input by pressing buttons. You can only choose one.

2.I2S and DSD signals are input from the pins on the Raspberry Pi motherboard. The I2S or DSD signals output by HDMI interface are synchronized with the ones output by Raspberry Pi. PCM9211 chip will de-jitter the DSD clock.

Features

• Support I2S/DSD/coaxial input
• Analog/coaxial/optical/I2S output
• 384K/32Bit decoding function
• Unique DSD clock de-jitter

Applications

Specification

Parts List