Audiophile, High Quality T-DAC, RPi-DAC

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Overview Schematics RPi-DAC-RCA+ Raspberry-Pi RPi-DAC-Dual RPi-DAC-SPS RPi-DAC-SPDIF RPi-DAC-FPGA RPi-DAC-IF Home

RPi-DAC-RCA or RPi-DAC - how to get it?

  • Please order here: Gravitech US or Gravitech Thailand
  • The RPi-DAC-RCA is branded as: Durio Sound.
  • The project is completed - I am working on new projects (IoT, IoE and BLE related).
  • All pictures shown here are my own setups. Durio Sound can look differently.
RPi-DAC SingleStereo

RPi-DAC SingleStereo with AC-DC rectification onboard (just AC transformer needed)

RPi-DAC SingleStero

RPi-DAC SingleStereo board


RPi-DAC SingleStereo components with RPi-DAC-SPS (w/o AC-DC rectification)


RPi-DAC SingleStereo assembled (stacked), with RPi-DAC-SPS


RPi-DAC DualMono with RPi-DAC-SPS, RPi-DAC-FPGA and alternative RPi-DAC-SPDIF (substitutes RPi)


RPi-DAC SingleStereo with RPi-DAC-IF for RCA or as alternative SPDIF, USB, TOSLINK and XLR connectors (needs RPi-DAC-FPGA)

PCB Solder Options

The RPi-DAC PCB can be equipped (soldered) with different combinations of parts

  • complete: DAC, LDOs, OpAmps, headphone amp, rectifiers, electrolyte caps - used to connect just AC transformer
  • no rectifiers and no electrolyte caps - used with RPi-SPS or with DC inputs
  • no headphone amp - breakout wires for final stage (symetrical after OpAmp)
  • no OpAmp and no headphone amp - use your own I/V converter, just DAC and LDOs
  • no LDOs - bypass LDOs and provide required voltages from your DC supplies
    helpful if you might be scared to solder the LDOs manually
  • optimize blocking capacitors - not all needed or mix different types and size in order to compensate parasitic inductances
  • with 24.576MHz XTAL - if used on FPGAs and other boards as clock source, not needed for RPi

RPi-DAC Kit Options

The RPi-DAC can be combined with several other modules in a flexible way:

  • with RPi as network player or with Volumio
  • with XMOS eval board (or any other USB-to-I2S) as USB sound card
  • with RPi-SPDIF as S/PDIF, TOSLINK or (with XMOS module) as sound card
  • with RPi-DAC-IF as interface module for an enclosure (with S/PDIF, TOSLINK, USB, optional Bluetooth)
  • with RPi-DAC-FPGA module for upsampling, filtering or rotary encoder volume control
T-DAC Module System
T-DAC module system
T-DAC Configurations
RPi-DAC options

Downloadable files and projects

You can download here ZIP archives related to the T-DAC and RPi-DAC,
e.g. ExpressPCB project files, Xilinx FPGA ISE [3] project to use PCM1794A [1] DAC board on a XynergyXS FPGA board [2]etc.

I cannot offer here a complete Linux kernel or image for the Raspberry Pi (with I2S support), I am sorry. Please see the steps on the

I will publish revision 3 PCB related information asap. Please find here revision 1 related information as a fist glance.

RPi-DAC site how to modify the Rasbian Linux kernel or please use other sources in order to use I2S and ALSA on Raspberry Pi.


  • cost-effective and feature rich alternative for HifiBerry
  • have options to separate power for DAC from RPi, to power RPi
  • keep the P1 connector on RPi free

Download (35KB) - rev.2 new

Download PRi-DAC-RCA_overview.pdf (109KB) new

Download BOM_PRi-DAC-RCA.pdf (79KB) new

T-DAC ExpressPCB

  • ExpressPCB project file for the generic T-DAC module (not RPi-DAC)
  • It uses through-hole electrolyte capacitors for the DC rectifiers
  • standard ExpressPCB format (a bit larger as RPi-DAC), Dual-Layer, with almost all components as SMD components (0603, 1206)

Download (69KB)

RPi-DAC ExpressPCB

  • Similar schematic, just optimized form factor for Raspberry Pi - same size, directly stackable
  • direct connection to Raspberry Pi P5, assuming the header is mounted on the back side (as intended)
  • it uses SMD electrolyte capacitors, soldered on the back side (as well as the connection headers)

Download (81KB) - rev.6

RPi-DAC SingleStereo BOM

  • Bill Of Materials (parts and components) for RPi-DAC
  • including price estimate and Digikey [6] order numbers

Download BOM_RPi-DAC_rev6.pdf (60KB) - parts for PCB, optimized (with optional parts) - PCB rev.6 - new

RPi-DAC DualMono

  • Bill Of Materials (parts and components) for RPi-DAC DualMono
  • including price estimate and Digikey [6] order numbers
  • part location of main parts (R, C for signal processing, jumpers, not other R and blocking C

Download BOM_RPi-DAC_DualMono.pdf (65KB)

Download RPi-DAC_DualMono_soldering.pdf (827KB) (main parts)


  • Bill Of Materials (parts and components) for RPi-DAC-SPDIF
  • including price estimate and Digikey [6] order numbers
  • a User Manual for DualMono and RPi-DAC-SPDIF module

Download BOM_RPi-DAC-SPDIF.pdf (65KB)

Download Manual_RPi-SPDIF.pdf (492KB)

Solder and Assembling part locations - rev.6

  • Remarks how to solder, parts locations, BOM, schematics
  • based on PCB rev.6

Download RPi-DAC_rev_6.pdf (1MB) - new

How to operate rev.3 complete with RPi

  • for customers who got the entire setup (RPi + RPi-DAC + RPi-SPS)
  • how to connect AC transformer
  • commands to play audio files
  • requires to have modified Rasbian kernel for I2S on SD card

Download RPi-DAC-operate.pdf (85KB)

How to operate RPi-DAC DualMono with RPi

  • complete setup with SPS, transformer, RPi-DAC DualMono and RPi
  • Safety

Download RPi-DAC-operation_ger.pdf (85KB, GERMAN)

Separate PSU (universal)

  • version 1: using LT317 and for +3.3, +5V, +/-15V
  • version 2: using TI TPS7A45xx for all voltages, including negative -15V : requires transformer with separated coils

Download (20KB)

Download (25KB)

Stackable SPS PSU (for RPi-DAC)

  • using 4x TI LMZ14202H (2A)
  • directly stackable with RPi-DAC

Download (34KB)

Download BOM_RPi-DAC_SPS.pdf (54KB)

Download RPi-SPS_solder.pdf (396KB)

STMF4 Discovery USB Sound Card (Coocox Compiler)

  • for STMF4 Disovery, STMFD4 Disco, board
  • flash the board and use it as USB Sound Card
  • Use onboard headphone or feed the RPi-DAC
  • audio format: PCM 48KHz, 24bit, stereo
  • in order to use - it needs the STM32F4 C project (see below) or the BIN file to flash
  • please, see more details

Download Coocox project (31 MB)

Download BIN file (31 MB)

Xilinx ISE PCM1794A FPGA for XynergyXS

  • for XynergyXS board, in combination with the STM32F4, connected via FSMC
  • very simple Cortex-M4-to-FPGA bridge with FIFO to feed the PCM audio into DAC
  • contains clock generation for DAC BLK and SCLK
  • audio format: PCM 48KHz, 24bit, stereo
  • in order to use - it needs the STM32F4 C project (see below) and intended for the XynergyXS FPGA board [2]

Download (928KB)

Pico-C for XynergyXS STM32F4

  • a quite complex project for the STM Cortex-M4 on XynergyXS board
  • It contains a C-command-line interpreter with SD card support, FAT16 File System, Xilinx FPGA FSMC bridge (for DAC), USB OTG and USB Audio Class 1 driver and some other components such as ETH/LAN.
  • It supports to use the XynergyXS with T-DAC as USB Sound Card on a PC or to play WAV files from micro SD card.
  • It is a Coocox ARM Cortex-M4 project [5].
  • intended for the STM32F4 on XynergyXS FPGA board [2]

Download (1,136KB)

Schematics Collection

  • Find in PDF scatches, drafts, schematics, drawings etc., created and used during the project development.
  • It contains the DAC schematics as well as the PSUs.

Download T-DAC_Collection.pdf (451KB)


[1] see detailed circuit datasheets of original manufacturers

[2] Bayer DSP XynergyXS

[3] Xilinx ISE FPGA suite

[4] ExpressPCB

[5] Coocox ARM Compiler IDE

[6] Digikey electronic parts