TransportPi Digi/II/III, Audiophile master mode Digi re-clock streamer transport

Introduction

TransportPi Digi is an audiophile grade high-performance low-cost master mode all-in-one Raspberry Pi interface transport. It successfully achieves an ultra-low jitter low noise signal quality by using IanCanada's well reputed 1-bit three stages discrete re-clock technology for the S/PDIF signals and two-stages multi-bits re-clockers for the I2S over HDMI signals. TransportPi Digi also has dual XOs sockets for local audio clocks to make it possible to be upgraded to even higher sound quality level by installing OCXOs or other kinds of ultra-low phase noise clocks.
As an all-in-one digi transport, it provides almost all kinds of high quality re-clocked output: RCA, OPT, HDMI and GPIO. Because of the most advanced low-jitter and low-low noise technologies it employs, TransportPiDigi could be the best sound quality compact size RPi streamer transport when working with UcPi, PurePi or other high quality power supplies.
TransportPi Digi is functionally equivalent to a I2S FIFO re-clocker plus a TransportPi.

Launched in late 2026, the New TransportPi Digi III Streamer transport represents an enhanced performance upgrade over its predecessor.

Features and Specifications

• Four high-quality low-jitter digital audio outputs: re-clocked S/PDIF output in RCA (Isolated) and OPT, re-clocked I2S output over HDMI, re-clocked I2S output over GPIO.
• Low noise 1-bit discrete re-clocker for S/PDIF signals (three stages in total).
• Two-stages multi-bits re-clocker for I2S over HDMI signals.
• 45.1584/49.1520 MHz dual low phase noise local clocks were pre-installed in the upgradeable/swappable XO sockets which are compatible with FifoPi. 22.5792 /24.5760 MHz clocks can also be used.
• Has high quality local MCLK output in U.FL coaxial cable connector.
• Can also work as an I2S FIFO re-clocker.
  
• Can also share Raspberry Pi ‘s power supply.
• Works with SinePi to take external high quality sine clocks.
• Great for compact size audiophile integrated Raspberry Pi streamer transport solution.
• Up to PCM 192KHz.
• Four layers PCB design with two inner PCB layers as dedicated shield plates to lower the noise more.
  
• Achieve re-clocker function without need a FifoPi to work with.
• Use standard WM8805 Linux driver.
• Supplied with higher grade FemtoMck 45.1584/49.1520 MHz clocks, as the same as FifoPiQ7
• Direct 3.3V input optimized for high quality low noise battery/ultracapacitor power supply
• Mute control for I2S over HDMI
• New S/PDIF digital transformer
• Enhanced coaxial signal quality, capable of working in high EMI noise environment
• Low cost but no compromise on performance
• bit-perfect and lossless
• DIY friendly plug-and-play
• Top level manufacturer quality

TransportPi Digi III — New Features and Improvements

1. New high-current, ultra-low-noise LDO significantly improve the quality of the 3.3V power supply. On-board LDO can also be bypassed.
2. Enhanced local power-supply filtering featuring higher capacity ultra-low-ESR polymer capacitors, combined with high-bandwidth filtering, minimizes the power-supply noise floor and provides cleaner, more stable power to help reduce jitter in critical digital output circuits.
3. Allows a compatible DAC to be installed directly on top of the TransportPi Digi III, enabling the combined system to function as both a high-quality digital audio streamer transport and a high-performance re-clocking DAC within a single configuration.
4. Optimized PCB design with tighter impedance control improves signal integrity and further reduces the overall noise level.
5. Precision-engineered construction with meticulous attention to detail ensures high standards of hardware quality, consistency, and long-term reliability.

Note: 

1. Jumpers on J2 of the TransportPi Digi must be removed if supply independent 3.3V to J3 without installing an IsolatorPi.
2. Please use supplied 11mm M2.5 standoffs when installing directly to a RPi. But have to use 13mm M2.5 (#12A) standoffs when installing on top of IsolatorPi, ShieldPi or other IanCanada PCBs.
3. #20B TransportPi Digi (ATU) is upgraded with AT-Ultra clocks, which have nature and analog sound signatures. But TransportPiDigi II/III with equipped FemtoMck clocks are still at a bit higher levels.

TransportPi Digi III User's manual

DXF file of TransportPi Digi III

TransportPi Digi II User's manual

TransportPi Digi User's manual

TransportPi Comparison

Other Documents

Possible upgrade

SC-Pure clocks(#80A and #80B)
UcConditionerPro 3.3V
Spike feet
Acrylic cover

Typical Applications

1. Basic network re-clock streamer transport
   TransportPi Digi (II/III)
   RaspberryPi
   
2. High-performance low-cost RaspberryPi Digi re-clock Streamer Transport and DAC
   (1). Raspberry Pi
   (2). ShieldPiPro with MonitorPi Pro
   (3). TransportPi Digi (II/III)
   (4). ES9038Q2M DM III DAC
   (5). Transformer I/V
3. Low cost  good sound quality Digi re-clock streamer transport with ultracapacitor power supply
   (1). Raspberry Pi
   (2). TransportPi Digi (II/III)
   (3). MonitorPi Pro
   (4).UcPi 2025
   
4. Audiophile grade Digi re-clock Streamer Transport using PurePi ultracapacitor/battery power supply
   (1). Raspberry Pi
   (2). TransportPi Digi (II/III)
   (3). MonitorPi Pro
   (4).PurePi
   
5. High-end compact size RaspberryPi Digi re-clock Streamer Transport using IsolatorPi and PurePi ultracapacitor/battery power supply (Recommended)
   (1). Raspberry Pi
   (2). TransportPi Digi (II/III)
   (3). IsolatorPi III
   (4). MonitorPi Pro
   (5).PurePi
   

Helpful link from user