DSP KIT 3x2 HD, USB DAC+DSP+ADC Motherboard with ADAU1701 digital audio processor

Hardware features
The DSP KIT 3x2 HD platform is based on the ADAU1701 audio processor. The motherboard has two highly stable oscillators at 11.2896 MHz and 12.288 MHz for each frequency grid (44.1/48). The generators are connected to the DSP by a logical control circuit. Each generator has its own linear power supply. All voltages for the ADAU1701 audio processor are stabilized by linear converters.
All logical and audio ports of the ADAU1701 are connected to the board via connectors.
One input and one output I2S audio port are connected to the HDMI connectors via differential line drivers. These are the so-called I2S inputs and outputs via HDMI.
Any DAC and more than one can be connected to any I2S output port (for multi-channel audio, subwoofer). The I2S via HDMI input port only works in Master mode due to the features of the ADAU1701. Take this into account in your projects.
The board has a 256 kbit serial non-volatile memory chip.
The main feature of the platform is full compatibility with USB-audio Reflex transport.
After connecting the Reflex USB audio transport to the motherboard, the platform becomes a full-fledged external USB audio DSP. With the ability to connect up to 9 external controls and displays. Buttons, encoders, variable resistors, and up to 16 LEDs with pixel indication type WS2812.
You can connect a SmartTV with built-in CEC technology to the HDMI service connector marked CEC. In this case, you can adjust the volume from the TV remote control and turn the TV on/off from the device.
Everything you were missing in the audio projects on the RDC2-0027 with the ADAU1701 chipboard is now on this motherboard. It includes all the additional schemes that are used in high-quality projects on ADAU1701 and even more.

Brief hardware specifications

• Processor: ADAU1701
• Digital inputs: I2S via HDMI/USB audio with Reflex connection
• Digital outputs: I2S via HDMI
• Analog inputs: stereo, 2 channels
• Analog outputs: 4 channels
• HDMI CEC input - volume control on/off from the remote control.
• Supply voltage: 12V - 1A
• Board size: 171 x 147 mm

Software features
The ADAU1701 DSP platform is compatible with the SigmaStudio software environment. You can create any project, listen to it, configure it, and upload it to the non-volatile memory on the motherboard. To do this, you will need the SigmaLink USBi programmer.
If you have installed the Reflex transport, you can use the ChipStudio environment to load the project directly into the Reflex memory. This option will open up all the features of SigmaStudio and ChipStudio software for you. With the ability to adjust, switch, display and connect all algorithms created by Analog Device for the ADAU1701 processor.
Using ChipStudio, you can also rename Reflex and it will be identified by the OS under your name.

The block diagram



All in one!

1. DSP ADAU1701 with auxiliary elements, including EEPROM M24C64 (DD1) for storing user projects, a 3.3 -> 1.8 V voltage converter (VT4) is needed to power the ADC core, PLL generator elements (C27, C28 and R30).
2. Two highly stable oscillators at 11.2896 MHz and 12.288 MHz for each frequency grid (44.1/48). The generators are connected to the VT2 DSP control logic circuit. Each generator has its own buffer for connection to external circuit elements (DD3, DD4) and its own linear power supply (DA2, DA3). The circuit is from the KiCad project, so you see three oscillators for each frequency. This is done only in order to get three different seats on the printed circuit board. Don't pay any attention.
3. I2S audio ports, inputs and outputs. Each digital signal is buffered by the 74LVC1G125 driver. DA5-DA9 outputs, DA16-DA18 inputs.
4. Second-order RF output on an audio op AMP with ultra-low noise and distortion OPA1656. Four analog outputs. Transmission ratio=1
5. Linear power supplies for DA5 for op amp=9V and DA1 for DSP ADAU1701=3.3V
6. DC-DC 5V converter for powering the power management module (8), REFLEX and I2S via HDMI circuits
7. The place to install Reflex
8. The board's power management unit.
9. Connectors for connecting external controls. Buttons, encoders, variable resistors, and up to 16 LEDs with pixel indication type WS2812.
10. The I2S via HDMI digital audio output is mounted on an AM26LS31 differential linear transmitter. The circuit is fully compatible with the HDMI/I2S audio adapter. You can connect it with a standard HDMI cable. By connecting an RDC2-0059 amplifier to an adapter, for example, you will receive two more audio channels of 30 watts each.
11. I2S digital audio input via HDMI. The circuit is based on the SN75176 drivers
12. Analog inputs
13. HDMI CEC input - volume control on/off from remote control
14. Configuration connector for Reflex

An example of a "Pre-amp - timbre block" project
You can download it from the Technical Documentation section.
ChipStudioProject
SigmaStudioProject

An example of connecting Reflex and the DSP KIT SBTW control panel.

https://static.chipdip.ru/lib/072/DOC058072552.jpg

After uploading the project to Reflex, we will get a timbre block with analog and digital inputs, analog outputs, and adjustments: input selection, volume, bass, treble, Mute, and SuperBass timbres.

The ChipStudio Project

Technical support is provided on our forum.