Wednesday, October 22, 2014

D.I.Y. Guide

Thank you for choosing exaU2I for your very special high-end audio project. We hope you will enjoy it as much as we enjoyed designing, building and using it in our own D.I.Y audio systems.

Please be careful – exaU2I can be destroyed by static, shortcuts, …

Quick Start

The fist thing to do probably is to put exaU2I to a very quick test. You can install an ASIO capable audio player, the ASIO exaU2I driver, connect the USB cable and play something. You will see the power light on. The FIFO light will come on when you start playback. One of the sync LEDs will indicate the sampling frequency set by your player.

You can find step by step instructions how to setup an ASIO player and driver in the following sections of this document.

When you are done with the quick test, you will know that your music source is working and exaU2I is behaving as expected. At this point you can look at the schematics and connect exaU2I to your DAC or DACs.

The only special note to make is that you have to use the DAC power supply for the exaU2I outputs. More specifically, you have to use the power supply that powers the digital inputs of your DAC(s). The exaU2I output circuits are galvanically isolated from the rest of the board. They operate as a part of your DAC.

Setup and Configuration


1. ASIO Driver Installation

The first step required in the setup process is to install the ASIO driver for exaU2I:
  1. Don’t connect the exaU2I device to the PC until the driver is installed. Following this rule makes troubleshooting easier. Don’t worry if you’ve connected the device already. Just disconnect it.
  2. 2. Download the latest driver from this website.  Make sure your antivirus software is running before you start the download. Do not use divers downloaded from other websites. 
  3. Double-click on Install.exe to start the installation. Follow the instructions. In most cases you just need to accept the defaults on the following screens.
  4. Connect the exaU2I device. You should see the PWR LED on. You should see a pop-up message on the computer screen indicating that exaU2I device is successfully installed.

2. Configuring Audio Player with ASIO Output

You can use any ASIO-enabled software to stream PCM audio to exaU2I. In our experience

Foobar, J. River Media Center and AlbumPlayer provided the best performance and sound quality. Other PC audio software that can be used include Winamp and MediaMonkey. There is an ASIO output plug-in for Windows Media Player; unfortunately we were unable to make it work. You can find information on the Internet about installing and configuring these applications for use with ASIO drivers.


See Appendix A at the end of this document for step by step instructions for installing Foobar2000 and configuring the Foobr2000 ASIO output plug-in.

3. Connecting exaU2I to Your DAC Kit(s)

exaU2I will work with most DIY DAC boards with I2S input. For our own projects we use a DAC kit based on the ESS Technology ES9018 Sabre32 Reference chip. At the present time ES9018 is the only chip that we were able to drive at 352.8 kHz and 384 kHz. Let us know about experience with other DACs.

Note: The length of the connection cables should be less then 100mm.

Connection to ES9018 DAC Kit in Stereo Quad Differential Mode

exaU2S Terminal  Name

ES9018 DAC Kit Terminal  Name

GND

GND

DVCC

DVCC

DCK

DCK

LR

D1

D.1.2

D2

D.3.4

To D2 of next board for channel 3 and 4

D.5.6

To D2 of next board for channel 5 and 6

D.7.8

To D2 of next board for channel 7 and 8

SCK

Not used – leave disconnected



Connection Example - Four Channel ES9018 in Quad Mode




Connection Example - Two Channel ES9018 in Quad Mode




Connection Example - Eight Channel ES9018



Connection Examples for Popular DACs

exaU2S Terminal  Name

ES9018

 

AD1955

PSM1792

CS42528

GND

GND

DGND

DGND

DGND

DVCC

DVCC

DVDD

VDD

VLS

DCK

DATA_CLK

BCLK

BCK

CX_SCLK

LR

DATA1

LRCLK

LRCK

CX_LRCK

D.1.2

DATA2

SDATA

DATA

CX_SDIN1

D.2.3

DATA3

SDATA to other chip(s)

DATA to other chip(s)

CX_SDIN2

D.5.6

DATA4

SDATA to other chip(s)

DATA to other chip(s)

CX_SDIN3

D.7.8

DATA5

SDATA to other chip(s)

DATA to other chip(s)

CX_SDIN4

SCK

-

MCLK

SCK

OMCK



Terminal Functions

Terminal  name

Description

GND

Connect to the digital ground of the DAC.

DVCC

Power supply of the isolated digital output buffers.

Must be connected to the DACs digital power supply positive terminal. Accepts from 3.3V to 5V. Consumption is less then 20mA.

DCK

Data bit clock output for the I2S interface. 

LR

Left-Right I2S interface synchronization output. It has the same frequency as the sampling frequency. Low level indicates the left channel data transfer. High level indicates right channel data. In multi-channel mode low level means odd channels transfer and high level - even channels transfer. 

D.1.2

Serial data output in I2S 32bits format for channels 1 and 2.

D.3.4

Serial data output in I2S 32bits format for channels 3 and 4.

D.5.6

Serial data output in I2S 32bits format for channels 5 and 6.

D.7.8

Serial data output in I2S 32bits format for channels 7 and 8.

SCK

Output source of master clock for the DAC if required.

11.289MHz for sampling freq. 44.1, 88.2 and 176.4kHz.*

24.576MHz for sampling freq. 48, 96 and 192kHz

*Sampling frequencies 352.8 kHz and 384 kHz are possible only on ES9018 and ES9012 DACs when SCK signal is not used.

 
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exaDevices delivers innovative and alternative solutions for highest-quality music playback to leading-edge DIY enthusiasts.  Our products are built and supported for personal hobby use only. Commercial use, duplication or distribution in any form is not permitted.

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