Introduction
This application note details how to wire AudioScience audio adapter analog and digital connectors. Both balanced and unbalanced options are discussed.
Analog Connectors
There are 6 different types of connectors used for analog audio I/O:
DB9 | ASI41xx series, ASI5111/5211 |
DB25 | ASI450x series (OEM only) |
DB26 (High Density) | ASI4215, ASI58xx series |
50pin Centronics | ASI43xx series, CBL1004 |
High Density 50pin | ASI500x, ASI504x, ASI5x20, ASI554x, ASI564x, ASI6xxx, ASI65xx, and ASI66xx series, CBL1044, CBL1004 |
VHDCI | ASI57xx, ASI67xx, BOB1038 |
Analog signals are balanced and consist of a "+" and "-". The actual signal is the difference between the + and -.
Balanced Analog Operation
For a balanced output, the following connections are made to an XLR connector (using Left input/output #0 as an example)
Unbalanced Analog Operation
For unbalanced operation, connect the "-" side of the signal to ground. The "+" side becomes the signal. This applies to both an input and an output. You will not damage the output driver of the adapter by connecting the "-" signal to ground; the driver is designed to operate in this fashion (however, if you connect both + and - to ground then you may cause damage). 
Combination connectors
ASI5810, ASI5811 and ASI5812 cards use a single DB-26HD connector for analog, AES/EBU and GPIO connections.
Digital (AES/EBU - S/PDIF) connectors
There are 5 types of digital connectors:
DB9 | ASI41xx, ASI45xx series, ASI5111/5211 |
DB15 (High density) | ASI4215 |
| DB26 (High density) | ASI58xx series |
50pin Centronics | CBL1101, CBL1144 |
High Density 26pin | ASI5002, ASI504x, ASI564x, ASI6xxx, ASI65xx, ASI66xxseries, CBL1101 |
VHDCI | ASI57xx, ASI67xx, BOB1038 |
AES/EBU Balanced Operation
For a AES/EBU input or output, the following connections are made to an XLR connector (using AES input/output #0 as an example):
S/PDIF Unbalanced Operation
For S/PDIF operation, connect the "-" side of the signal to ground. The "+" side becomes the signal. This applies to both an input and an output. You will not damage the output driver of the adapter by connecting the "-" signal to ground; the driver is designed to operate in this fashion (however, if you connect both + and - to ground then you may cause damage).
RJ-45 connector for BOB1025
RJ-45 Pin Number | Color Pair | Channel |
1 | White/Orange | L+ / AES+ |
2 | Orange/White | L- / AES- |
3 | White/Green | R+ |
4 | Blue/White | GND |
5 | White/Blue | nc |
6 | Green/White | R- |
7 | White/Brown | 15V- |
8 | Brown/White | 15V+ |
Combining Left and Right channels with resistors to create a single, mono channel.
Join left and right using 10K resistors:
L + -----/\/\/\/--------+--------o M +
10K |
R + -----/\/\/\/--------+
10K
L - -----/\/\/\/--------+--------o M -
10K |
R - -----/\/\/\/--------+
10K