Nevion DAC-AES User Manual

DAC-AES
DAC-AES Audio Converter
User manual
Rev. 7
P.O. Box 1020, 3204 Sandefjord, Norway Tel: +47 33 48 99 99 Fax: +47 33 48 99 98
Nevion Europe
www.nevion.com
Nevion Europe P.O. Box 1020
3204 Sandefjord, Norway Support phone 1: +47 33 48 99 97 Support phone 2: +47 90 60 99 99
Nevion USA
1600 Emerson Avenue
Oxnard, CA 93033, USA
Toll free North America: (866) 515-0811
Outside North America: +1 (805) 247-8560
E-mail: support@nevion.com
See http://www.nevion.com/support/ for service hours for customer support globally.
Rev.
Repl.
Date
Sign
Change description
7 6 2011-06-23
AJM
Clarified supported bits in AES.
6 5 2010-08-09
AA
New template. Corrected drawings in Chapter 6.1 and 6.2. Updated Materials Declaration and Recycling information, and Declaration of Conformity.
5 4 2007-10-25
New front page and removed old logo.
4 3 2007-09-10
Added Materials Declaration and EFUP; updated EC Declaration of Conformity.
3 2 2004-02-10
C2 backplane descriptions.
2 1 2002-11-21
Typos
1 A 2002-09-19
Manual for first production batch
A - 2002-09-03
Preliminary version
Nevion Support
Revision history
Current revision of this document is the uppermost in the table below.
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Contents
1 General description ................................................................................................. 4
2 Block diagram .......................................................................................................... 5
3 Technical description ............................................................................................... 6
4 Configuration ........................................................................................................... 7
4.1 Analogue output levels .................................................................................................... 7
5 Specifications .......................................................................................................... 8
5.1 Measurement conditions.................................................................................................. 8
5.2 Digital Inputs .................................................................................................................... 8
5.3 Analogue outputs ............................................................................................................ 8
6 Connector module ................................................................................................. 10
6.1 ADC-AES-C1 ..................................................................................................................10
6.2 ADC-AES-C2 ..................................................................................................................10
6.3 Mounting the connector module ......................................................................................11
7 Connector pin drawings ......................................................................................... 12
7.1 Analogue signals ................................................................................................ ............12
7.2 C1 digital signals ............................................................................................................12
8 Module status ........................................................................................................ 13
8.1 LED’s – light emitting diodes ..........................................................................................13
General environmental requirements for Nevion equipment..................................... 14
Product Warranty ...................................................................................................... 15
Appendix A Materials declaration and recycling information..................................... 16
EC Declaration of Conformity ................................................................................... 17
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1 General description
The DAC-AES card is a reference quality audio D/A converter. It is one of the Flashlink series of modules. It will convert two AES3 (or AES-3id) stereo digital audio signals into four analogue audio channels with the highest possible quality. Dual analogue outputs for each converter are available on the backplane connector. The card may be used with nominal or double sampling rates.
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2 Block diagram
Figure 1
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3 Technical description
The DAC-AES card was designed as a reference audio converter with a highly audio optimized signal path. Careful design of the output circuitry was needed to maintain a high dynamic range whilst minimizing distortion. Jitter of the sampling clock is kept to a minimum by the use of a digital receiver with a large degree of hysteresis. The clock recovery scheme allows the sample clock to vary with a few PPM between an upper and lower limit.
The two D/A converters are totally independent and may be used with completely different input signals.
The AES receiver circuit signals the most important information about the received signal to the microcontroller, which sets up the appropriate parameters in the D/A converter. Non­audio and pre-emphasis are interpreted and used by the converter.
The output of the D/A converter feeds a differential second-order filter. This solution suppresses high frequency noise and the turn- on and off transients. The choice of op-amp is quite important in order to achieve a low output noise. The signal is then AC coupled to a non-inverting variable gain stage with gains ranging from 0 dB to 18 dB. The gain variation is performed by switching extra resistors in parallel to ground from the inverting input. The output is inverted with an inverting stage and the output stage is fed differentially.
The output circuit is a electronic differential amplifier with output level compensation. If either of the output phases is connected to 0V, the level of the other phase will increase to maintain the output differential signal level. Each converter has dual independent analogue outputs.
The card has a microcontroller that sets up the parameters of the D/A converters and controls the LEDs on the front of the card. It also monitors the 12V voltage level generated on the card and the 5V power voltage and reports to the Multicon Gyda controller when present.
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