Handbook

Redbox User Handbook No 1

DIGITAL AUDIO CONVERTERS

DIGITAL AUDIO CONVERTERS - RB-ADDA2

Sync Button

and LEDs

Frequency Set

Button and LEDs

Bits Button

and LEDs

A/D Source Select

Button and LEDs

CS Data Button

and LEDs

D/A Source Select

Button and LEDs

Reset

Button

2 RB-ADDA2 Combined A/D and D/A Converter 24bit 192kHz

Introduction

Fig 2-1: RB-ADDA2 Front Panel

The RB-ADDA2 A/D and D/A converter is a 1U rack-mount which produces

an AES/EBU, S/PDIF or TOSlink optical level digital audio output from a

balanced XLR or unbalanced phono stereo audio input. It also produces

a stereo balanced XLR or unbalanced phono output from an incoming

AES/EBU, S/PDIF or TOSlink optical digital input signal.

The RB-ADDA2 is a high performance, enhanced version of the RB-ADDA providing the

following additional features:

• Itsupportshighersamplefrequencyratesuptoandincluding176.4kHzand192kHz.

• IthasadditionalindependentAES/EBUandWordClocksynchronisinginputs,so

that the A/D and D/A sections can operate independently, with the digital outputs

synchronised to an external master reference clock.

• IthasTOSlinkopticaldigitalaudioinputandoutput.

• Ithasfrontpanelpush-buttonswitchesforallthemainsettings.Thebuttonsare

arranged in sets, where pressing the button advances the current selection and

LED indicator.

• AserialRS232portisincludedsothattheRB-ADDA2settingscanbecontrolled

remotely. The front panel LED indicators alter automatically when using RS232

commands.

The A/D SOURCE push-button is used to select from either the balanced or unbalanced

stereo analogue inputs and this push-button also denes the input level for full scale digits

at one of +12dBFS, +18dBFS or +24dBFS. These values can then be ne-tuned by using

rear-panel pre-set potentiometers which give another ±3dB of gain adjustment, allowing

a signal range from +9dBu to +27dBu. The RCA phono inputs have a further 10dB nominal

gain incorporated to give a total signal range of -1dBu to +17dBu for full-scale digits.

For the digital output, there are three push-button switches to select the sample frequency,

bit depth and status bit modes. The FREQUENCY button allows selection of the master

sample frequency from one of 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz.