Manual

Chapter 4 - RB-ADDA Combined A/D and D/A Converter
Redbox User Handbook 4-7
4.4.3.6. Test/Calibration Mode
For optimum performance of the RB-ADDA, the unit should be calibrated when it has
been powered up for approximately 10-15 minutes. The circuitry and chipsets
contained in the unit will warm up during this time and the performance will
deteriorate unless calibrated (the noise floor and dynamic range will be 1-2dB down
on their best). The calibration cycle calibrates the gain and the zero reference of the
A/D converter.
To calibrate the RB-ADDA, set the rotary FREQUENCIES AND SYNC MODES switch to
position “F”. The power LED on the front panel will flash quickly for 2 – 3 seconds and
will illuminate fully when the unit is calibrated. Once calibration is complete, reset the
rotary switch to the position that you require.
4.5. Technical Specifications
4.5.1. A/D Connections
Analogue Inputs: 2 x XLR 3 pin (balanced) (L & R)
2 x RCA phono (unbalanced) (L & R)
Digital Outputs: 1 x AES/EBU XLR 3 pin plug
1 x S/PDIF RCA phono socket
4.5.2. A/D Audio Specification
Maximum Input Level: +27dBu (balanced inputs)
Maximum Input Level: +17dBu (unbalanced inputs)
Input Impedance: >10kΩ bridging (balanced inputs)
Input Impedance: >20kΩ (unbalanced inputs)
Input Levels: Switchable +24dBu/+18dBu/+12dBu for FSD
Gain Range: Adjustable 3dB loss to 3dB gain (L and R adjust)
Signal to Noise: Better than –109dbFS (RMS A-weighted at 24bit)
Dynamic Range: >110dB
Distortion and Noise: >96dB THD + N at 1kHz
4.5.3. D/A Connections
Digital Inputs: 1 x AES/EBU XLR 3 pin female
1 x S/PDIF RCA phono
Analogue Outputs: 2 x XLR 3 pin male (balanced) (L & R)
2 x RCA phono (unbalanced) (L & R)
4.5.4. D/A Audio Specification
Max Output Level: +24dBu (balanced outputs)
Max Output Level: +14dBu (unbalanced outputs)
Output Impedance: <50Ω (balanced outputs)
Output Impedance: <75Ω (unbalanced outputs)
Dynamic Range: >100dB
Gain Range: Selectable 12dBu, 18dBu or 24dBu output level, ref FSD