This appendix describes the audio hardware specifications for the Indigo and Indigo2 workstations. It also contains some video specifications for IndigoVideo.
This section contains the specifications for the Indigo audio hardware.
Unless otherwise stated, all audio hardware parameters are measured under the following conditions:
analog input signal levels are +7 dB re: 1Vrms
digital input signal levels are 100% of full scale
48 kHz sample rate
input source impedances are 600 Ω
output destination impedances are 5 kΩ
measurement bandwidth is 10 to 30 kHz unweighted
All measurement results are typical. All connectors are single-ended 3.5-mm stereo phono plugs.
The following specifications describe the analog audio I/O.
Impedance: 5 kΩ nominal
Amplitude at full scale: 1 Vpp to 10 Vpp
Level control: two independent, digitally-controlled analog attenuators
Frequency response: 20 Hz–20 kHz ±0.25 dB
Total Harmonic Distortion + Noise (THD+N): < 0.003% @ 1 kHz, < 0.005% 20 Hz–20 kHz
Residual noise: -90 dB unweighted, -93 dB A-weighted (re: full scale)
Interchannel isolation: -76 dB @ 1 kHz, -68 dB @ 10 kHz,
-77 dB @ 20 kHz
Analog-to-Digital Converter resolution: 16-bit Delta-Sigma
Impedance: 2 kΩ
Amplitude at full scale: 0.25 Vpp to 2.5 Vpp
Power supply: +3 Vdc @ 1 mA
Type: omnidirectional electret condenser (powered by system)
Output level: 65 dB \xb1 4 dB @ 1 kHz (+0 dB = 1 V/0.1 pa)
Frequency response: 40 Hz–18 kHz \xb1 2 dB
Impedance: 600 Ω nominal
Amplitude at full scale: 6.0 Vpp
Frequency response: 20 Hz–20 kHz +0 dB, -0.8 dB
Total Harmonic Distortion + Noise (THD+N): <0.005% @ 1 kHz,
<0.02% 20 Hz–20 kHz
Residual noise: -85 dB unweighted, -92 dB A-weighted (re: full scale)
Interchannel isolation: -76 dB @ 1 kHz, -66 dB @ 10 kHz,
-61 dB @ 20 kHz
Digital output filter data resolution: 16-bit input, 18-bit output,
8× oversampling
Digital-to-Analog Converter resolution: 18 bits
Digital-to-Analog Converter sample rate: 8× oversampling
Headphone output impedance: 16 Ω
Headphone level: 200 mW into 32 Ω load
Headphone and speaker level control: two independent, digitally-controlled analog attenuators
Speaker: 2.6" diameter dynamic
Speaker sound pressure level: 88 dB/W
Speaker output level: 3 Watts max, 1.5 Watts nominal
The following specifications describe the digital audio serial I/O.
Impedance: 75 Ω, transformer-coupled
Level: 1 Vpp
Sample rates: 30 kHz to 50 kHz
Resolution: supports up to 24 bits per sample
Coding: AES-3, IEC-958
This section contains the specifications for the Indigo2 audio hardware.
Impedance: 20 kΩ nominal
Amplitude at full scale: 0.63Vpp to 8.4Vpp
Level control: analog gain control internal to CODECs
Frequency response: 20Hz–20 kHz \xb1 0.81 dB
Total Harmonic Distortion + Noise (THD+N): < 0.006% @ 1 kHz, < 0.007% 20 to 20 kHz
Residual noise: -86 dB unweighted, -88 dB A-weighted (re: Full Scale)
Interchannel isolation: -82 dB@1 kHz, -72 dB@10 kHz, -67 dB@20 kHz
Analog-to-Digital Converter resolution: 16-bit
Impedance: 1.5 kΩ
Amplitude at full scale: 0.063Vpp to 0.84Vpp
Power supply: +3Vdc @ 1mA
In 4-channel mode, the microphone input connector can be configured as a line-level input. When configured this way, it has the characteristics described in “Indigo2 Analog Stereo Line-level Inputs”
Impedance: 600 Ω nominal
Amplitude at full scale: 4.7 Vpp
Frequency response: 20 Hz–20 kHz \xb1 1.2 dB
Total Harmonic Distortion + Noise (THD+N): <0.02% 20 to 20 kHz
Residual noise: -81 dB unweighted, -85 dB A-weighted (re: full scale)
Interchannel isolation:-80 dB@1 kHz, -75 dB@10 kHz, -71 dB@20 kHz
Digital-to-Analog converter resolution: 16-bit
Headphone output impedance: 10 Ω
Headphone level: 57mW into 32 Ω load
Headphone and speaker level control: two independent, digitally-controlled analog attenuators
Speaker: 70mm by 40mm
Speaker sound pressure level: 80 dB @1W, 1meter
Speaker output level: 5W max, 2W nominal
In 4-channel mode, the headphone output connector is configured as a line-level output. When configured this way, it has the characteristics described in the “Indigo2 Analog Stereo Line-level Outputs”
The following specifications describe the digital audio serial I/O.
Impedance: 75 Ω, transformer-coupled
Level: 1 Vpp
Sample rates: 30 kHz to 50 kHz
Resolution: supports up to 24 bits per sample
Coding: AES-3, IEC-958