Revision C • 1/04
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1 General Information
digital
Specifications
The specifications for the BMX
digital are sig-
nificantly more complete, and the related test con-
ditions are more defined, than those usually shown
for consoles in this class. Be sure to follow the test
conditions and measure in the units as stated.
The specifications are for a fully loaded BMX-
digital 38-input mainframe.
Test Conditions:
Specifications are for the basic signal paths, per
channel, with >1 k ohm loads connected to the
analog main outputs.
0 dBu corresponds to an amplitude of 0.775
volts RMS regardless of the circuit impedance. This
is equivalent to 0 dBm measured into a 600 ohm
circuit for convenient level measurement with
meters calibrated for 600 ohm circuits. Noise speci-
fications are based upon a 22 kHz measurement
bandwidth. The use of a meter with 30 kHz band-
width will result in a noise measurement increase
of approximately 1.7 dB.
Total Harmonic Distortion (THD+N) is mea-
sured at a +18 dBu output level using a swept
signal with a 22 kHz low pass filter.
FSD = Full Scale Digital, +24 dBu
Microphone Preamplifiers
Source Impedance:
150 ohms
Input Impedance:
5 k ohms minimum, balanced
Input Level Range:
Adjustable, -65 to -30 dBu
Input Headroom:
>20 dB above nominal input
Output Level:
+4 dBu, nominal
Analog Line Inputs
Input Impedance:
>40 k ohms, balanced
Input Level Range:
Selectable, -10 dBv, +4 dBu,
+6 dBu, +8 dBu
Input Headroom:
20 dB above nominal input
Analog Main Outputs
Output Source Impedance:
<3 ohms balanced
Output Load Impedance:
1 k ohms minimum
Nominal Output Levels:
Program, Utility, Send, Telco/
Codec Mix-Minus, Telco Record Mix Feed: +4
dBu, adjustable b3 dBu and +9 dBu
Maximum Output Levels:
Program, Utility, Send,
Telco/Codec Mix-Minus, Telco Record Mix Feed:
+24 dBu; +28 dBu with nominal output level
adjusted to +8 dBu
Digital Inputs and Outputs
Reference Level:
+4 dBu (-20 dB FSD)
Digital I/O:
Thru digital input and digital Program,
Utility, Send, Telco/Codec Mix-Minus outputs
Signal Format:
AES-3, S/PDIF (input only)
AES-3 Input Compliance:
24-bit sample rate conver-
sion available, individually switch selectable
AES-3 Output Compliance:
24-bit
Digital Reference:
Crystal (internal) or AES-3 (ex-
ternal) at 48 kHz ±100 ppm
Internal Sample Rate:
48 kHz
Output Sample Rates:
Program Main outputs are
48 kHz; Program Aux, Utility, Mix-Minus and
Telco Record Mix outputs, individually DIP
switch set for 48 kHz or 44.1 kHz
Processing Resolution:
24-bit fixed with extended
precision accumulators
Conversions:
A/D 24-bit, Delta-Sigma, 128x
oversampling on all digital inputs; D/A 24-bit,
Delta-Sigma, 128x oversampling
Latency:
<1.6 ms, mic in to monitor out
Monitor Outputs
Output Source Impedance:
<3 ohms, balanced
Output Load Impedance:
1 k ohms minimum
Output Level:
+4 dBu nominal, +24 dBu maximum
Frequency Response
Microphone or Line Input to Program, Utility, or Send
Output:
+0 dB/-0.5 dB, 20 Hz to 20 kHz
