Allen&Heath GL4000 SERVICE MANUAL - Manual (Page 11)

ALLEN & HEATH Section A - 6 L4DSM2
SPECIFICATIONS
0dBu = 0.775 Vrms Reference for high level equipment +4dBu =
1.23 V
0dBV = 1 Vrms
Reference for low level equipment -10dBV = 310 mV
0VU meter reading = +4dBu at XLR outputs
Input Gain
Mic/Line Input ............................................ +6dB to +60dB variable
Mic/Line + Pad ............................................ -14dB to +40dB variable
Line Input
............................................ -14dB to +40dB variable
Stereo Line Input ........................................... off to +10dB variable
2-track Return
............................................ off to +10dB variable
Maximum Output Level
Main Outputs ............................................ +27dBu into load of >600 ohm
Jack Outputs ............................................ +21dBu into load of >2K ohm
Internal headroom ......................................... +21dB
Frequency Response
Measured 20Hz to 20kHz ref 1kHz
Mic to mix (+40dB) ....................................... +0/-0.5dB
Line to mix (0dB) ........................................... +0/-0.5dB
Distortion
THD + noise measured @ 1kHz +20dBu
Mic to mix (+40dB) ....................................... 0.006%
Line to mix (0dB) ........................................... 0.006%
Crosstalk
Referred to driven channel @ 1kHz
Channel to channel ....................................... > 100dB
Mute shutoff
............................................ > 85dB
Fader shutoff ............................................ > 90dB
Noise Performance
Measured rms 22Hz to 22kHz bandwidth
Mic EIN
............................................ -128dB 150 ohm source
Line pre-amp (0dB) ........................................ < -91dBu
Residual output noise .................................... < -98dBu (-102dB S/N)
Mix noise, nothing routed .............................. < -87dBu (-91dB S/N)
Mix noise, 24 channels routed ...................... < -81dBu (-85dB S/N)
Metering
Input meters ............................................ 4 segment LED (signal, 0, +6, peak)
Mix meters ............................................ 4 segment LED (signal, 0, +6, peak)
Output meters ............................................ 12 segment LED
LED meter response ..................................... peak reading
Peak indicators ............................................ on 5dB before clipping
Signal indicators ........................................... on -20dBu
VU meterpod
............................................ Illuminated VU moving coil meters