Meyer Sound LD-1A

Physical
Dimensions: 16.75" w x 3.45" h (2 rack spaces) x 6.96" d
Weight: 6.12 kg
Enclosure/Finish: Black 16-gauge steel chassis; 1/8" rack ears

Architecture
MAIN (Channels 1,2)
Controls: -12 to +6 dB
Mid-Hi, Mid-Bass/Aux, Sub Gain Controls: -12 to +6 dB
Low-cut Filter for Mid-High output: 160 Hz high-pass, -12 dB/octave, Q = 0.8
Array EQ Filter for Mid-Hi Output: 6 dB cut at 220 Hz, 0.6 octave bandwidth
Mute: Mute switches for Master, Mid-Hi, DS-2, and Sub outputs
Polarity: Toggles for Sub and DS-2 outputs

AUXILIARY (Channels 3-8)
Gain Control: -12 to +6 dB
Low-cut filter: 160 Hz high-pass, -12 dB/octave, Q = 0.8
Array EQ Filter: 6 dB cut at 220 Hz, 0.6 octave bandwidth
Mute: Mutes the channel output

Audio Inputs
Connector: 1 female XLR per channel
Type: Differential balanced input circuit
Impedance: 10 kΩ differential (between pins 2 and 3)
Wiring: Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal
RF Filter: Common Mode: 425 kHz low-pass; Differential Mode: 142 kHz low-pass
Common Mode Rejection Ratio: > 80 dB (typically 90 dB); measured in the range 50 Hz - 1 kHz
Signal Presence: LED (Variable intensity; monitored at the input for each channel)
Threshold: -26 dBV (50 mVrms) pink noise or sinewave
Full Intensity: -10 dBV (300 mVrms) pink noise or sinewave

Audio Outputs
Type: Balanced, cross-coupled simulated transformer topology
Impedance: 50 ohm balanced (between pins 2 and 3)
RF Filter: Pins 2 and 3 shunted to chassis via 500 pF capacitance

CONNECTORS
Main: 4 female XLR/channel (Mid-Hi, DS-2, Sub, Loop)
Wiring: Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal

DRIVE CAPABILITY
Maximum Voltage: 600 ohm Load: ±22.5 Vpk (+24 dBV, +26.2 dBu sinewave) No Load: ±25.0 Vpk (+25 dBV, +27.2 dBu sinewave)
Maximum Current: ±70 mApk (10 Vrms into 200 ohm)
Cables and Load: > 100,000 pF (> 1000 ft cable) without instability or distortion

AC Power
Connector: IEC 320 (line, neutral/line, earth)
Operating Voltage: 90 - 125 VAC / 180 - 250 VAC (selectable with rear panel switch); 50/60 Hz
Maximum Power: 25 Watts; Fuse: 5 x 20 mm, T 250 mA, 250 V, time-lag

Audio Performance
Frequency Response: < ±0.2 dB 20 Hz - 20 kHz
Bandwidth: DC to 60 kHz (-3dB)
Phase Response: < ±3° from pure 3 micro-sec delay (DC - 20 kHz)
Dynamic Range (2): > 120 dB
Noise Floor (3): > -95 dBV A-weighted; > -90 dBV un-weighted
THD + N (4): < 0.005% (typically 0.002%)
Gain Accuracy: < ±0.15 dB at +6 dB gain; < ±0.25 dB at 0 dB gain
Mute Attenuation: > 100 dB

GAIN RANGE
Main Channels: -24 to +12 dB
Auxiliary Channels: -12 to +6 dB