Meyer Sound LD-1A User Manual

10
Specifications
Architecture
Main (Channels 1, 2)
Master Gain Control -12 to +6 dB
Mid-Hi, DS-2, Sub Gain Controls -12 to +6 dB
Low-cut Filter for Mid-Hi 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 k 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)
Auxiliary 1 female XLR/channel
Wiring Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal
Drive Capability
Maximum Voltage
1
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 Drives > 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 µsec 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
Physical
Dimensions Height: 3.45 inches (2 rack spaces); Width: 16.75 inches; Depth: 6.96 inches
Weight 13.5 lb (6.1 kg); shipping: 15 lb (6.8 kg)
Enclosure/Finish Black 16-gauge steel chassis;
1
/8 inch aluminum rack ears
Notes
1. 0 dBV = 1 Vrms; 0 dBu = 0.775 Vrms; 0 dBm = 1 mWrms
2. Ratio of maximum sinewave to A-weighted noise floor.
3. Level set to unity gain (0 dB).
4. 0 dBV, 1 kHz sinewave input. Gain at +12 dB main
channel, +6 dB auxiliary channel.

Meyer Sound LD-1A Specifications

Audio Inputs

input impedance	10 k differential
common mode rejection ratio	> 80 dB
rf filter common mode frequency	425 kHz low-pass

Audio Outputs

output impedance	50 Ohm balanced
maximum voltage with 600 Ohm load	±22.5 Vpk
maximum current	±70 mApk

AC Power

operating voltage	90 - 125 VAC / 180 - 250 VAC
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
dynamic range	> 120 dB
noise floor	> -95 dBV A-weighted

Physical

height	3.45 inches
width	16.75 inches
weight	13.5 lb