Sony ECM-77S Service Manual

Photo: ECM-775S
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E Model
J Model
US Model
ECM-77S: Silver type
ECM-77B: Black type
ELECTRET CONDENSER
MICROPHONE
SPECIFICATIONS
Electret condenser microphone
Battery: IEC designation R6 or LR6
(size AA)
External power:
Phantom powering system
For J and E models, use optional Sony
AC-148F external power supply.
Type
Power supply
Power requirements
Normal operating voltage:
1.5 Vde at battery operation
48 Vdc at external power operation
Minimum operating voltage:
1.1 Vde at battery operation
Current drain:
Less than 0.2 mA (with battery)
Less than 2mA (with external power
supply)
Battery life:
Approx. 5,000 hours with Sony
SUM-3 (NS) New Super Battery
(manganese battery)
Approx. 6,000 hours with Sony
Eveready AM3 (LR6) alkaline battery
Frequency range 40—20,000 Hz
Directivity
Output impedance
150 ohms +20% (1 kHz), balanced
Sensitivity (deviation +2 dB)
Open circuit voltage:
—52.0dB (2.51mV, 0dB = 1V/1 Pa,
1 kHz)
Effective output level:
~—49.8dBm
(0 dBm = 1 mW/1 Pa, 1 kHz)
Recommended load impedance is more
than 3 kohms.
Omni-directional
Continued on next page.
SONY.
SERVICE MANUAL