640 AA
Common name: Western Electric 640 AA
Production Status: Discontinued / Vintage
The 640 AA is a medium diaphragm condenser measurement microphone capsule paired with the vacuum tube RA-1090 amplifier. The amplifier/powering unit uses a 382A vacuum tube. The 640 AA regulated power supply is needed to power the microphone and the amplifier. It can also be used as a recording microphone in auditoriums.
Electrical Characteristics
Frequency Response
50Hz - 15 kHz
Output Sensitivity
33.4 mV/Pa
Max SPL
Max SPL, THD:
Self Noise (CCIR)
dB
Self Noise (DIN/IEC)
dB-A
Output Impedance
50/250Ω
Recommended Load
Powering
Proprietary unit
Supply Current
(Heater) 150 mA
Alternative Powering
Switchable Options
Pad
Filter/EQ
Physical Characteristics
Connector
6-pin
Connector notes
Available Colours
Nickel.
Weight
Length
25.4 mm
Min diameter width
Max diameter
25.4 mm
Depth
Accessories
Included
Optional