BRUEL & KJAER MICROPHONE AMPLIFIER 2603, 1960's

The Bruel & Kjaer Microphone Amplifier is part of a system known as the 'Electroacoustic Telephone Measuring system'. The instruction manual reads: - ‘’The microphone Amplifier Type 2603 is an accurate, multi-purpose instrument for use in the sound and vibration measuring field as well as in ultrasonic measurements. The instrument consists basically of an input amplifier section, the proposed IEC standard weighting networks 'A', 'B' and 'C' for Precision Sound Level Meters (Helsinki 196), and an output amplifier section.
Provision is made for the insertion of external filters between the amplifier sections. an output terminal makes it possible to connect the amplifiers to an a.c. recording instrument e.g. the B & K level Recorder Type 2305’’.
See Item A1882B. See also microphones Item A1864.

Donated by John Barnes.

A1884