Sony 37A (c. 1955)

Almost nothing is documented about a Sony "37A" under that exact name. The model the period record points to is the C-37A, a condenser microphone. A 1994 collector profile in EQ Magazine (March 1994, p.28) identified it as Sony's first condenser microphone, dating to roughly 1955. It described the C-37A as a rugged design made primarily for broadcast use.

Type: condenser microphone, switchable cardioid/omnidirectional
Frequency response: ±2 dB, 20–18,000 c.p.s. (cycles per second)
Output impedance: 200 ohms
Signal-to-noise: greater than 55 dB

It was not a budget item. An Audio ad (March 1961, p.39) sold the C-37A for $295, including the power supply and carrying case; a 1957 new-product report had listed $300 with case. By April 1971 the model had been succeeded by the C-37P, an improved version with a new low-noise FET amplifier (Recording Engineer, April 1971, p.31). The comparison figures from that announcement say a good deal about the original: the 37A's self-noise was 34 dB SPL equivalent, its overload point 134 dB SPL.

Collector Jim Webb, whose C-37A was featured in that 1994 profile, called the sound very flat with low distortion. He estimated its value at $400 - $800. Beyond those period mentions, the archival record for the 37A is thin.