Sennheiser MD403

The MD403 is a small, compact dynamic microphone that was considered to be of high quality. It was sold widely with tape recorders under various labels including Dual and Harting, as well as Sennheiser's own Labor-W brand. They were made in large quantities and are still desirable to this day. The capsule is similar but not identical to the later MD409.

It was designed to be used either on the desk or on a larger stand, and as such has both a fold-down support and a recessed 3/8" threaded insert.

The MD403 appears in the German language Funkshau magazine in 1957, and in the British Hi-Fi yearbook in 1965, so was certainly in production throught this period, if not longer.

Translated from an advertisement for the MD 403 in Funkshau magazine in 1957...

"It’s in your hands....whether or not your customers enjoy using their tape recorder. Even the best device cannot reproduce more than what the microphone originally captured. If the goal is to make high-fidelity home recordings, you can confidently recommend the MD 403 directional microphone. Thanks to its exceptionally smooth frequency response and favourable directional characteristics, this robust moving-coil microphone enables high-quality recordings—even in acoustically untreated rooms—that captivate the listener with their true-to-life sound.

Frequency response up to 12,000 Hz (±3 dB), with the target curve rising gradually by 5 dB starting at 1,000 Hz. Sensitivity: approx. 0.15 mV/µbar for the 200 Ω version; approx. 2.2 mV/µbar for the 45 kΩ version."

See the 1963 Sennheiser catalogue at the Echshall website.