40D

Common name: Shure 40D

Production Status: Discontinued / Vintage

The 40D is an omnidirectional “bottle styled” condenser microphone for universal applications. The head of the microphone can be aimed directly at the sound source for optimal pickup whether the microphone is placed on a table, without a stand, suspended from the ceiling or mounted on a stand. This is especially useful in overhead pickups in broadcasting, public address and sound picture recording applications. The capsule features an air-damped stretched diaphragm and a two-stage amplifier using type 30 valves. It has excellent frequency response characteristics thanks to correct diaphragm stretching and and a special backplate that controls the damping. The air valve equalises the steady-state air pressure on both sides of the diaphragm to maintain constant sensitivity and frequency response under a wide range of atmospheric conditions. The microphone requires 6 volts at 60 M.A. and 180 volts at 3 M.A. from batteries or 41A power supply. Special terminal strip, accessible in tube compartment, provides either 200 or 50 ohm output. The 40C has a cast aluminum case, finished in baked rubber-black japan. The head housing the capsule is chromium plated. Includes 12 feet (3.66 meters) of shielded, rubber-covered cable, tube and special chromium plated suspension adapter. The threaded base allows mounting on standard Shure desk stand, or floor stand.