Shure SM33
A super-cardioid ribbon built for broadcast booths, with a low-frequency switch that lets you dial back the room.
Overview
The SM33 is a compact, rugged unidirectional ribbon microphone. Shure's own documentation describes it as combining wide-range response with a super-cardioid pattern. Super-cardioid is more directional than a conventional cardioid, which is what you want in a studio or broadcast booth where surrounding noise and reverberation are the problem. Shure pitched it for broadcasting, recording, and critical sound reinforcement. The feature list backs that up: adjustable low-frequency response via a selector switch, a built-in shock mount, and a mechanical design meant to survive daily use.
The ribbon element covers 40 to 15,000 Hz. That bottom end is generous for a ribbon of this class, and the top end stops short of the sizzle some condensers chase. The dual impedance arrangement is the practical detail for mating it to a system. The mic ships connected for 150 to 250 ohms, but it can be strapped for 30 to 50 ohms. In the 150-250 ohm configuration, open-circuit voltage at 1 kHz is -81.0 dB (0.089 mV) with a power level of -58.5 dB. In the 30-50 ohm configuration those figures are -87.0 dB (0.049 mV) and -60.0 dB respectively. The EIA microphone rating is -152.5 dB either way.
Physically, this is a working tool, not a display piece. It weighs 1 lb 10 oz (736 grams), heavy enough to feel substantial on a stand and light enough to boom. The finish is textured light and dark gray enamel. The self-adjusting swivel tilts the head 45° forward and 70° backward. The shock mount uses a live rubber vibration isolation unit to keep stand-borne rumble out of the ribbon. The connector is an XL-3-12 inside the microphone, and the supplied cable is 20 ft of two-conductor shielded wire with a Cannon XLR-3-11-C connector attached at one end. The part number is 124 0032 533.
A Shure advertisement running in Recording-Engineer (June 1972, p.36) quoted A&M Records' director of recording, Larry Levine, describing the SM33 ribbon as a regular in his sessions alongside the SM57 and 545 dynamics. The same ad copy reappeared in Recording-Engineer (April 1973, p.54). The "Series M33" phonograph cartridge advertising that ran in Audio (September 1962, p.68) and High-Fidelity (October 1962, p.19) is a different product entirely. It's a cartridge, not this microphone.
Shure's own catalog listings put the SM33 at $129.00. That sat above the SM50 at $75.00 and the SM300 at $90.00, and below the SM5A and SM5B at $225.00 each.
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