The Shure Level-Loc is a vintage audio level controller introduced in 1968, designed to deliver smooth, intelligible, and uniform sound in a variety of public address and recording scenarios. It operates as a transistorised variable gain amplifier that instantly reduces excessively loud input signals by as much as 100 times, without significant distortion. This makes it especially effective for controlling erratic microphone use common in live speaking situations, including close-up shouting, bobbing and weaving, or multiple speakers with differing vocal levels.
Equipped with a “Sound Control Zone,” the Shure Level-Loc allows users to define a consistent pickup range using a Distance Selector Switch calibrated for 6, 12 or 18 inches. Within this zone, audio levels are automatically modulated, eliminating blasting and fluctuations in volume. The result is a steady and listener-friendly output, regardless of speaker movement or microphone proximity.
Ideal for paging systems, supermarket announcements, round-table discussions, seminars, and even interviews, the Shure Level-Loc also found use in recording applications. It proved useful for tape recording by limiting loud bursts and maintaining consistent levels during dramatic speech or unpredictable vocal performances. Though it does not increase quiet signals, it controls overly loud ones, making it a favourite for its predictable compression behaviour.
Power is supplied by an internal 9V battery or an external DC source such as the Shure M68 mixer. The unit can be bypassed entirely using a dedicated switch, making it versatile for systems requiring temporary compression control.
While originally intended for public address applications, the Shure Level-Loc gained cult status among engineers and producers in later decades for its aggressive compression character, becoming a secret weapon on drums and other dynamic sources in studio environments. The later model pictured here added a level control.
Features
- Automatic level control with transistorised variable gain amplifier
- Instant signal reduction up to 100 times for loud inputs
- Prevents close-up blasting, fadeouts, and feedback build-up
- Distance Selector Switch for 6, 12 or 18 inch control zones
- Bypass switch for normal microphone signal routing
- Battery powered or externally powered via Shure M68 Mixer
- Useful in live PA, paging, meetings, interviews, and recording
- Legendary as a studio compressor for its aggressive tone
