The UREI LA-3A is an iconic half-rack electro-optical leveling amplifier that bridged the gap between two legendary compressor architectures: the smooth, program-dependent optical curve of the tube-driven Teletronix LA-2A and the lightning-fast, mid-forward punch of the solid-state UREI 1176. Introduced in 1969 as the transistorized successor to the LA-2A, the LA-3A retains the famed T4B optical cell but pairs it with an all-solid-state, transformer-coupled FET amplifier stage.

The result is a compressor with a singular sonic signature. It offers faster attack and release responses than an LA-2A, allowing it to grab fast transient peaks while maintaining the fluid, non-pumping leveling that optical circuits are known for. Famous for bringing mid-range sources—especially electric guitars, snare drums, and lead vocals—straight to the front of a mix with aggressive clarity and dynamic density, the vintage LA-3A remains one of the most sought-after tracking and mix tools in recording history.

The UREI LA-3A is a legendary hybrid of optical leveling and solid-state punch. If you want the smooth, effortless compression of an LA-2A paired with the aggressive mid-range bite and transient speed needed for modern rock electric guitars and vocal tracking, the LA-3A is an irreplaceable centerpiece in any top-tier analog outboard rig.

Judging by the front panel and serial numbers (3468, 3526) this unit appears to have been manufactured sometime between the mid 70's and 1981.

The UREI LA-3A Audio Leveler is an all-solid-state electro-optical attenuator and leveling amplifier designed to provide smooth, low-distortion automatic gain control for broadcast, recording, and sound reinforcement applications. Introduced as the transistorized successor to the famous vacuum-tube LA-2A, the LA-3A retains the unique optical attenuation characteristics of its predecessor while offering a significantly faster response time, improved high-frequency performance, and higher efficiency in a compact, half-rack package.

At the heart of the LA-3A is the proprietary T4B electro-optical attenuator assembly. This light-sensitive cell acts as a program-dependent variable resistor, automatically governing dynamic compression with smooth, natural attack and dual-stage release times. By eliminating the high noise floors and heat generation associated with tube circuitry, the LA-3A’s discrete, transformer-coupled solid-state amplifier circuit delivers exceptionally clean, low-distortion amplification with instantaneous transient recovery.

The LA-3A provides maximum operational simplicity with two main front-panel controls: Gain and Peak Reduction. A two-position front-panel switch allows the unit to operate as either a smooth Compressor (approximately 3:1 ratio) or a fast, protective Peak Limiter (infinity:1 ratio). Designed for rigorous commercial use, two LA-3A units can be mounted side-by-side in a standard 19-inch equipment rack using an optional rack-mount coupling kit, while a rear-panel stereo link connection allows phase-coherent operation across two units for stereo program material.

Key Features

• T4B Electro-Optical Attenuator: Proprietary optical cell delivers smooth, program-dependent compression and limiting without pumping or breathing.

• All-Solid-State Circuitry: Transformer-coupled discrete transistor design provides low distortion, high reliability, and fast transient response without tube heat or aging.

• Dual Operating Modes: Rear-panel mode switch selects between subtle Compressor mode (3:1 ratio) and aggressive Limit mode (infinity:1 ratio).

• Half-Rack 2U Footprint: Space-saving enclosure allows two units to be mounted side-by-side in a standard 2U 19-inch rack slot.

• Stereo Interconnection: Rear-panel terminal strip allows simple interconnect wiring to link gain reduction circuits on two LA-3A units for stereo bus operation.

• Large Illumination VU Meter: Illuminated VU meter switchable between Output Level and dB Gain Reduction monitoring.