Calibration, Meter Zero Adjust

Calibration

Meter Zero Adjust

The zero-adjust of the meter is set by the screw-adjust potentiometer located next to the Limit / Compress Switch. To adjust this, put the meter into Gain Reduction mode. Make sure that there is no signal present. Loosen the locking nut and use a screwdriver to adjust this potentiometer until the meter reads zero.

Side-Chain Pre-Emphasis (R37)

The LA-2A was designed for use in broadcast applications. The audio signal in FM broadcasting undergoes pre-emphasis and results in a 17 dB boost at 15 KHz. Due to this increase in signal level, transmitters are subject to over-modulation. The LA-2A provides a control (R37) which controls the amount of high-frequency compression.

This potentiometer is factory set for a “flat” side-chain response (clockwise). Increasing the resistance of this potentiometer by turning it counter clockwise will result in compression which is increasingly more sensitive to the higher frequencies.

Stereo Balance Adjust (R3)

For stereo operation, two LA-2A units are interconnected in order to achieve the same amount of gain reduction from each of the two units to maintain stereo imaging. In order to accomplish this, terminals 6 from each unit should be connected together. Additionally, their grounds (terminal 7) should be connected together.

The interconnecting wire should be less than 2 feet in length and should be shielded. The shield should be used to connect terminals 7 from each of the units together.

To calibrate the units for stereo operation:

!Connect the units together as described previously.

!Turn the Peak Reduction knob counterclockwise (no compression).

!Set R3 on each unit to a clockwise position.

!Set each meter to read Gain Reduction.

!Adjust the Peak Reduction control on the left channel until approximately 5dB of gain reduction is achieved.

!Adjust R3 on the unit that shows the greatest amount of gain reduction until the gain reduction indications are equal.

!When operating, set the Peak Reduction controls to the same setting on both channels.

LA-2A specifications

The Inova LA-2A is a sophisticated optical compressor renowned for its classic design and exceptional sound quality. Hailing from the lineage of legendary optical compressors, the LA-2A combines vintage warmth with modern reliability, making it a staple in professional recording studios globally.

One of the main features of the LA-2A is its opto-electronic gain reduction circuit, which utilizes a light-dependent resistor (LDR) and a sealed optical element to achieve compression. This unique mechanism provides a smooth and transparent compression, allowing the audio signal to maintain its natural dynamics while controlling peaks effectively. The optical design contributes to a musical response, widely regarded as one of its defining characteristics.

The LA-2A also features a simple and intuitive interface. It includes essential controls such as Peak Reduction, which adjusts the level of gain reduction, and Make-Up Gain, which compensates for any lost level after compression. The device typically has two modes: the Compress mode for moderate compression and the Limit mode for more aggressive limiting. This flexibility makes it suitable for a variety of audio sources, from vocals to instruments.

Another noteworthy characteristic is its true tube circuitry. The LA-2A employs a vacuum tube in its audio path, contributing to its warm tonal character. This tube coloration enhances the richness of audio signals, making the device particularly popular for vocals and bass, where presence and depth are paramount.

Additionally, the build quality of the LA-2A is exceptional. The chassis is constructed from durable materials, ensuring longevity and reliability in demanding studio environments. Its vintage aesthetic features analog VU meters, adding to its charm while providing visual feedback of the gain reduction.

Inova has modernized the LA-2A with contemporary features while preserving its classic sound. Enhanced technologies such as improved signal-to-noise ratio and updated component designs ensure that the LA-2A remains competitive in today's digital landscape.

Ultimately, the Inova LA-2A is a beautifully crafted compressor that delivers a unique sonic signature. It combines vintage appeal with modern functionality, making it an essential tool for audio engineers and music producers seeking to achieve professional-grade mixes. Its smooth compression characteristics, intuitive controls, and durable design are testaments to its lasting legacy in the world of audio processing.