stereo / dual mono Zener compressor/ limiter

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Gem Audio Labs Preceptor Model-T

The Preceptor model-T (Transparent) is a two-channel, class-A compressor/limiter. Gain reduction is handled by a discrete VCA design based on Zener diodes and bipolar transistors. There are 16 preciesly matched Zener diodes on board! The Gem Audio Labs Preceptor Model-T compressor/limiter looks right out of the early '70s. Its stepped knobs dole out satisfying clickage and its dual VU meters bathe your console in a warm yellow glow. Hand-built using premium parts, the Preceptor juices whatever you send its way with warmth and sheer size. A neutral-sounding compressor and somewhat aggressive limiter, the Preceptor is at home on tracks or perfect for your mix bus. It also performs excellent in the mastering suite. If you're looking for a versatile, great-sounding compressor / limiter, give Gem Audio Lab's Preceptor Model-T a try.

Inputs: Balanced XLR

Outputs: Balanced XLR

Ext. sidechain inputs: Balanced TRS

Signal transformers: Carnhill

Bypass: hard relay bypass

Input impedance: 2k5Ω or 10kΩ switched on the front panel

Output impedance: 50Ω

Frequency response: 20-22.000Hz

Maximum input level : + 21 dBu @ sensitivity +4 dBu

Maximum output level: +23 dBu

S/N ratio (A-weighted) : better than 85dBu

Meter: 0 to -20dB gain reduction

Signal path: Class-A, discrete

VCA: bipolar transistors biased by Zener diodes

Ratio: 2:1, Limit (Fairchild  660)

Action modes: hard, soft

Attack: 0,5ms – 31ms ( switched modes: fast, medium, slow)

Release: 50ms – 2s

External sidechain: YES

Sidechain filtering : OFF, 40Hz, 80 Hz, 120 Hz, 200 Hz, 320 Hz

Blender (parallel compression) : yes

PSU: internal

Fuses type: 230V : 630mA (slo-blo; 5x20mm) /115V :1,25A           (slo-blo; 5x20mm)

Power consumption: 70W

Dimensions (WxHxD) : 483x133mm (3U) x 245mm

Weight: 6,4kg


Subject to change without notice. 


Gem Audio Labs (Generic Audio) Preceptor compressor limiter review

Difference between Preceptor Model-A and Model-T

The Model-A has a “Speed” switch that affects Attack and Release times. On the Model-T, the switch affects Attack only (and is labelled as such).


The Model-T sports an additional switch (not present on the Model-A): “Action,” which lets you choose between two modes – each giving you a different combination of threshold and compression knee. “Soft” gives you less pump factor and is useful for for complex material – mastering, for instance. “Hard” allows for more agressive pumping and is great for tracking, when you occasionally want access to stronger compression.


The Model-T’s “Soft” setting is optimized for complex material that requires a more finessed touch, such as film scoring or classical music recording and mastering. In case your were wondering, the “T,” in Model-T designates “Transparent.” The Model-A (“Agressive”), lacking this switch, exhibits the “Hard” compression characteristic, and is great for more agressive material such as rock and pop recording and mastering.