FET compressor

The FET compressor is the fast, forward one. Its threshold is fixed, so you drive the signal into it with Input and the compression deepens as you push; Output brings the level back. The attack reaches down to a fraction of a millisecond, the release is program dependent, and the circuit adds a little harmonic grit that grows with the reduction. It is built from the published behaviour of the classic FET limiters, not as a copy of one unit.

When to use it

Reach for it on vocals that need to sit in front, on bass that should hold its place, on snare and room mics that want to explode, and in parallel on a drum bus. The plain Compressor is the transparent choice with a visible curve; the Stress compressor is the heavier character with distortion on tap; the Limiter is for a ceiling, not a sound.

Controls

Input and Output

Input drives the signal into the fixed threshold: more Input, more compression. Output restores the level afterwards. The link button between them is on by default, so turning Input moves Output the other way and a track peaking around −12 dBFS keeps its level while you dial in the squeeze. Unlink to set them independently.

Attack

How much of each hit gets through before the squeeze starts, on a 0 to 7 dial where 7 is the fastest. Below 1 the compression is off and only the amplifier colour remains.

Release

How quickly the level recovers, 1 to 7 with 7 fastest. The release also follows the material: quick after short hits, slower after sustained compression.

Ratio

Each button is its own circuit. 4 starts earliest with the softest knee and suits vocals and bass; 8 is firmer; 12 is near limiting; 20 limits with a hard knee. All is every button pressed at once: a lagging, overshooting attack, a cliff release and a distorted, explosive squash.

Revision

Black is the cleaner later circuit. Blue adds second harmonic, a softer output stage and a longer program-dependent release.

Mix

Blends the compressed signal with the untouched one inside the module, for parallel compression without a second track.

Tips

• Start at Ratio 4 with Attack and Release at 4, then push Input until the needle shows 3 to 6 dB on the loud notes. Only then try a faster attack.
• All with a slow attack on room mics is the classic exploding-drums sound; pull Mix down to keep the kit’s shape underneath.
• Fast attack and fast release on bass add odd harmonics inside each cycle. That is a tone, not a fault; use it or slow the release.