VCL-4
by Fuse Audio Labs · Compressor · Vintage opto leveler emulation
Not rated yet
VCL-4 emulates the silver-face revision of the op-amp-based successor to a classic late-1960s opto leveler.
Fuse Audio Labs rebuilt the circuit on stripboard to model it, and it adds a switchable ratio, for $59.
Best for: Vocals, Bass, Guitars, Mix Bus. Genres: all genres.
Keywords: opto, hardware emulation, op-amp, smooth, vintage, bass, classic, extreme, simple, vocals, electric guitar, transformer, 60s, bus processing, circuit-modelled, colored, full mix, gentle, heavy, mix bus, mixing, modern, musical, sidechain input, single-band.
What it does
VCL-4 is "a faithful emulation of the silver face revision" of a classic op-amp opto leveler. It gives program-dependent optical compression, from unobtrusive to extreme, with simple controls.
- Circuit model: the receiver stage, side-chain, Vactrol LED driver and output transformer are all modelled.
- Hardware rebuild: Fuse Audio Labs rebuilt the original circuit with modern Vactrols in place of the vintage LED/LDR cells, to model it accurately.
- Program-dependent response: the optical cell reacts to the material, for smooth, musical levelling.
- Switchable ratio: covers gentle levelling through to heavy, extreme compression, so it adapts to different sources.
- Saturation: the modelled output stage adds colour as you push it.
The current version is 2.7, and a demo is available.
Source: Fuse Audio Labs product page
When to use it
VCL-4 is the opto pick when you want smooth levelling with more range than a single-mode opto. Compared with Universal Audio's Teletronix LA-2A Leveler Collection and Waves CLA-2A, which model the tube original, it models a later op-amp design, and its ratio switch lets it go from subtle to extreme. Compared with FabFilter Pro-C 3's opto style, it has far fewer controls, but its modelled circuit and output transformer add more saturation.
- Best for: smooth levelling on vocals, bass, guitars and buses, with a touch of saturation.
- Genres: any style.
- Look elsewhere if: you need fast transient control; an FET compressor like the 1176 Classic Limiter Collection or CLA-76 is better for that.
What producers say
User feedback is small but very positive, centred on its saturation and simplicity.
- KVR users rate it 5 out of 5 from one review (2025), which called it a "first grab" opto leveler and praised its saturation and ease of use.
Where to buy
- Fuse Audio Labs: $59
Tutorials and reviews
- Fuse Audio Labs VCL-4 Review Urei LA-4 Compressor Plugin
- A Plugin Worth Checking Out ( Fuse Audio Labs ) VCL-4
- Fuse Audio Labs - VCL-4 - Insight (no voiceover)
- VCl-4 Overview and review In The DAW
- Fuse Audio Labs VCL-4 -Revisión Oficial en Español-
Similar plugins
- VLA-3A by Black Rooster Audio · LA-3A-style opto compressor · $59
- Teletronix LA-3A Classic Audio Leveler by Universal Audio · Opto compressor · $29
- CLA-3A Compressor / Limiter by Waves · Opto compressor · $29.99
- EA-3A by Echelon Audio · Solid-state opto compressor · $39
- VLA-2A Mark II by Black Rooster Audio · LA-2A-style opto compressor · $59
- Teletronix LA-2A Leveler Collection by Universal Audio · Opto (tube) · $29
- SD-3A by Slate Digital · Opto leveling amplifier · $99
- White 2A Leveling Amplifier by IK Multimedia · Opto compressor · $79.99
- bx_opto by Brainworx · Optical compressor · $100
- Opto-2A by Antelope Audio · LA-2A-style opto compressor · $14.90
More from Fuse Audio Labs
- Bucket-500 by Fuse Audio Labs · Delay · $49
- Dozer-Drive by Fuse Audio Labs · Distortion · $19
- DrumsSSX by Fuse Audio Labs · Restoration · $35
- F-59 by Fuse Audio Labs · Amp Sim · $59
- Flywheel by Fuse Audio Labs · Saturation · $59
- OCELOT Clipper by Fuse Audio Labs · Clipper · $69
- OCELOT Limiter by Fuse Audio Labs · Limiter · $69
- OCELOT Octaver by Fuse Audio Labs · Pitch & Tuning · $69