Relab Development 176 Tube Compressor/Limiter - ESD

The Relab Development 176 Tube Compressor/Limiter is a meticulous software recreation of a classic 1960s 176-style valve compressor, modelled from the entire analogue circuit in real time. Every tube, transformer, timing network and power supply interaction has been captured, giving you the tone, timing and dynamic behaviour of the original hardware in a modern plug-in format.

Rather than simply emulating the controls, the 176 is built around a fixed-threshold, variable-gain design where ratio, drive and source material all interact to shape the compression curve and harmonic content. Add in polarity-selective detection, switchable interstage coupling and powerful calibration tools, and you have a mix-ready compressor that can move from smooth levelling to punchy limiting while staying musical and responsive to your audio.

Whether you are taming vocal peaks, adding weight to drums or gluing a mix bus, the Relab 176 gives you authentic valve character with a level of control and recall that is only possible in the digital domain. It is designed for producers and engineers who want the sound of a prized vintage unit, but with the flexibility to fine-tune bias, harmonics and transient response to perfectly suit each track.

Hardware-Accurate Valve Tone

The Relab 176 is driven by a real time circuit solver that models every stage of the original 176-style compressor, including tubes, transformers, RC timing networks and power supply behaviour. This means the plug-in responds to level, transients and programme material just like the hardware, delivering the same rich harmonics, saturation and dynamic feel that made the original a studio favourite.

Musical, Programme-Dependent Compression

Following the original fixed-threshold topology, the 176 uses four selectable ratios that each alter the knee position and slope. Combined with programme-dependent attack and release derived from true RC-tube interaction, the compression naturally adapts to the music. The result is nuanced dynamic control that can stay transparent on vocals and acoustic sources, or become assertive and punchy on drums and mix buses when pushed.

Deep Control of Transients and Harmonics

Advanced features such as Sidechain Polarity selection and Stage Coupling switching let you precisely tailor how the compressor reacts to different parts of the waveform. You can clamp aggressive transients while preserving body, choose between transformer or resistor coupling for faster or more vintage-feeling attack, and use the Calibration and back-panel trims to shift bias, threshold and harmonic balance for anything from warm levelling to tight, modern punch.

Studio-Ready Workflow in Any Modern DAW

Available in AU, VST3 and AAX formats for both macOS and Windows, the Relab 176 integrates seamlessly with most contemporary DAWs. iLok account authorisation keeps your licence secure, while Apple Silicon and modern Intel or AMD CPU support ensures smooth real time performance. With hardware-style controls, extended calibration options and instant recall, it brings classic valve compression into a fast, flexible digital workflow.

• Full Circuit Modelling of a 1960s 176 Compressor - Every tube stage, transformer, timing network and power supply interaction is recreated using a real time circuit solver, preserving the original unit's tone, timing and dynamic behaviour for authentic analogue-style compression inside your DAW.
• Ratio-Driven Knee and Programme-Dependent Timing - Four classic ratios (2:1, 4:1, 8:1 and 12:1) each change the knee position and slope, while RC-tube based attack and release adapt to signal level and transient content. This gives you smooth levelling at low ratios and powerful limiting at higher settings, all while remaining musical and responsive.
• Polarity-Selective Detection and Switchable Stage Coupling - Sidechain Polarity lets you choose whether the detector responds to positive, negative or both halves of the waveform, ideal for targeting specific transient edges. The Stage Coupling switch offers transformer or resistor paths between stages, so you can opt for ultra-fast attack and subtle tonal shaping, or slower, flatter response with vintage low-frequency thump.
• Advanced Calibration and Bias Controls - A global Calibration control shifts internal tube bias, threshold and harmonic profile in one move, while the back-panel trim pots for 6BC8 bias, 6BC8 anode balance, 12AX7 bias and Reference Level allow you to fine-tune harmonic mix, transient smoothness and low-frequency stability, mirroring the tweakability of the original hardware with modern precision.

General

• Product Type: Tube compressor/limiter plug-in
• Model: Relab Development 176 Tube Compressor/Limiter
• Format: ESD (Electronic Software Download)
• Authorisation: iLok account (dongle optional)

Audio & Processing

• Design: Fixed-threshold, variable-gain compressor
• Ratios: 2:1, 4:1, 8:1, 12:1
• Timing: Programme-dependent attack and release from RC-tube interaction
• Controls: Ratio, drive, Calibration, Sidechain Polarity, Stage Coupling, Fixed/Auto release
• Advanced Trims: 6BC8 bias, 6BC8 anode balance, 12AX7 bias, Reference Level (accessed via Relab logo)
• Circuit Modelling: Real time solver modelling tubes, transformers, timing networks and power supply interaction

Mac Requirements (64-bit)

• Operating System: macOS 10.15 (Catalina) or higher
• CPU: Apple Silicon M1 or newer
• RAM: 8 GB minimum, 16 GB or more recommended
• Plug-in Formats: AU, VST3, AAX (64-bit)
• Authorisation: iLok account (dongle optional)

Mac Compatible Hosts

• Pro Tools: 2020.11 and up (AAX 64-bit)
• Cubase: 9.5 and up (VST3 64-bit)
• Nuendo: 8 and up (VST3 64-bit)
• Ableton Live: 10 and up (64-bit)
• Reaper: 7 and up (64-bit)

Windows Requirements (64-bit)

• Operating System: Windows 10 and up (64-bit)
• CPU: Intel Core i7 (8th generation or later) or AMD Ryzen 5 (3000-series or later) with AVX2 support
• RAM: 8 GB minimum, 16 GB or more recommended
• Plug-in Formats: VST3, AAX (64-bit)
• Authorisation: iLok account (dongle optional)

Windows Compatible Hosts

• Pro Tools: 2020.11 and up (AAX 64-bit)
• Cubase: 9.5 and up (VST3 64-bit)
• Nuendo: 8 and up (VST3 64-bit)
• Ableton Live: 10 and up (64-bit)
• Reaper: 7 and up (64-bit)