Summary

The Bus Processor 670 is a modern plugin emulating the legendary dual-channel variable-mu tube compressor, known for its warmth, weight, and musical compression characteristics. Developed by Softube, it delivers the distinctive sound of the vintage 670 hardware with added modern features like saturation control, spatialization, and sidechain options suitable for mixing and mastering workflows.

Features

• Dual-channel variable-mu tube compressor emulation with dynamic compression ratio responding to signal level
• Controls for tube and transformer saturation, plus a calibration knob affecting compression-dependent saturation
• Sidechain filters with control over filters, tone shift, mono/stereo linking
• Spatialization features including air band, mono maker, and stereo widening
• Separate outputs for Mid/Side processing
• Fully compatible with Softube's Console 1 Mixing System and Flow Studio hardware
• Included in Flow Mixing, Mastering, and Complete Suite subscriptions
• Designed for a modern workflow while retaining analog warmth and cohesion

Background

The original hardware unit, the 670 compressor, was produced in limited quantities (fewer than a thousand units), originally used as a mastering limiter for vinyl. It is famous for adding musical harmonic distortion and analog cohesion even at subtle settings and offers classic compression vibe from studios like Motown and Abbey Road. Softube’s version enhances this legendary sound with added flexibility and modern audio production needs.

Who is it for

This plugin is intended for audio engineers and producers seeking the classic analog tube compression sound of the 670 with extended modern controls for mixing and mastering applications in both native and hardware-integrated environments.