The Crazy Tube Circuits Phi (φ) is a versatile, all-analog multi-mode compressor pedal that now offers three distinct compression circuits, selectable via a toggle switch. Each circuit is completely independent, with its own character, response, and compression style, allowing players to tailor the feel and dynamics to suit any instrument or playing approach.

At the heart of the pedal is a smart internal switching system that gives you a wide compression ratio range—from subtle leveling at 1:1 to limiting at 20:1. Whether you're looking for smooth, transparent control or dramatic dynamic shaping, Phi adapts effortlessly.

The FET mode is based on a feedback-style compression circuit that uses a FET transistor for gain reduction. It’s capable of super-fast response times and adds a distinctive tonal color, along with a touch of musical harmonic content, especially when pushed.

The OTA mode is a punchy, feed-forward compression circuit, commonly found in most guitar compressors. This version offers excellent control and is designed to catch fast transients effectively, making it perfect for aggressive playing or limiting applications. It delivers a direct, tight sound with a strong sonic footprint.

The Optical (OPTO) mode uses a hand-selected photocell and a feedback detector to produce organic, natural compression with smooth attack and release characteristics. It can be extremely musical even at high settings, or dialed in so transparently that you may not notice it's on—until you turn it off.

Phi also includes parallel compression, allowing you to blend the compressed signal with your original dry tone. This technique preserves clarity and articulation while adding depth and sustain—ideal for maintaining dynamics in both studio and live environments.

Internally, you can switch between 9V or 18V operation from a standard 9V DC power supply. The 18V setting increases headroom, giving the pedal a wider dynamic range and an even more refined compression feel.

With low noise, full frequency response, and enhanced clarity, Phi is equally at home on guitar, bass, or virtually any instrument. Whether you're on stage or in the studio, it delivers pro-level compression in a compact and flexible format.