Crazy Tube Circuit Golden Ratio Phi V2

Crazy Tube Circuit‘s Golden Ration Phi V2 updates the Greek company’s flagship compressor by shrinking it into a compact case and adding an extra compression mode, for a total of three: FET, Opto and OTA.

Here’s what each mode does to your signal:

FET uses a FET transistor for gain reduction and adds distinctive color to the signal and can be extremely fast in it’s attack/release response, but it can add some unwanted saturation to your tone.

OTA is a very common technology for guitar compressors: it “squeeze” your signal more heavily and it’s ideal for catching fast transients and limiting (perfect for a funky rhythm guitar).

OPTO is an Optical compressor based on a photocell combined with a feedback detector circuit. Like some classic studio units like the LA2A, it offers a musical (but slower) attack and release and sounds natural even at extreme settings.

The Ratio knob allows you to apply compression from 1:1 (no compression) to 20:1 (the peaks above the Threshold level get squashed by 20 times). Separate knobs for Attack and Release allow for precise control over the dynamics, while the always useful Blend knob lets you reintroduce some of the clean signal to achieve what’s commonly referred to as “parallel compression.”

Hear the Crazy Tube Circuit Golden Ratio Phi V2 in action in the videos below.


? (Phi) has been updated to include 3 separate compressor circuits at a flip of a toggle switch.

An internal smart switching circuit lets you decide which type of compression works best for you featuring a wide range of compression ratio from 1:1 to 20:1

Each all-analog circuit is totally independent and has its own voice with different compression characteristics, range and response of controls to suit every style.

FET compressor: This is a feed-back detector / control compression circuit that relies on a FET transistor for gain reduction. It adds a distinctive color to the signal and can be set for super-fast response, but it may also introduce a bit of musical distortion.

OTA compressor: The majority of guitar compressors use this technology. Our interpretation uses a feed-forward detector circuit thus being able to “squeeze” things harder, ideal for catching fast transients and limiting. It is the most controllable circuit with punchy and direct sound.

OPTO (Optical) compressor: A hand selected photocell combined with a feed-back detector circuit offer smooth attack and release characteristics resulting in very musical and organic compression even on extreme settings. It can also be set very neutral so that you won’t be able to tell when it’s on but you sure going to miss it when it’s gone.

Phi will fatten up your tone even with no compression added. With the parallel compression technique of blending the compressed signal with the original – uncompressed signal, you will experience clarity and precision only found in studio recordings.

An internal switch selects between 9 or 18V DC of operation from a standard 9V DC power supply via an internal voltage multiplier. Use the 18V setting for increased headroom and enhanced compression characteristics.

Features superb low-noise floor performance and full frequency response making it ideal for guitar, bass and virtually every instrument either on studio or stage.