Api Audio Tranzformer CMP

A Historic API Circuit, Featured in the Select TranZformer Range

API is one of the essential signatures of VCA compression: fast, controlled, and capable of "holding" a signal without crushing it when settings are properly adjusted. With the Select TranZformer series, the brand translates a high-end analog processing approach into a compact format designed for the pedalboard. The CMP positions itself as a compression pedal with a strong character that goes beyond simply leveling: it can also shape attack, sustain, and density, notably thanks to its transformer output.

Who It's For and Where the CMP Makes a Difference

The Select TranZformer CMP is aimed at guitarists (and more broadly any Hi-Z instrument source) who want a more "technical" compression than a traditional pedal, without losing the simplicity of immediate adjustment. It is ideal for stabilizing cleans, adding sustain without excessive pumping, or controlling a very wide dynamic range (funk, country, arpeggios, slide, pop rhythm) while maintaining expressive playing.

In the studio, it naturally integrates into a "direct input" chain: compression can be used to secure transients, even out pick attack, or thicken a guitar before a drive stage. On stage, the blend helps preserve attack and clarity, making the CMP particularly effective in front of an amp already sensitive to level variations.

Controls and Character: Precision Compression from Modern to Vintage

Feed-forward or Feed-back: Two Responses, Two Feelings

The type selector lets you choose between feed-forward ("New") and feed-back ("Old") behavior. In practice, feed-forward mode tends to offer a more direct and transparent action, often perceived as more "modern": perfect for tight rhythms and highly controlled levels. Feed-back mode provides a smoother, more organic response, with a sound often described as more "vintage" and musical, very interesting for retaining movement and less upfront compression.

Attack, Release, and Blend: Sculpting the Groove Without Losing the Original Signal

The switched attack and release times get straight to the point: you quickly choose whether compression should catch the transient (fast attack) or let more punch through (slow attack). The same logic applies to release to avoid pumping effects or, conversely, to achieve longer sustain. The wet/dry blend is a major asset: you can enhance sustain and control dynamics while preserving the bite and definition of the uncompressed signal.

API Transformer Output: Density and "Console" Finish

Where many pedal compressors remain purely utilitarian, the CMP adds a dimension of character thanks to its API output transformer. It can help provide a sense of a more "finished" signal, more solid in the mix, with a touch of analog grit. This is also what sets the CMP apart from many standard compressors: it's not just about level control but also about sonic signature.

Technical specifications

Effects	Compressor	Type	sector
Technology	Analog	Use	electric guitar
Format	Pedal	Color	Blue

Selectable compressor types	feed-forward / feed-back	Power connector	2.1 x 5.5 mm
Ratio (sustain)	varies from 1:1 to 20:1 depending on compressor control setting	1 Hi-Z instrument input	6.3 mm TS
Attack (switched)	fast (1 ms) or slow (10 ms)	1 output	6.3 mm TS
Release (switched)	fast (300 ms) or slow (1 s)	Dimensions	116 x 96 x 76 mm
Type (switched)	New (feed-forward), Old (feed-back)	Weight	0.79 kg
Input gain control	variable from 9 dB to 30 dB