Keeley Bassist Limiting Amplifier

A New Generation of Keeley Compressors Focused on Fidelity

The Bassist Limiting Amplifier marks a clear evolution in the Keeley compressor family. While some previous designs relied on circuits like the CA3080 or LM13700 (often more "effect" oriented, more colored depending on settings), the Bassist adopts a modern VCA architecture based on the THAT Corp. 4320, with one philosophy: preserve the natural grain of the instrument while offering dynamic control worthy of a rack unit.

The result is a compressor designed to remain "invisible" when desired, yet capable of becoming a true tool for peak protection and control when used as a limiter.

For Which Musicians and Instruments?

The Keeley Bassist is aimed at guitarists and bassists who want tighter dynamics without losing attack, punch, or definition, including those with active preamp basses or high-output setups. It is also well suited for keyboards, drum machines, and any mono source that benefits from clean peak control.

In the studio, it facilitates recording by stabilizing levels before an interface or amplifier. Live, it provides consistency (slap, funk, pop, rock, country) and can serve as a "safeguard" against peaks that trigger unwanted distortion or strain speakers.

Simple Controls, Remarkably Effective Limiter Behavior

With three knobs, the Bassist goes straight to the point. Threshold sets the level at which compression kicks in: adjust it to catch only peaks or, conversely, to compress nearly the entire performance. Compression determines the intensity of processing above the threshold, from a natural leveling effect to a firmer limiter mode (high compression). Gain adjusts the output level for volume recovery (make-up gain) or to drive an amp/next pedal.

Its True RMS detector and feed-forward style behavior provide very coherent action, with attack and release times adapted to the signal: practical for maintaining a natural playing feel without manually setting attack and release. A dual-threshold LED indicator helps visualize when and how the compressor is working, ideal for quick adjustments on stage.

Sound Character

The Keeley Bassist's sonic character is primarily transparent : minimal coloration, controlled dynamics without exaggerated "pumping," and a clarity that respects pickups, preamps, and amplifier response. Its wide bandwidth above 20 kHz helps preserve harmonics, pick attack, and bass definition without muddiness.

Set to moderate compression, it delivers a more "grounded" and consistent performance, perfect for professional clean or light crunch tones. Pushed into limiter mode, it can tighten slap, funk, or highly percussive muted notes while remaining clean and quiet.

Technical specifications

Effects	Compressor	Type	Mains or battery
Technology	Analog	Use	electric bass, electric guitar
Format	Pedal	Color	Grey

Adjustments	Compression, Threshold, Gain	Typical release times	8 ms (1 dB), 40 ms (5 dB), 80 ms (10 dB), 160 ms (20 dB), 240 ms (30 dB)
Threshold indicator	dual LED	Input	6.35mm mono jack
Bandwidth	above 20 kHz	Output	6.35mm mono jack
Noise	-95 dBV	Bypass	true bypass
Total harmonic distortion	0.1%	Dimensions	112 x 68 x 51 mm
Maximum output gain	+30 dB	Weight	277 g
Input impedance	1 Megaohm	Power supply	9V DC (center negative)
Output impedance	100 ohms	Consumption	15 mA
Typical attack times	15 ms (10 dB), 5 ms (20 dB), 3 ms (30 dB)