Classic Compression For Modern Players
Compression is an essential tool on any bass player’s pedalboard. Today, we have access to incredible options like the Origin Effects Cali76 or the Empress Bass Compressor. But things weren’t always this advanced, and today, I want to talk about one of my favorite compressors of all time—the Boss CS-2 Compressor Sustainer.
The Boss CS-2 is not a flashy pedal. It lacks the dedicated fine-tuning controls found in modern compressors. It’s not a compressor/limiter; rather, it’s a compressor/sustainer.
A compressor/limiter is designed to prevent peaks from exceeding a set threshold, acting as a hard stop to control volume spikes. It typically has a high ratio (10:1 or more), making it ideal for keeping levels consistent and preventing sudden jumps in volume.
A compressor/sustainer, on the other hand, smooths out dynamics without completely limiting peaks. It reduces the difference between loud and soft notes, ensuring a more even output while adding sustain. This type of compression is often used to enhance note clarity and sustain in both guitar and bass setups.

My personal Boss CS-2
Understanding the CS-2 Through Its Manual
Since I lost the box for my personal CS-2 long ago, I searched the internet for a copy of the original manual. Given that the pedal was released in 1981, I thought it would be interesting to look at what Boss originally said about its design and function.
According to the manual:
“CS-2 is a low-noise type effect providing long sustain with attack volume. It can adjust picking force widely and provides any drive sounds. As having a wide range of maximum input level and compression, it can be used for any electronic musical instruments. In addition, CS-2 can be used for an ordinary limiter by turning down sustain volume.”
Not the clearest explanation, I know! But let’s break it down.
How the Boss CS-2 Works
The CS-2 compresses louder signals and boosts softer signals, resulting in a more balanced output. At the same time, it extends note sustain, making them ring out longer. When combined, these two functions create a smoother, more controlled sound that enhances a player’s dynamics.
CS-2 Controls
The CS-2 features a simple three-knob layout:
- Level – Adjusts the output volume to compensate for the compression’s effect on signal level.
- Attack – Controls how quickly the compression engages, affecting the intensity of each note’s transient.
- Sustain – Adjusts the length of sustain. When turned counterclockwise, it increases compression, effectively limiting the output level.
The Sustain control is particularly interesting. The manual states:
“The sustain control provides adjustment to the compression range. When set at the full clockwise position, sustain is longest. When turned counterclockwise, compression increases, allowing the unit to limit the output level. This is particularly useful for adding punch to a guitar, bass, or electric piano.”
The CS-2 in Action
Over the years, bassists like Juan Alderete and Janek Gwizdala have been known to use the CS-2. While it can be somewhat noisy compared to modern compressors, its characteristic warmth and harmonic enhancement make it a favorite among players looking for a smooth yet punchy tone.
So, why does the CS-2 sound so unique?
Essentially, it rolls off some of the high frequencies, which results in a warmer and smoother tone. This tonal character likely comes from its analog circuitry and specific component choices, as the newer CS-3 does not have the same sonic qualities. The CS-3 is cleaner and more transparent, but many players still prefer the CS-2’s coloration.
Conclusion
The Boss CS-2 is a true classic that has stood the test of time. Used by bass legends, it’s a go-to pedal for those looking to enhance their tone, add sustain, and smooth out their dynamics. It’s not a transparent compressor—it has a distinct character that adds warmth and thickness to your sound. While it’s not the quietest pedal out there, it shines in rock, funk, and live settings where its punch and sustain truly come alive.
If you’re after a compressor that adds musicality rather than simply controlling levels, the CS-2 is a fantastic choice.