The CS-550 Stereo Chorus was specially commissioned by the legendary Japanese rock guitarist Hisato "Char" Takenaka. After 25 years, Char had yet to find a chorus unit that met his exacting standards, so he turned to Maxon to create one. Char specified three key requirements for the design: it should generate less noise than the typical chorus unit, offer exceptional versatility, and be analog. The outcome was so successful that Maxon decided to release the unit commercially, and thus the CS-550 Stereo Chorus came into existence.

The CS-550 provides a wide spectrum of both classic and innovative chorusing effects. It is built around the Panasonic MN3207 (a now-discontinued low voltage BBD IC), and its Rate and Depth controls can produce a full range of chorus textures, from the understated to the intense. The specially calibrated oscillator circuit is capable of speeds that can convincingly replicate rotary speaker cabinets, and it offers just the right modulation depth for a rich vibrato without discomfort.

The CS-550's exceptional tone is largely due to its Delay Time control. This control has an inverse relationship with the delay time and the frequency shift of the chorus effect: as the delay time is increased, the frequency shift decreases. This relationship results in "double level" and "cancellation" peaks and notches at specific frequencies, yielding a highly realistic, three-dimensional chorus effect. Moreover, the Delay Time control interacts with the Rate and Depth controls, expanding the Delay Time range as the Depth is increased, and altering the Delay Time more rapidly as the Speed is increased.

Adding to its versatility, the CS-550 features stereo outputs for mono, stereo, or inverted mono signal routing. The level of the effect signal relative to the dry signal can be adjusted via a Mix Level control located on the rear of the unit, making the CS-550 an ideal choice for bass guitars as well.