Boss CH-1 Guitar Effect

Boss CH-1 Super Chorus — Classic Stereo Modulation in a Compact Stompbox

The Boss CH-1 Super Chorus pedal has been a fixture on guitar and keyboard rigs since its introduction, prized for the clear, shimmering tone that defined the original BOSS chorus sound. This compact stompbox packs a stereo chorus circuit and a four-knob interface into the same rugged metal chassis used across the BOSS compact line. Many guitarists and keyboardists rely on this model for a dependable, easy-to-dial modulation effect that fits seamlessly onto any pedalboard.

What Sets the CH-1 Apart From Standard Chorus Pedals

Most single-output chorus circuits can't match the CH-1's ability to send discrete wet and dry signal paths through stereo OUTPUT A/B jacks, a design inspired by the Roland JC-120 Jazz Chorus amplifier's Dimensional Space Chorus topology. The dedicated EQ knob acts as a low-pass filter for the modulated signal, offering a sweep from warm and rounded at lower settings to bright and sparkling at higher ones — something rarely found on other chorus pedals.

Control Interface and Signal Flow

Shaping chorus texture is simple with the top panel's four dedicated controls. Rate sets modulation speed, Depth controls intensity, E.Level blends the effect with the dry signal, and EQ colours the chorus voice itself. When the effect is disengaged, buffered bypass keeps your tone intact, which matters if your pedalboard has long cable runs or several true-bypass units.

• Controls: EQ, E.Level, Rate, Depth — covering every chorus parameter you need, with no menu-diving required.
• Bypass: Buffered — preserves high-end and signal level, even in complex pedal chains.
• Connect any guitar, bass, or keyboard output using the standard 6.3 mm TS jack input.

I/O, Power, and Electrical Specs

Standard 1/4-inch phone-type jacks are used for both input and outputs, making the CH-1 compatible with virtually any instrument-level source. You can power it with a 9V alkaline battery or any BOSS PSA-series AC adaptor, and the pedal draws 55 mA at 9V DC — an efficient choice for most isolated pedalboard power supplies.

• Outputs: 2 × 6.3 mm TS jacks (A mono / B stereo) — split wet and dry signals between two amps for a broad stereo chorus.
• Nominal I/O Level: -20 dBu — matches typical passive guitar pickups and line-level keyboards.
• Input Impedance: 1 MΩ — ensures pickup tone is preserved without loading the source.
• The output impedance of 1 kΩ means the pedal can drive long cables and multiple downstream pedals reliably.

Build, Footprint, and Stage Reliability

Measuring 73 × 129 × 59 mm and weighing 420 g, this pedal fits easily into any standard pedalboard arrangement and can handle the demands of regular gigging. Metal chassis construction, a rubberised stomp area, and a stable base plate prevent slippage on stage, and you get the security of the BOSS five-year warranty programme.

• Dimensions: 73 × 129 × 59 mm — drop this compact unit into any pedalboard setup.
• Weight: 420 g — light enough for travel, heavy enough to stay put underfoot.
• Flexible powering comes from a 9V battery or PSA-series adaptor with 55 mA current draw, making it suitable for both studio and stage use.