Boss CS-2 Compression Sustainer pedal

The Boss CS-2 Compression Sustainer effect was sold from December 1981 to June 1986. The pedal compresses high-input level signals while boosting low-input level signals, producing a smooth and long sustain without degrading the quality of the original guitar sound.

Boss CS-2 Compression Sustainer guitar pedal schematic diagram

• Controls: Level, Attack, Sustain
• Connectors: Input, Output, AC Adaptor
• Input Impedance: 1MΩ (FET input)
• Output Load Impedance: over 10kΩ
• Compression Range: 38dB
• Maximum Input Level: -10dBm at 1kHz
• Maximum Output Level: -10dBm
• Equivalent Input Noise: -110dBm (IHF-A)
• Recommended AC Adaptor: ACA Series
• Current Draw: 4mA (DC 9V)
• Dimensions: 70(W) x 55(H) x 125(D)mm
• Weight: 400g

ICs, transistors and diodes used in the Boss CS-2 pedal:

• IC1: BA662A (VCA - Voltage Controlled Amplifier IC)
• Q1, Q2, Q3: 2SK30ATM-Y (N-channel JFET transistors)
• Q4, Q5, Q6: 2SC732TM-GR (NPN silicon transistors)
• Q7-Q11: 2SC1815-BL (NPN silicon transistors)
• D1: S5500G (400V/1A rectifier diode)
• D2-D6: 1S2473 (switching diodes)
• D7: RD5.1EB3 (5.1V Zener diode)
• LED: SLP135B (red LED)

Boss CS-2 Compression Sustainer circuit board - component side