

there are at least 3 different versions of this circuit. The first DM-2 version was using the MN3005 BBD and the MN3101 Clock Driver IC (PCB marking: ET5214-510).
Later they changed the clock driver to MN3102 and the BBD to the low current version of the same circuit, the MN3205 (PCB markings: ET5214-510A and ET5214-510B). The MN3205 is a little noisier, but it generates less distortion (only 0.8% compared to 1% for the MN3005).
ICs, transistors and diodes used in the Boss CS-2 pedal:
ICs, transistors and diodes used in the TR-2 Tremolo pedal:
The Boss OC-2 Octave pedal produces additional tones, one and two octaves below the original note. The pedal has a direct level control knob for exact tonal shaping and separate controls for octave 1 (OCT1) and octave 2 (OCT 2).
The MT-2 Metal Zone™ is one the most popular guitar pedals, providing over-the-top, insane distortion tones with huge mids and lows and an ultra-saturated sound. It has a unique dual-gain circuitry, providing long sustain and heavy mids and lows like a stack of overdriven amplifiers. The 3-band equalizer with semi-parametric mid control offers a wide range of extreme distortion textures.
ICs, transistors and diodes used in the SD-1 Super OverDrive:
The Boss SD-1 Super OverDrive is a pedal with a simple design, using only one dual operational amplifier (uPC4558C) and 6 transistors, with an asymmetric overdrive circuitry for a classic, natural tube amp growl. It generates the warm distortion of an overdriven tube amplifier while maintaining the subtle nuances of a guitar player's picking technique.
The schematic is nearly identical to the classic OD-1 OverDrive, the only major difference is the tone control circuit. The design is simple and easy to follow: the guitar signal is buffered with Q5 and enters the first half of the uPC4558C dual operational amplifier. There are 3 silicon diodes in the negative feedback path of the op-amp. Two diodes are in one direction and only one in the other. This arrangement produces asymmetrical soft clipping -- one side of the waveform is clipped more severely than the other. The tone corrector and level control circuits are next. The signal finally exits the circuit after the output buffer made with Q6. The bypass circuit uses a classic arrangement with 2 JFETs (Q1 and Q2) serving as solid-state switches and a symmetrical bistable multivibrator made with Q3 and Q4.
The OD-2 was manufactured as a replacement for the OD-1 in the mid 1980s and uses only discrete components. It has 3 potentiometers for level, drive, tone control and a switch for selecting two modes of operation. When set to the OFF position the sound is similar to the OD-1 but in the turbo mode it generates more gain and distortion.