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Blue Fool Octave-down fuzz fun from this MXR Blue Box clone PedalParts.co.uk...
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Schematic Green shaded area is a LPB boost circuit to bring the signal level up to above unity. This isn’t in the 330R original circuit. 150K The switch selects between 100K 2-octaves down (original) and 1-octave down (mod). 470K 390R RLED 2K2 (CLR) 330p...
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SWITCH This is optional, but why wouldn’t you include it? If you want to take it out, connect the switch pads in one of these combinations: 2-OCTAVE DOWN (ORIGINAL) - connect pads 1-OCTAVE DOWN - connect pads Wiring shown overleaf will disconnect the battery when you remove the jack plug from the input, and also when a DC plug is inserted.
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Test the board! A A T Once you’ve finished the circuit it makes sense to test is before starting on the switch and LED wiring. It’ll cut down troubleshooting time in the long run. If the circuit works at this stage, but it doesn’t once you wire up the switch - guess what? You’ve probably made a mistake with the switch.
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Wire it up The Board GND connections don’t all have to directly attach to the board. You can run a couple of wires from the DC connector, one to the board, another to the IN jack, then daisy chain that over to the OUT jack. It doesn’t matter how they all connect, as long as they do.
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