Revised Envelope Filter (2010)
Envelope Filter & Fixed Wah PCBEnvelope Filter SchematicParts ListResistors
R1 - 1M
R2 - 10K
R3 - 1M
R4 - 22K
R5 - 150K
R6 - 1K
R7 - 1K
R8 - 10K
R9 - 22K
R10 - 22K
R11 - 22K
R12 - 1K
R13 - 1K
R14 - 10K
R15 - 10K
R16 - 22K
R17 - 22K
R18 - 100K
R19 - 1K
R20 - 1M
R21 - 150K
R22 - 22K
R23 - 10K
R24 - 22K
R25 - 22K
R26 - 4.7K (LED)
VR1 - B100K (Range)
VR2 - C250K (Sensitivity)
VR3 - B100K (Attack)
VR4 - A100K (Manual)
Semiconductors
Q1 - 2N5088 (2N3904, 2N2222)
IC1 - RC4558 (or other dual op-amp)
IC2 - JRC13600 (or other dual transconductance op-amp)
D1 & D2 - 1N914
D3 - 1N4001
D4 - LED
Capacitors
C1 - .047uf
C2 - 4.7uf Electrolytic
C3 - .01uf
C4 - .01uf
C5 - .01uf
C6 - .1uf
C7 - .1uf
C8 - 4.7uf Electrolytic
C9 - 4.7uf Elctrolytic
C10 - .001uf
C11 - 100uf Electrolytic
C12 - 4.7uf Electrolytic