This is my take on Tim Escobedo’s Ugly Face. I replaced the LM386 with a dual op-amp and and added a mix control.
The LM386 is a great chip but its gain is limited to 200. A single op-amp can easily generate a gain of 200 and more! This way I can replace the 386 with another 8 pin DIP and use the extra op-amp to create a summing mixer.
Here is a schematic:
Parts List
C1 | 220n |
C2 | 1n |
C3 | 10n |
C4 | 100n |
C5 | 100n |
C6 | 470n |
C7 | 100n |
C8 | 220p |
C10 | 100n |
C11 | 100µ |
C12 | 47µ |
C13 | 100µ |
C14 | 2µ2 |
C15 | 10µ |
D1 | LED |
D2 | 1n5817 |
ENVELOPE | B1k |
FREQ | C100k |
THRESH | B10k |
VOL | A100k |
MIX | B10k |
IC1 | TL072 |
VACT_1 | LED/LDR |
IC2 | 7555 |
R1 | 1M |
R2 | 470 |
R3 | 100K |
R4 | 56K |
R5 | 1K |
R6 | 47k |
R7 | 2k |
R8 | 10K |
R9 | 10K |
R10 | 1M |
R11 | 200K |
R12 | 1K |
R13 | 15K |
R14 | 15K |
R15 | 15K |
R16 | 15K |
R18 | 15k |
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