22/7 on OSH Park

Built and test this second version of the 22/7 by RunOffGroove.com. Sounds good. This is a great alternative for Big Muff fans. The OSHPark project is public and verified.

22/7 is a Big Muff built around CMOS inverters in place of the transistors used in the traditional BMP circuit. The CMOS inverters have a tube like sound when over driven.

You can order boards for this project at PCBWay.com. I have two versions of the board. One uses the 4049 and the other uses the 4069. Otherwise the rest of the parts are the same.

Order PCB here: 22/7 PCBs on OSHPARK

Parts List

Capacitors
C1        100µ
C2                   33n
C3            100n
C4             220p
C5               150p
C6                150p
C7             100n
C8              100n
C9                  3n3
C10                6n8
C11                 10n
C12                10n
C13               100n
C14               150p
C15     100n
Diodes
D1-4    1N914
D5              1N5817
D6           LED
IC
IC1       CD4049UBE
Resistors
R1      100K
R2                 470
R3       1M
R4       1K
R5      33K
R6       1M
R7        33K
R8       1M
R9        39K
R10         27K
R11                  1M
R12      1M
R13               330K
R14           100K
R15         RLED
Switch
RANGEON OFF ON 
Pots
SUSTAIN A100K 16MM 
TONE    B100K 16MM
VOLUME   A100K 16MM
Parts

Wiring

If you don’t want to build your own this one is for sale on Reverb.


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Comments

4 responses to “22/7 on OSH Park”

  1. Claudio Avatar
    Claudio

    What’s supposed to go to R15, what’s that resistor on the 3PDT Switch?

    1. admin Avatar
      admin

      R15 is the current limiting resistor for the LED. Use anything from 470r to 10k depending on the LED. 1K to 4k7 is a safe choice.

      That resistor on the switch in the images is a 0r (0 ohm) resistor. I used as the wire to connect the two outer pins. Take a look at the wiring diagram for the switch and compare.

      1. Claudio Avatar
        Claudio

        Thanks for the reply. I actually figured out R15 as soon as I posted that when I noticed the trace was connected to the LED. I usually use a 2.2k resistor.

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