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OmniMuff v1.0
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4
Build options
This PCB can be used to mimic an extreme wide range of vintage to modern Big Muffs. In total 29
versions of the original Version 1, 2, 3, 6, 7, 8 and 9 as well as some famous clones (EQD, Colorsound
et
c.) can be built with just this single board. OMG, the stress of choosing which one to build….
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more!!
In the components section you will find the components needed for the different configurations.
When it says “jump”, there is no component to be place
but instead you’ll need to connect both pad
of the component with a jumper wire (eg a spare piece of lead wire you get when cutting a resistor
to size). When it says “jump 1
-
2”, then you’ll need to connect pad 1 to pad 2 of the component with
a jumper wir
e. With “
jump 5-6
” you’ll need to connect pad
5 to pad 6 of the component with a
jumper wire, etc.
A dash (“
-
“) means there is no component
nor jumper to be placed at that spot for
that type of Big Muff. Just a few examples for switch 1 and 2:
The PCB was designed to use PCB mounted potentiometers (
P1
-
P3
) on the back of the PCB, but you
are free to use more traditional solder lug chassis potentiometers. Rectangular pad on the PCB marks
pin3 and that corresponds with this numbering of the solder lugs:
VR1
is arranged as onboard trimpot on the PCB. This is done because for most people it is set and
forget. However, you could choose to make it external by wiring a chassis pot. For this I added the
pinout next to the trimpot pads so you know what pad to connect to which pin on the pot.
Because the different Big Muff versions used a lot of different transistors, I marked the pinout on the
PCB (EBC/CBE). Before you place a transistor, make sure the pins correspond to the letters on the
PCB. I cannot stress this enough! Also note that 72#2 version 1 Triangle is a
PNP
effect that means
that it needs
-9V
(positive ground). You can do this by simply reversing the black and red wire of the
DC, but that also means you can not use it with a daisy chained power supply with other +9V effects
or things will go really bad and I predict smoke will come out somewhere! I suggest you leave out the
DC Jack in
PNP
versions of the Big Muff and only use a reverse wired battery. This way it can be used
in a chain of +9V effects.
SW1
is added so you can switch the Colorsound Tonebender stage 1 diodes and caps in and out of
the circuit instead of just leaving out the components. That way it is more versatile. This option is not
mentioned in the component section as it is not part of the original!