Buddha MaSsIve

The FM3 Buddha Machines are simple digital ambient audio looper's and a great simple project for Circuit Bending. Although the mk-2/3 and 4 come with a pitch control dial it has a limited range. It is really easy to extended the pitch range to make it go slightly higher to a LOT LOT LOWER by replacing the stock 500k dial with a 1meg pot and overriding the set pitch resistor on the PCB with a lower value (diagrams of this below).

A LDR (Light Dependant Resistor) can also be used to control pitch (bright light = higher pitch and darkness = lower pitch) making the Buddha machine an optical ambient theremin! I have given diagrams and instructions on how to add these controls to all mk1-3 buddha machines below. (sorry no diagrams for MK4 yet buts its the same as mk3 versions.

The LDR i use is a Norps-12 which is a very commonly available LDR (Rapid electronics, RS-components and mouser all stock them). It has a resistance range of 1.5megaohms in darkness to 200ohms in bright light but any LDR with a range of 1k-500k or more is good any less and the pitch control will not be very pronounced aka a bit lame. For the pitch pot i have used a 1m Logarithmic potentiometer wired in reverse (I. E turned fully left the pitch is higher and lowest turned fully right) this gives the best steadily increased / decreased pitch control if you wired the pot the other way the pitch drops very suddenly and its hard to have a medium pitch setting.


I offer this information with the best of intention some models of Buddha machines may vary (early mk-1 for instance) and resistance values may change from unit too unit you may find you need to change the values of some resistors i have given I,E if your buddha machine locks up at high pitch setting make the resistor higher in value I hold no reasonability if you decide to bend / modify your buddha machine but good luck and happy circuit bending feel free to email me with your creations.

MK-1 WiRiNg
Buddha Machine MK-1
1
x
1M log pot
1
x
330 ohm resistor
1
x
spdt switch
1
x
Norps-12 LDR (light resistor)

The first of the buddha machines doesn't have a pitch control as part of the design but the circuit board has easy provision for a good pitch range to be easily implemented.

On the circuit board there should be a empty resistor placement marked R9 (shown as points A/B on the wiring diagram) a pot here can be used to control the pitch but it will not go higher in pitch. The wiring diagram left shows a slightly more complicated set up giving a pitch range slightly higher to a lot lot lower.
mk-2 wiring
Buddha Machine MK-2
1
x
1M log pot
1
x
220k trimmer pot
1
x
spdt switch
1
x
Norps-12 LDR (light resistor)

R2 (270k) on the PCB sets the highest pitch setting by soldering a strip of wire over both ends (shorting R2) and using a 220k trim pot (mine was set to 196k) on the new control pot it is possible to get a higher pitch setting. If the resistance is too low the machine glitches and locks up (stops looping) if your not bothered about making it go slightly higher in pitch simply leave R2 alone and don't use a trim pot t and wire straight to the centre lug of the pot.

mk-3 wireing
Buddha Machine MK-3
1
x
1M log pot
1
x
150k resistor
1
x
spdt switch
1
x
Norps-12 LDR (light resistor)

The third generation B-M uses a higher sample rate and so sounds less distorted and warmer at low pitch settings. The mk-3 uses a 100k pitch pot as standard and so only has a very small pitch range - Definitely worth adding the pitch mod to this little Beauty. Listen to the pitch demo for some bass growl.

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