Buddha Machine Therimin Circuit Bend



No guarantees this will work on your machine, but hopefully it will. If you’re here, you may or may not know about the buddha machine. In brief, it is a small audio loop player created by the ambient electronic band FM3. IIt is LO-FI, and designed that way. MINIMAL. and I tried to follow the tradition. I was lucky back in 1999 – 2001 to actually live with Christiaan back in Beijing, one of the most amazing musicians (and writers) I’ve ever met. I would come home sometimes and he would be up editing music on his little Toshiba laptop for 36 hours working on songs with Zhang Jian — back in the days where great music was made in living rooms and not in some shmancy studio. Little did I know they would go on to create such an amazing device that is beloved by electronics hobbyists AND DJ’s alike all around the world. I am no DJ, but I love to tinker with stuff. He left me with some Mark I’s and I decided to play around with one. this is my hack.
I discovered this after poking around looking for voltage drops along the various pathways. I was so excited, emailed Christiaan and found out someone else had actually made an elaborate variable resistor hack to do manual controlled pitch bending – located HERE. This is awesome I thought!! But I wanted to make it like a Therimin. so, this is what I set out to do on christmas day, 2010.
1 X MARK 1 BUDDHA MACHINE — i have not tested this on any other machines, but it probably works.
1 X BK4G J201 “JFET” transistor, costs about 50 cents. I do not know any substitutes, this is a general audio amp NPN transistor. However, I’ve tried others and they don’t work as well… So, if you can find this, go for it. Radio Shack or Fry’s probably sells something very similar, ask for a JFET and just pick a couple up see if they work.
2 X thin guage wire, used for extension, maybe old jumpers about two or three inches long. these will be the “source” and “drain” wires

1 X thin guage wire, this is gonna be about 6 inches long, this will be the antenna.

1 X tiny ass piece of adhesive tape, anything will do. about the size of a fingernail is enough.
soldering iron with a good tip and a little bit of solder
hot glue gun, or just some super glue, some sort of adhesive to tack down the FET to the board
uh, that’s it…

THIS HACK IS BASED ON BILL BEATY’S RIDICULOUSLY SIMPLE AND SENSITIVE ELECTROMETER: I just applied it to the buddha machine as a pitch bending aid.


1) open up the machine, do not cut any wires at all during this whole processbuddha-resistor
2) take out the board and flip it over where you can see the components right side up.
3) near the loop selector switch locate the resistor that is sticking out, it’s pretty obvious. This is a 2.7 million ohm resistor by the way, and, it is the pitch bending portion of the device we want to mess with. If you simply put your finger on both leads of this resistor, the pitch will change slightly — but we want MORE!! The resistor has a left side and a right side, we will call A and B. it doesn’t matter which is which, just know that each resistor leg is separate in this hack — meaning, don’t do a shitty soldering job and goop up both legs connected… they must remain separate.
4) bend the resistor up a little bit and DONT break it, just bend it so you can attach the wires more easily.
5) get your FET transistor (fet) and take a look at it. place the flat side DOWN, the curved side should be facing you.
The pinout goes like this:
left leg = antenna
middle leg = resistor side A
right leg = resistor side B.
6) Take the left antenna leg of the FET and bend it upwards, like a hand waving. get it out of the way of the other two.
7) take your 2 pieces of 2 inch extension wire and solder one to each middle and right leg of the FET.
8) take your long antenna wire and solder it to the antenna leg of the FET.
9) At this point, you want to cut a small notch in the BACK SHELL — THE BACK SHELL!!! of the machine located across from the decimal of the 4.5 V marking of the DC power input. this is where the antenna will go through. Don’t glue anything to the shell, remember, you still have to take this thing apart sometimes…
10) very carefully solder the extension wires to the sides of the resistor, this is CRITICAL… if this is done wrong it ain’t gonna work… and you’ll be emailing me and I will tell you to redo it. TEST it first, bend the wires around the resistor and test it first. don’t use much solder at all, just a tiny bit will go a long way. I can’t give you any more advice than this, it’s purely up to your ability to solder something that tiny.
11) once the extension wires are on, I would suggest taking a small bit of adhesive tape and place just a tiny bit on the board itself blank area near the DC input port. This is where the the FET will rest and we don’t want to pass any current accidentally to the board. this is very close to the FLASH circuit, so watch out!!!
12) You should’ve tested this by now and I will assume it’s working, now you need to hot glue your FET to the board (flat side down), one drop will do.
13) drop some hot glue on the antenna and make it stick to the board so it doesn’t damage the FET arm while moving.

14) put the shell back on and make sure to place the antenna in the notch you cut out.


15) THAT’S IT. If the device shorts out while you are doing this, just restart it, I shorted it out maybe 50 times, it’s pretty tough.buddha-FETboard
— check your solder points first,
— test this before soldering everything together…
— don’t touch the antenna unless you want to RESET the feature… read “physics of the device” below

First, read about JFET. Then, you need to understand that static electric fields are around us constantly, and they are quite high voltage, very low current. Just walking barefoot on carpet will generate tons charge, which will trigger this device easily, even from several feet away.So what’s going on??? Well, the FET is a transistor, it is like a very sensitive switch. in this application we have extended it’s “gate” with a wire, allowing it to “collect” charge in the air. Once it collects enough, the tiny microscopic amount of doped semiconducting material inside it is either attracted or repelled depending on the state of charge in the air. This turns the switch on and off very quickly, and a lot of times, not completely, so in this application you get a fading in and fading out effect (i.e. NOT A SQUARE WAVE) — along with a pitch bend effect because we have placed it directly on top of the pitch control resistor. Basically, you are manipulating the existing field around you and on you, and this motion of the field short circuits the resistor.
THIS DEVICE IS WEATHER SENSITIVE. yes… no shit. if it is really dry, that means there is very little moisture to carry the charged particles in the air space around the device. Humidity works best. this should also function as a lightning detector, however I haven’t had a good storm out here to confirm this, but it should.


— sometimes touching the antenna will RESET the device, basically grounding it and destroying the field. this is sometimes useful if you want to get back to the original loop —
HOWEVER, if you leave it alone, it will again detect the existing field and change pitch on its own. so, someone might want to put a switch on this on one of the extension legs to control the reseting. I’ve reset it (touched the antenna) and it will again detect charge within about 30 seconds.
— walk away from the device, then suddenly approach it with your hand like you’re gonna bitch slap it. the sudden approach will drain the field and reset the device. it’s like a kill switch on a mixer.

— this device is sensitive to several feet so, you could walk towards it and physically manipulate it with different body positions.