2. Making your own overtone flute
3. Fitting EMT-140 mono tube plate reverb with XLR connectors
The following little and easy to build thingie will enable you to use any external light source as a modulator for any synthesizer or device with a control pedal option.
The pedal itself is no more than a simple potentiometer, which you control with your foot. The pedal is connected to a synth with a 6.3" stereo jack. The synth sends a certain voltage along one of the three wires, something like 10-15 volts, which is then attenuated with the potentiometer, and the resulting voltage is sent back to the synth along another wire. The voltage that the synth receives determines the amount of the control. The third wire is for fixing the voltages to the same reference, the ground.
For example, if the synth receives back the same voltage it transmits there will be no effect at all, while receiving zero voltage the effect will be at it's maximum. I don't know if this really is the way it works, but I think I have got it mostly right.
What you need now are: a cable with 6.3" stereo connectors, 4 wires with alligator clips in the both ends, a potentiometer and a light dependent resistor. The control pedal which I have, has a 47 kilo ohm potentiometer. I have used a potentiometer having the same maximum resistance. The parts should cost no more than a couple of whatever currency units you may have in use.
Plug the other end of the cable to the place where you usually plug the control pedal. In the fancy image below, the thing on the left represents the free 6.3" connector at the end of the cable (the other end being plugged to the synth). The uppermost area is the ground, and the next two areas are for the sent and received voltages. The potentiometer on the right is seen from below. The Omega sign represents the light dependent resistor. Make the connections as suggested in the image.
The potentiometer is used for setting the approximate voltage range where the light dependent resistor works. The resistor itself can't handle the voltages present. Without the potentiometer and it's extra resistance, the resistor doesn't make much effect at all.
The way things are connected in the image, is to make the control effect increase when turning the pot clockwise, as is the usual case. Changing the places of the ground wire and the wire coming from the resistor in the potentiometer makes the effect increase when turning the pot anti-clockwise. The green wire can also be connected to the middle section of the jack and the resistor to the tip. There may be small differencies how the synths route the voltages. More resistors can be added and connected in series or parallel with the first resistor. If you leave the resistor out completely and connect it's wires directly, you have a potentiometer in your synthesizer or device.
I have built this on a perforated board, having a female jack for the connection with the synths, the potentiometer, and two female rca connectors for connecting the resistor(s).
I have experimented with this by attaching a couple of resistors to my lava lamp and using it's naturally random properties. The Sun could be used as a modulation source, or flashing lights to create cyclical and sharp effects. The possibilities are endless. There exists resistors dependent on temperature, which could be used to modulate things. The potentiometer itself could be attached to a plate, which would turn with the wind.
I have tried this with Yamaha DX-7II and Ensoniq ESQ-1. With a friend we managed to record the control input of his Nord Lead Modular as MIDI data, and to use it to create strange and interesting light dependent rhythms and beats. With MIDI, the signal can be routed to control anything.
If you destroy your synth or other device with this thingie, it's obviously your own fault and practically impossible anyway, so you may congratulate yourself should it happen.
These are instructions for making your own overtone flute. All you need are a knife, a saw, a ruler, a plastic PVC plumber/electric/air pipe (diameter 16-22mm), a piece of wood and 15 minutes. These instructions are based on an article by Matti Nuortio (Sivarijulkaisu 12/00). I got interested in the overtone flute while doing research for the Dragonbane project.
1. Cut the pipe to a length of about 70cm. The lenght can be almost anything you wish, the longer the lower the fundamental frequency etc.
2. Prepare the soundhole. In the picture this is the hole below the blowhole. It should be 12mm wide and 7mm deep. The edge of the soundhole should be made sharp as shown in the picture. The sharp edge cuts through the air and makes the sound loud and clear.
3. Prepare the mouthpiece. I've used a piece of willow trunk, which fitted nicely into the pipe and was round enough without much processing. The mouthpiece should be tight enough so that you'd have to force it in and out. The drier wood the better, as damp wood will shrink a bit when it dries. The air shaft from the blowhole to the soundhole should be flat and smooth. Beware of making it too deep first (the picture is not in scale). Pursed lips should be enough to close the blowhole, so better not to make it too wide.
4. Insert the mouthpiece to the pipe and your flute should now be ready. Experiment with the position of the mouthpiece to find the cleanest and loudest sound. If all you hear is blowing noise, your mouthpiece probably needs to be adjusted or prepared again.
Closing the other end of the flute with your hand halves the fundamental frequency and makes the sound even louder and clearer. You can also play melodies and make the pitch bend by opening the end of the flute gradually with your hand. Using these same instructions it's possible to prepare an overtone flute out of a copper pipe and a metal mouthpiece too, except you'd probably wreck your knife.
Fitting EMT-140 mono tube plate reverb with XLR connectors
The diagram marks the original audio connector. There are two of these connectors, of which the lower one (was labeled as '1' in my case) has both the input and output of the amplifier routed to it's pins. The upper connector is not needed.
1. antiphase out 5. phase out 2. ground (chassis), 0-volts 3. antiphase in 4. phase in.
In the XLR connector the norm is 1. ground 2. phase 3. antiphase.
1. Remove the original connectors and deattach the wires (make notes which kind of wire goes to which pin !)
2. Attach the wires to two XLR panel mount connectors (female for input, male for output).
3. Mount the XLR connectors to the holes left by the original connectors (one screw seems to be enough)
The ground and 0-volt wires (in my case they were coloured yellow-green and blue) should be kept as connected together (to XLR pins number 1). The open ends of the wires left unattached (mainly the wires of the obsolete upper connector) should be cut or taped up to prevent any harm when stucked back inside.