- Every module must cost less than £10, including all components, connectors and the front panel, but not the knobs.
- Every module will be the same size, around 6"x3", more about that later.
- No specialist parts, indeed many can be recycled from old projects.
- All connections will be via 4mm banana plugs
- A 10 Unit rack will cost less than £20 including power supply.
- No direct connection to the mains
- All external connections through 1/4" jacks.
- The VCOs will not be stable, or linear enough to play tunes, this is an effects and treatment device only. However this doesn't mean it isn't musical a later extension will allow you to use a cheap home keyboard as a sound source.
- Power supply will be external, +/- 9Volts
- All modules will be built on veroboard, there will not be a pre-made PCB. But then that's how the Synthi-100 was made.
- There will be printable front panels which you will have to cut out and stick yourself, so it will be as good looking as you want to make it.
- You will need to be able to solder, cut 3mm plastic sheet or thin plywood accurately and have a bit of patience.
Basic designThe basic design will be for a frame that can take up to 10 of the modules listed below. Plans for this, the power supply and output module will be listed here before the book is published.
I am planning to publish designs for all of the modules listed below, but so I don't delay publication they won't all make the first edition, however once you have purchased a copy the updates will be free.
Complete or partially complete
- Power supply module (mandatory)
- Output module (mandatory)
- VCO, exponential, almost 1V/Oct but unstable, 1 V/C input with attenuator, one without, ramp only out. (Might include sync if I can do it for under £10)
- LFO, manual frequency, square, ramp or saw output. 3 ranges.
- Joystick, provides +/- 9V on each axis. Might include trigger button if I can fit it on the panel under budget, this one is going to be hard to do.
- Ramp to square + PWM module
- Voltage controlled filter (Moog ladder) approx 1V/Oct
- Voltage Controlled Amplifier. No idea yet
- AR generator, with repeat so can be used as second LFO.
Planned but work not started
- 7 stage sub octave module
- Noise generator
- Input amplifier
- Envelope follower
- Ring modulator
- Sample and hold
- 8 stage trigger sequencer
- Tap pad and trigger
- Speaker/headphone amp
- MIDI interface for control voltages. This one is quite complex, and will probably need a PCB to be made so it can't be done for under £10.
I will publish photographs and the initial designs here early 2013.