Lunetta Guitar VCO Test

YouTube Published on Jul 4, 2012 by NakagawaGakki

Here is a short test displaying the potential of the dual CD 4046 VCOs Ive just made. Still on the breadboard ATM but soon to be fitted to the Modular Lunetta Synth Guitar!!!
Modules are all sticking to a 50mm x 50mm format. Horizontal Frame rails carry ground.

A run down on whats happening in this vid.
2x CD 40106 LFOs sending clock and data to an 8bit Cipher Gate Sequencer:
Cipher Info here: http://www.sdiy.org/pinky/data/data.html
Cipher sending patched sequenced gates to 8 motor drivers of my own design.
These in turn are each sent to an updated Gate to trigger module alongside each motor, this works really efficiently and the strings resonate well.
Gate to Trigger info: http://www.cgs.synth.net/modules/cgs24_gatetotrigger.html
I have the capacitors removable to compensate the differing strength/length of trigger needed for various string thicknesses.
Likewise the Cipher is also sending its goodness to 2x 4bit Digital to Analog Converters (DAC).
DAC info: http://www.ikalogic.com/8-bit-digital-to-analog-converter-dac/
The resulting analog control voltages are run through a potted slew/glide circuit, based on a Nonlinearcircuits design.
http://www.sdiy.org/pinky/data/bin5schem.pdf Look at the two op amps in the bottom right corner around P5; the 1M pot.
These Control Voltages (CV) can be sent to analog synthesizers but in this video they are sent to 4x CD 4046 Voltage Controlled Oscillator chips.
1 CV is sent to 2 VCOs doubled up in a unique fashion courtesy of Slacker on this forum: http://www.electro-music.com/forum/viewtopic.php?t=33607&postorder=asc
"Basically you connect pin 11 of the first 4046 to the clockwise lug of a 100k - 1M pot and connect pin 11 of the second 4046 to the anticlockwise lug. Then connect the wiper to ground through a 10k resistor. If you stick the pot in the middle and feed both VCOs the same CV, then within the tolerances of all the parts they play the same tune. If you move the pot towards either extreme the base frequency of one of the VCOs goes up and the other goes down so you get harmonies..."

I have the VCOs on switchable capacitors to make them hi/lo range.
Am currently trying to make them switchable automatically by using gates into a CD 4016.
http://www.doctronics.co.uk/4016.htm

Sorry sound quality not so good, camera mic used to catch the acoustic string plucking and distant sound of slewed VCOs in one hit.

There are lots of Lunetta circuits to be found on the vibrant and friendly forums of Electro-Music: http://www.electro-music.com/forum/index.php?f=160&sid=cc1a6c915ec8d6a536b072ee72a8ae76"