Micronoise pro

Concept

This circuit can create more complex noises than the original one since it uses all 4 NAND Gates of the chip. Depending on the used values of the parts it can produce metalic spectra or polyrhythmic beats. A optocoupler is used to control one of the NAND gates with a control voltage.

Parts

• 1* 4093 IC

resistors

• R3- R6 are just bridges you can also use wires, for one of them no resistors is used but a connection to the optocoupler is made(CV 1 & CV2)
• R1 470
• R2 8.2k
• R3 - R6 10
• R7 1k

capacitors (use different values for other frequency ranges)

• C_A 100n
• C_B 1u
• C_C 4.7u
• C_A 47n

• 4 Potentiometers 500 or 100 kOhm (Alps PCB mounted) unsed for A-D tune
• 2 Potentiometers 10 kOhm (Alps PCB mounted) used for power and CV amount
• 1* Transistor (e.g. BC548)
• 3* switches (MULTICOMP SWITCH, PCB SPDT VERT on-on)
• 3* Jack connector (lumberg 1502 03 PCB mounted)
• 1* LED(for optocoupler)
• 1* LDR(for optocoupler)
• 1* piece of heat shrink tube(for optocoupler)
• 1* Battery Clip & Battery

Schematics

All 4 NAND Gates are connected in series from C to B to A to D. The values of the according capasitors are decreasing resulting in a higher frequency from the first to the last gate. The A/B switch connects the A or B NAND gate to the A/B Out-Jack. The B-IN switch connects supply voltage or the C NAND gate to the B NAND gate. The CV-ON switch turns the control voltage on/off. a transistor is used as a LED driver for the optocoupler.

Board

Mask (bottom): File:Micronoise pro pcb.pdf

Parts (top): File:Micronoise pro parts.pdf

EAGLE Files: File:Micronoise pro eagle.zip

Modifications

On the board you find direct out connections for the signal all NAND gate oscillators (OUT A - D). These can be used for nice modifications. Connect an LED with appropriate resistor between these outputs and ground for a visual feedback. There are several ground points on the board (GND 1-4) already. One of the outputs can also be connected to the normalised CV In connection of the optocoppler. Like this you the CV modulation will work without conection the CV In.

Built Devices

Micronoise pro in a case with additional 4 switches for routing signals of the NAND gates to the control voltage in. There is also a DIP socket for chosing the NAND gate that is controlled by the control voltage.

For this micronoise pro a laser cuted plexi front plate was used. The pads of the NAND gates output were connected to 4 LED with different colors to get a visual feedback of the sound.