Semiconductors and Misc components

Diodes d1-d16

BAT42 or other suitable shottky diode (0.025" hole size)

D7-D16 are optional for using extra gate inputs or outputs

with digital controls 1-5

U1

Atmega 328p

You can buy one per-programmed with arduino boot loader and load the sketch with a normal FTDI cable (both avaliable from adafruit, sparkfun etc)

buy an arduino boot loader one and program it on an arduino if you already have one.

Some will be available with pre programmed sketches ready to go in 2014

U2

4052 analog multiplexer

Newer cmos switches are much better then the original CD series, 74HC etc.

U3

TL074 DIP

Regulator

7805 or digital box such as TRACO TSR1-2450 (less heat)

inductors

L1,L2

Ferrite bead choke

L3,L4

optional

for noise reduction and precision. (cut trace)

crystals

crystal

16mhz

“arduino crystal" from sparkfun etc

Connectors

FTDI header

6 pin male header

connectors

you can hard-wire , use pins, or use 0.1" IDC headers

Optional IDC headers

3x2pin 1x3pin 1x4pin 2x8pin

power

4 pin molex for MOTM or 10 pin for euro.

IC Sockets

4x14 pin

or 2x 14 pin and 1x28 pin

With most IC sockets, you can use 2x14pin sockets for the 28 pin

Resistors

r1

499k 0.1%

R2

3.9k 0.1%

R3, 15

10k

R4

220R

LED diode. Calculate for LED @ 5v, use higher if too bright

R5

16k

R7

82k

R8, 18

120k

R6, 9, 12, 13

220k

R10

2k

R11

330R

Output resistor, use what is most common for your synth

R17

20k

R14

10k

Decrease this value to increase amplification of CV in. increase to 14.7k for unity (-10v to 10V = 0 to 5v)

R19,20,21,

100R

R 23,24,25,26,27

220R

Depends on program, but with 220r you can use those 5 pins for switches or LEDs, (or gate/logic inputs/outputs with optional protection diodes) if you will just be using these pins with front panel switches, you can jumper those resistors.

,

Capacitors

bp

100N ceramic

c4

100n ceramic

C1. C2, C3

10u elect

c5, c6,

22p ceramic

c7

2.2n

You can use ceramic, better quality like C0G will be more accurate,

or film capacitors which are more accurate and may “sound better”

c8

4.7n

c9

1n

c10

47n

c12

10n

c11

22n