Kobol Clone

Project

Updated: 02/2023

you need 2x SSM2050 or use 2055/2056 with a mod.

This documentation is only for myself, to have some notes about changes and mods

This PCB which I used isn't available anymore !!

Theres no support available and much knowledge needed.

Sync sounds:

Backup from Crazy.P incl. SSM.-SSI adapter pinout

ISSUES

Nr.	Description	Priority		Solution
1	Switches - use other pcbs footprint size and/or change panel to toggle switch	1
2	BOM : LOG for Volume LFO and VP out gain	3		fixed
3	missing mounting holes for pcbs	2		open
4	LED driver needed for gate led	2		fixed
5	leds polarity on pcb	3		fixed ?
6	LFO speed inverted pot, left is fast on the prototype	1	Or use reveresed Poti	fixed
7	panel holes too big for potis	1		open
8	powersupply design not allowed -	2		open - use a own PSU - Yamaha PA30 and resctifier, capactitors
9	markers for voltage test points missing	3		open
10	more clearly infos about matched trannys and resistors	3
11	envelope change too CEM3310 or digital	1		open
12	capacitors are too close next to the power supply section on mainboard	1		fixed
13	use bigger traces	1		open
14	Gate signal bleed in LFO	1	Blocker	fixed
15	V/oct unstable - waveforms wobbling -	1	Blocker	fixed
16	Lfo led not working	3		fixed
17	Holes in vcf board and VCO board to mount on metal spacers - for better mounting	2		open
18	Case doesn't fit with the panel	1		workaround possible
19	ua726	1		use normal matched pair trannys
20	ssm2040	1		use the new SSI 2040 !!
21
22	knobs ask Patrick_H

changes:

in crazy.p clone R135 ---> 68pF

in Crazy.p clone R207 ---> 22nF

please note the 3Pin Connectors are wrong in the Wiring guide !!

Ground is the middle pin on the 3Pole connectors.

for all jacks:

S is to be connected on TIP Pin (hot)

SW is the Tip Switch Pin (for grounding when no plug is in the jack inserted)

Switches

needed: 1x 2 rows with 3 pins (ON/OFF) power (DPST)

		mouser	RS
power		SSSU022800
4x normal			SSSU015100

or:

mouser

ordered

power

MHS222K not avail.

06-MHS22204

4x normal

MHS122K

apem

home stock


Pots			50€ thonk T18 shaft or round shaft- you need 2 center pots and 1-2 Log 100KB 2xx 100kA 100KB center detent for tune and vco2 beat optional for Freq. its up to you. look at crazy patroches pic and in the BOM
jacks			45€
resistors			30
capacitors	2,2MF	reichelt	5euro
ICs: 3080, lm324, lmxxx			estimated 100€
trannys, Power reg.			5
diodes			2
switches mouser			10-20
cable and headers			20
SSM2050	2x		480€ or ask me for a replacement VCA/ADSR PCB to use CEM3310/AS3310
heatsinks	2x		5
external Yamaha PA30			50€
SSM2040			Ebay 50 or use new SSI2140 with adapter 10€
case			Buchla boat from SAMODULAR - cut the frame to make it fit 100€
ic sockets			10-15€
Yamaha PA-20 powersupply			40€
knobs tme			GWB19BK
LEDS	3x		red

VCO: linearity = High Freq. compensation. = there's a 1Mega Resistor which is connect to the Trimmer - adjust the Trimmer as close to 0V (which is a OFFSET and affect the V/Oct calibration)