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Projecttitel: Yusynth Arp4072 Filter


Startdate: 2010

Duedate: 2010

update Q4/2014

Manufacture link:

It was my first DIY Build - so sorry for the building quality (wink)

added a second DIY project 2014 with better quality..

Attention: for bridechamber pcb (SA798) version,  the output is wrong.    correct:GND to TIP,  Signal to GND

BOM parts..

4  x 47k Linear Poti für others (freq, Resonance etc)      banzai Alpha 16mm FS 50k lin

2 x 47k Log Poti für Input Level  banzai Alpha 16mm FS 50k log

6  x knobs

6 x female 6,3mm mono (switchcraft 112AX or equal.)

pinheaders/connectors or hard wire linking to frontpanel


Building details

Japanese dual transistors version
Q1 to Q6
or Q1 to Q12
either 2N3906 or BC557 matched by pairs (caution the pin out is different, see layouts above)
or 12
R1,R210 ohms 5% - or 2x ferrite (better)2
R8,R10*,R11*,R15*,R16*,R20*,R21*,R25*,R26*220 ohms * matched to 1%
5% otherwise
R7,R9*,R14*,R19*,R24*,R42,R461k * matched to 1%
5% otherwise
10k * matched to 1%
5% otherwise
R4415k 5%1
R40,R4127k 5%2
R4533k 5%1
R3,R4,R5,R6,R30,R31,R32,R34,R39100k 5%9
C3,C4,C5,C6470p matched to 1% ( i use Glimmercaps they have 2%)4
C1,C2,C9,C1022µF 35V4
T22k2 10 turns trimmer  3296w series for bridechamber pcb, otherwise Y1
T147k 10 turns trimmer  3296w series for bridechamber pcb, otherwise Y
P1,P247k log potentiometer2
P13,P4,P5,P6 (see latest entry)47k lin potentiomter4
Jk1,Jk2,Jk3,Jk4,Jk5,Jk6female jack sockets6
DUAL GANG POT for Resonance (bleed thru fix)dual 47K linear1


2k2 trimmer


 Reichelt Parts ohne Frontplatten poti etc:


Bleed through FIX (high esonance and tracking is better too)

this means unsolder the left leg of R43, solder a wire this leg and connect this wire to the wiper lug of the second potentiometer of the dual-gang pot.




Schematic from Yusynth