Build documentation for:
System X Amplifier
Based on the Roland System 100M VCA
Frequency central
Version 2 / April 2013
B100K B100K B100K A100K A100K
CV2 CV1 Initial Input 1 Input 2
Gain
Key to PCB screen print:
n:
This signifies NPN BC547 transistors. Note the correct pinout as shown by the half circles.
p:
This signifies PNP BC557 transistors. Note the correct pinout as shown by the half circles.
f:
This signifies 2N5485 FETs. Note the correct pinout as shown by the half circles.
Gnd:
Ground
Please observe the correct polarity of the 6 electrolytic capacitors. The 4 x 22uF are
configured in sets of 2 back to back (negative to negative).
The PCB shows the correct orientation for BC547/BC557/2N5485. Other transistor types can
be used (eg 2N3904/2N3906/BF245), but please observe the correct pinout.