R1
220K
R2
68K
R3
8K2
R4
1M*
R5
2K2 (CLR)
C1
1n
C2
3n3
C3
68n
C4
47p
C5
10n
C6
47u elec
C7
47u elec
D1
1N4001
Q1
2N2222**
BOOST
10KB
HEAT
1KB
RANGE
500KA
Sch BOM
*R4 is an optional anti-pop resistor.
** See notes overleaf regarding pinout/orientation before placing.