Schematic
BOM
R1
100R
(68K*)
R2
22K
R3
12K
R4
100K
R5
1M
R6
2K2 (CLR)
C1
10u tantalum
C2
1u5 tantalum
C3
100u electrolytic
Q1
JFET (2N5457, J201)
POT
50KB (
50KC**)
*Original value - smaller value is less intrusive.
** Reverse log gives better control if you can get it