
14
Table 3
–
PSU BOM
10.
Build the 4012 VCF Core. There are six matched transistor pairs (5x 2N3904 and 1x 2N3906).
Additionally, there is one thermally coupled NPN-PNP pair. If possible, try to thermally couple the
1k87 tempco resistor to the NPN-PNP pair. Doing this will mea
n the tempco’s leads will traverse
some other resistors. Consider adding some heat shrink to the tempco’s leads, or just let it
hug
the board.
Do not install the pin headers at the stage.
4012
Resistors
Sockets
220r
1
DIP8 socket
1
470r
6
820r
1
Capacitors
1k
1
10p
1
1k8
1
47p
3
1k87*
1
10n
4
2k2
1
100n
2
3k32
4
10k
1
Active
Components
15k
3
1N4148
4
23k2
1
BC558
1
30k1
4
LM301
1
56k
1
2N3904
14
100k
3
2N3906
4
196k
1
2N3958
1
220k
1
Table 4 - 4012 VCF Core BOM
11.
Build the 4072 VCF Core. There are five matched transistor pairs (4x 2N5087 and 1x 2N3906).
Additionally, there is one thermally coupled NPN-PNP pair. Thermally couple the 1k87 tempco
resistor to the NPN-PNP pair.
Do not install the pin headers at the stage.
4072
Resistors
Sockets
100r
1
DIP14 socket
1
220r
9
DIP8 socket
1
1k
1
1k3
1
Capacitors
1k87*
1
4n7 (Film)
4
2k2
5
10n C0G
1
4k7
1
10k
3
Capacitors (electrolytic)
12k1
7
10u
4
13K
3