The following are presented for educational/historic purposes only and are not to scale. These designs are copyright Serge Tcherepnin.

Some info on the 1973 variant of the Peak and Trough module:

• pcb pattern
• pcb pattern and components
• pcb component side
• schematic

Functionally it is remarkably simple. Diodes form the linear equivalent of an an OR gate or an AND gate. There is a 0.6V voltage loss across the diodes. This is followed by a complementary emitter follower which loses 0.6 volts in the opposite direction, thus compensating for the loss in the diodes. A constant current source acts as a pull-up or pull-down for the emitter follower. The "no inputs" base state is derived from a resistor pull-up or pulldown to an appropriate voltage rail, while using another diode to to clamp it to either 6 volts (trough) or 0 volts (peak).

FD6666 diodes were used, though any common silicon signal diode would do. Generic general purpose silicon signal transistors can be subsituted.

PCB connections:
A = Peak input
C = Peak input
B = Peak input
D = Peak input
E = Peak output
F = Trough input
G = Trough input
H = Trough input
I = Trough input
J = Trough output
W = 0v
X = +12v
Y = +6v
Z = -12v

Classic Serge