View source for Ken Stone/1973 classic Serge/Serge peak and trough

[[File:cgs_serge_peak_and_trough_panel.jpg|thumb|center|114px|]]
The following info on the 1973 variant of the '''Peak and Trough''' module is presented for educational/historic purposes only and are not to scale.

== How it works ==
[[File:cgs_serge_schem_serge_r3.gif|thumb|center|431px|]] 
Functionally it is remarkably simple. Diodes form the linear equivalent of 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 pull down to an appropriate voltage rail, while using another diode 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 substituted. 

== Construction ==
{| align="center"
| [[File:cgs_serge_peak_and_trough_pcb1.jpg|thumb|center|101px|PCB pattern]]||[[File:cgs_serge_peak_and_trough_pcb2.jpg|thumb|center|101px|PCB pattern and components]]||[[File:cgs_serge_peak_and_trough_pcb.jpg|thumb|center|102px|PCB component side]]
|}

'''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 

== CC-BY-NC ==
Readers are permitted to construct these circuits for their own personal use only. Serge Tcherepnin retains all rights to his work. 

== See also ==
* [[Serge Modular Music System]] 

== References ==
* [https://web.archive.org/web/20161004090804/http://www.cgs.synth.net/synth/serge/peak_and_trough.html Some info on the 1973 variant of the Peak and Trough module.] (archived) by Ken Stone, 1999, with permission of the author 

== External links ==
* [http://www.serge-fans.com/index.htm Egres - The unofficial Serge web site]
* [http://groups.yahoo.com/group/cgs_synth CGS Synth discussion group], for discussion of locating parts, modifications and corrections etc.

[[Category:Ken Stone's 1973 Serge]]