First Posted Feburary 24, 2016
Updated March 27, 2016

When I was using Orcad V9.2 to do my schematics, I created a library of parts and circuit blocks that I used all the time.  The one problem with Orcad is that nobody else, for all intents and purposes, was using it.  And, I can't blame them.  OrCad is really expensive.  However, with the release of KiCad Version 4, KiCad works well enough for me to be able to use it without quiting in frustration.  So I am gradually moving every thing ofer to KiCad so that it can now be 100% open source.

Disclaimer:  Everything you find on this page is Open Source.  And while most of these are tried and true circuits, they have been all redrawn in KiCad.  So for the time being, you really should consider them all untested until the circuits can be verified by actually making a PCB from them.

Also, please note, the the components in the library were done initially from memory.  My memory is not as impecable as it was.  However, as I use this library, problems are being fixed.  From March 27 on, I am hoping that the problems are few and far between.  I have also renamed the library file.

    Schematic and PCB Footprints Library  Updated March 27, 2016

    Circuit Blocks    Updated at  March 27, 2016

March 7, 2016

    In this update, there are some new componts in the libraries and some corrections.  I think I finally have the TO92 footprint and the schematic symbols that use it now correct amd cpmsostamt/  This includes the DUAL_2N3904, DUAL_2N3906, LM78L05, PNP and NPN.

    I have also added two new circuit modules.  Both do the same function.  They are MidiMerger5U and MidiMerger4U/EURO.  The later is still undergoing revision, but the former I am pretty sure is ready to generate gerbers and send out, or real close at least.

    Here is a "Catalog" of schemtics that are in the Circuit Blocks.

    MIDI MERGER (5U version)

    Based on the ATMega1284, in a 40 pin DIP package, this ciruict features four expansion ports that break out the unused pins on the chip so that future hacking can easily be done.  This includes 8 analog inputs so that in theory you could add 8 control knobs that will also mix control messages into the midi stream.


    This VCO was designed by Scott Bernardi and myself and it was officially working on Feb 1, 2003.  You can find info on this elsewhere on this website.  The VCO core oscillator was designed by Terry Michaels and info about it can be found in some of the earlier issues of Electronotes.  Primarily what Scott and I added to the oscillator was the active temperature compensation.  I came up with the variable gain amplifier, Scott came up with the band gap thermometer.  I still have the original boards that had the first version of the oscillator that was built back in 2003 and to this day it has never needed to be retuned.


    This is the analog portion of an ADSR Envelope Generator.  The logic is not present.  Generally, I implement this in a micro controller of some sort.  My personal favorite is the ATmega328.  But you can use any other micro controller, or even just plain old ordina HC logic.  The ADSR requires three states.  The idle state is the RELEASE_STATE.  It will remain in this state until the logic recieves a GATE signal.  Then we go into the ATTACK_STATE.  In this state, the output of the ADSR will be heading towards about 13 volts.  But before it gets there, the comparator is tripped and lets the logic know that it needs to now be in the SUSTAIN_STATE.  The ADSR will remain in the SUSTAIN_STATE until the GATE signal returns to inactive.


This is very much like the ADSR, but has a total of four states, and it allows you to set the levels of Attack and Seg1 and Seg2.

Midi Controller