EFM Tomcat Manual

EFM
electronics for music
Tomcat
TomCat Midi Synthesizer
The TomCat is specifically designed to be built by anyone with a little kit building experience. It features simple single
board construction with no wire flying to the board. Minimum parts make it a breeze to assemble. All connections to the
board are made through three headers, a 1/4" output jack and a AC power jack.
The control package is much like the TB except I swapped a keyed AD envelope generator for the TB's decay generator
and accent functions. This particular change in design allows the TomCat to be much more playable using a keyboard
controller.
If I had to declare lineage, I would say it's based on the ARP Axxe however I didn't use any of the original circuitry. It all
starts out about the same place but ends up somewhere completely different.

The Controls

Glide - Is keyboard controlled and activated by holding
down any two keys.
Tune - Raises or lowers the pitch.
Mix - Mixes Sub-generator and VCO output to the VCF.
Cutoff - Sets the initial VCF cutoff frequency.
Res - Adjusts the amount of ringing - it will self oscillate.
Env - Sets the AD envelope generators level to the
VCF.
Attack - Adjust the time it takes for the envelope
generator to charge.
Decay - Adjust the time it takes for the envelope
generator to discharge.
Volume - Overall level.
Midi Select - switch settings
0000 = 1 1000 = 9
0001 = 2 1001 = 10
0010 = 3 1010 = 11
0011 = 4 1011 = 12
0100 = 5 1100 = 13
0101 = 6 1101 = 14
0110 = 7 1110 = 15
0111 = 8 1111 = 16
Header 1 is power switch/LED LED1
LED1
SW1
SW1
Header 2 is control-out/DAC scalePitch
Header 3 is DC power -12V
Header 4 is audio out
GND
Output
(c) EFM ele4music.com
Gate
Glide
Accent
V-Ref
P.Bend
GND
+5V
+12V