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KBD 2e - Keyboard Converter

 

Keyboard converter / interface. 
Features...

     

1 volt per octave control 
voltage

 

     

Key gate

 

     

Modulation LFO

 

     

Modulation VCA

 

     

Scaleable over 8 octaves.

 

     

+/-12 or +/- 15V

 

Requires one or two switch per 
key keyboard with a voltage 
divider of 1 resistor per key 
100ohm 1%.

Like most EFM modules the KBD2e is multi functional. It's primary function is to 
convert a cheap plastic keyboard into a synthesizer controller. It can be built on a panel 
and bolted in the rack or installed in the keyboard case.

Getting the keyboard can be a problem. The easiest to convert I have found so far are the 
four octave Casio's. Once you have one you can ether build it in the case it came in or 
remove the keyboard and build it a more useable new case.

Summary of Contents for KBD 2e

Page 1: ...ohm 1 Like most EFM modules the KBD2e is multi functional It s primary function is to convert a cheap plastic keyboard into a synthesizer controller It can be built on a panel and bolted in the rack or installed in the keyboard case Getting the keyboard can be a problem The easiest to convert I have found so far are the four octave Casio s Once you have one you can ether build it in the case it ca...

Page 2: ...plastic on the sides of the keyboard to mount it to another case Remove the screws holding the PC boards to the back of the keyboard Then remove the PC boards Save the screws and mounting hardware we will put the boards back on The keyboard is really a bunch of switches connected by a diode matrix We need a resistor chain so the diodes must be removed from the board and the solder pads cleaned The...

Page 3: ...mon point for all the switch pads to connect Solder the connection wires to the ends of the chain and the common point before you screw it back to the keyboard Attach a digital ohm meter to the common point and one end of the chain Press a key and measure the resistance It should be 100 ohms X the number of resistors between the pressed key and the end of the chain IE The lowest key should be 0 an...

Page 4: ...PARTS LIST Small Kit C1 C2 C9 0 1 3 C3 001 1 C4 6 01 3 C7 33p 1 ...

Page 5: ...10K 11 R3 R5 R12 R13 R14 100K 5 R7 100 1 R11 47K 1 R15 R17 390K 2 R18 R27 33K 2 R19 470 1 R20 R23 2 2K 2 R25 22K 1 R26 220 1 D1 D3 1N914 3 Q1 2N3819 1 Q2 2N3904 1 Q3 2N3906 1 U1 U2 U4 TLO72 3 U2 LM13600 1 Full Kit P1 1M 1 P2 50K 1 P3 100K 1 T1 10K 1 ...

Page 6: ... R23 2K2 R21 10K R22 10K P4 50K VCA Init R27 33K R28 10K Q3 2N3906 U2 1 2 3 U2 7 6 5 U3 5 4 3 U4 U4 1 2 3 7 6 5 Joystick P5 50K Mod Range P6 50K P Bend Range B C D E F G K L M N O P H Jump R17 I J VCA In VCA CV VCA Out Gate Out Pitch Out P Bend Out Mod Out Lag In KBD2E Keyboard Interface Converter 11 15 99 1 5 2001 Copyright 1999 2001 EFM A U3 13 14 16 12 10 9 C1 0 1uF C2 0 1uF 12V 12V S1 Gate Dis...

Page 7: ... B C E F K L M N O P H Jump R17 I J From LFO Tri Out Mod CV Mod Out Lag Out Lag In KBD2E to RXCV Expander Modifications 11 15 99 1 5 2001 Copyright 1999 2001 EFM U3 13 14 16 12 10 9 C1 0 1uF C2 0 1uF 12V 12V 3819 S G D 2N3918 E B C 2N3904 2N3906 1 4 5 8 1 8 9 TLO72 LM13600 5V VCO1 VCO2 VCO3 Range 1 Range2 Range 3 2 4 8 16 32 Sub 100ohm 1 X5 R 22K R 220 R9 10K R 2K2 R 10K R 10K P 50K VCA Init R10 3...

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