schematic: 606 voice-change

[Tom Verheyden]

Hello synth-diy'ers

There where some people who've mailed me about the 606-mod's I've done.
Since my computer found it necessary to mix-up al my mails, I couldn't find
out who've mailed me about this subject
BTW: anyone have adress from Bojan Burkeljc..., I've to mail him about some
problems with his MS20, but my computer wiped out his adress (DAMNED!!!
Stupid School Things :-))
Anyway I have the schem extracted from a mail from mr808 in 1995.

begin:

FIG. 11:    --------/\/\----------
            |        R2          |
            |                    |
            |---||----+----||----|
            |   C1    > R1 C2    |
            |         <          |
            |--|\     v GND      |
               |  \______________|____  Periodic wave out
               |  /
Pulse in ------|/

f = 1/(2pi*SQRT(R1*R2*C1*C2))

Q = SQRT(R2/R1)/(SQRT(C1/C2)+SQRT(C2/C1))

The bridged T-network filter shown in Fig. 11 is used to generate
periodic damping drum sound.  This configuration has variations according
to application (instrument sound).  Values of R and C can be changed.
With this circuit, the decay time becomes longer as Q increases.

end of mail

It was normally designed for a TR-808. 
I've used 10nF caps for C1 and C2 and first replaced R1 and R2 by pots to
determine the correct value by measurement; Then I've placed normal
resistors in place.
You can also let the pots in the circuit and change the voice while you're
playing....

ENJOY


Tom,

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*                                              *
* Da funk back to the punk      _____ Daft Punk*
*                                              *
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* Tom Verheyden @ KHK Geel Belgium             *
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* h5020503 at pophost.khk.be                      *
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