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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>well, I see a sort of
sawtooth with a flattened top (about 5 v p-p, centered at 12.5 v) at pin 5 of
U2. just for the heck of it i replaced D1 and D2, but see the same result.
bummer. </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial size=2>C7 should be 33pF, right?</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial size=2>what voltages do you get for the gate
CV?</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> David Moylan
[mailto:dave@westphila.net]<BR><B>Sent:</B> Tue 3/8/2005 9:27 AM<BR><B>To:</B>
Schierl, Dan<BR><B>Cc:</B> synth-diy@dropmix.xs4all.nl<BR><B>Subject:</B> Re:
[sdiy] fun with KBD2e<BR></FONT><BR></DIV>
<DIV>I put one of these together, and I also found some discrepencies, but
nothing that prevented me from getting it working correctly. I believe you
should have a high frequency clock being fed into U3 and on the output, but the
associated diodes/cap on the output should be rectifying/smoothing this into
DC. Check the signal input to U2 and see what you have there. Maybe
check the polarities on your diodes, D2, D1?<BR><BR>Dave<BR><BR>Schierl, Dan
wrote:
<BLOCKQUOTE cite="" type="cite">
<DIV><FONT face=Arial color=#000000 size=2>hi list--</FONT></DIV>
<DIV><FONT face=Arial size=2>has anybody had any experience with
TomG's keyboard converter, the kbd2e? I recently put one of these
together, and am getting some strange results. </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>documentation is here:</FONT></DIV>
<DIV><A
href="http://www.ele4music.com/pdfs/kbd2e.pdf">http://www.ele4music.com/pdfs/kbd2e.pdf</A></DIV>
<DIV> </DIV>
<DIV>I noticed 4 or 5 discrepancies between the schematic and the pcb, and i
believe I have corrected these. also, i noticed 2 discrepancies between the
parts list and the schematic, and I think I got those right as well. the pitch
CV out seems to be working fine, but the Gate out is acting weird--with key up
I see about 14 volts, and with key down I'm getting a ~4volt p-p square wave
centered around 12v, and from what i can see it has a frequency of around
50 KHz. tracing back a bit i'm reading a 30V p-p square wave on pin 5 of U3 (a
13600) at the same frequency.</DIV>
<DIV> </DIV>
<DIV>any thoughts as to what i should check
next?</DIV></BLOCKQUOTE><BR></DIV>
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