<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=us-ascii" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.23588"></HEAD>
<BODY>
<DIV dir=ltr align=left><SPAN class=732225517-10042018><FONT color=#0000ff
size=2 face=Arial>All I could see of the patent were the figures, but based on
that, it looks a lot like what happens in the Dixie. All of the "modes"
shown in the final figure could be obtained simply by duty-cycle control of
the driving square waves in a tri-square oscillator.</FONT></SPAN></DIV><BR>
<BLOCKQUOTE
style="BORDER-LEFT: #0000ff 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"
dir=ltr>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> Synth-diy
[mailto:synth-diy-bounces@synth-diy.org] <B>On Behalf Of </B>Rutger
Vlek<BR><B>Sent:</B> Tuesday, April 10, 2018 6:34 AM<BR><B>To:</B> Tim
Parkhurst<BR><B>Cc:</B> synth-diy@synth-diy org<BR><B>Subject:</B> Re: [sdiy]
Continuously variable waveshaping (was Behringer Neutron)<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV dir=ltr>
<DIV>I recently stumbled on this recent patent by Moog: <A
href="https://patents.google.com/patent/US20160335998A1/un">https://patents.google.com/patent/US20160335998A1/un</A></DIV>
<DIV><BR></DIV>
<DIV>It concerns continuously variable waveforms, but implements it at the
core of a VCO rather than by crossfading the outputs (waveshapers) of
one. The idea is awesome, but I have my reservations about the real-world
feasibility of the method (given component tolerances and accuracies).</DIV>
<DIV><BR></DIV>
<DIV>Rutger</DIV>
<DIV><BR></DIV>
<DIV><BR></DIV></DIV>
<DIV class=gmail_extra><BR>
<DIV class=gmail_quote>2018-04-08 21:09 GMT+02:00 Tim Parkhurst <SPAN
dir=ltr><<A href="mailto:tim.parkhurst@gmail.com"
target=_blank>tim.parkhurst@gmail.com</A>></SPAN>:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>
<DIV dir=ltr><SPAN
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; DISPLAY: inline; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial">"
'High </SPAN><SPAN
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; DISPLAY: inline; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial">frequency
hash' is a direct quote from Ken Stone's description of that</SPAN><BR
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial"><SPAN
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; DISPLAY: inline; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial">circuit,
by the way."</SPAN>
<DIV><SPAN
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; DISPLAY: inline; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial"><BR></SPAN></DIV>
<DIV><SPAN
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; DISPLAY: inline; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial">-
and the band name for my new EDM / free jazz group. </SPAN></DIV>
<DIV><SPAN
style="TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); FONT-STYLE: normal; TEXT-INDENT: 0px; DISPLAY: inline; FONT-FAMILY: arial,sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(34,34,34); FONT-SIZE: 12px; FONT-WEIGHT: 400; WORD-SPACING: 0px; font-variant-caps: normal; font-variant-ligatures: normal; text-decoration-style: initial; text-decoration-color: initial"><BR></SPAN></DIV>
<DIV><BR></DIV>
<DIV class=gmail_extra>
<DIV>
<DIV class=m_6681943215784096788gmail_signature
data-smartmail="gmail_signature">
<DIV dir=ltr>
<DIV>
<DIV dir=ltr>Tim (add in some corned beef and you've got a tasty breakfast)
Servo<BR>---<BR>"Imagination is more important than knowledge." - Albert
Einstein<BR><BR><BR><BR></DIV></DIV></DIV></DIV></DIV>
<DIV>
<DIV class=h5><BR>
<DIV class=gmail_quote>On Sun, Apr 8, 2018 at 11:36 AM, Guy McCusker <SPAN
dir=ltr><<A href="mailto:guy.mccusker@gmail.com"
target=_blank>guy.mccusker@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: rgb(204,204,204) 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote><SPAN>On Sun, Apr 8, 2018 at 6:54 PM, David G Dixon
<<A href="mailto:dixon@mail.ubc.ca"
target=_blank>dixon@mail.ubc.ca</A>> wrote:<BR>> My wavefolder (as
found in the Intellijel uFold) uses TL072, and doesn't<BR>> generate
"high-frequency hash". Also, I've achieved what looks a lot like
a<BR>> resonant filter output with a sawtooth wave, without a
filter. Given the<BR>> way that this folder works (with diode
"turnaround" circuits) I'm not sure<BR>> that slew rate is a
significant factor. The opamp outputs in the folder<BR>> chain
are confined to relatively small voltages -- the first one to about
3V<BR>> or less, and the subsequent ones much less. Other folders
may have<BR>> significantly different modes of operation where slew
rate is important, but<BR>> not the ones based on diode
turnarounds.<BR><BR></SPAN>There's a bit of talking at cross-purposes here
I think. The wave<BR>folder in the CGS29 and also the Serge wave
multiplier (middle<BR>section) also does not generate "high frequency
hash" and works fine<BR>with a fast op amp. Their design is also similar
to your "turnaround"<BR>idea, as it happens.<BR><BR>The "high frequency
hash" business concerns a different part of the<BR>CGS29, the Grinder
section, which exploits op amp overshoot and<BR>ringing. It makes sense
that slew rate is a factor there. ("High<BR>frequency hash" is a direct
quote from Ken Stone's description of that<BR>circuit, by the way.)<BR>
<DIV class=m_6681943215784096788HOEnZb>
<DIV
class=m_6681943215784096788h5>______________________________<WBR>_________________<BR>Synth-diy
mailing list<BR><A href="mailto:Synth-diy@synth-diy.org"
target=_blank>Synth-diy@synth-diy.org</A><BR><A
href="http://synth-diy.org/mailman/listinfo/synth-diy" rel=noreferrer
target=_blank>http://synth-diy.org/mailman/l<WBR>istinfo/synth-diy</A><BR></DIV></DIV></BLOCKQUOTE></DIV><BR></DIV></DIV></DIV></DIV><BR>______________________________<WBR>_________________<BR>Synth-diy
mailing list<BR><A
href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</A><BR><A
href="http://synth-diy.org/mailman/listinfo/synth-diy" rel=noreferrer
target=_blank>http://synth-diy.org/mailman/<WBR>listinfo/synth-diy</A><BR><BR></BLOCKQUOTE></DIV><BR></DIV></BLOCKQUOTE></BODY></HTML>