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<p>Yes, I agree -- THAT notes often need some detailed consideration
- they use some absolutely bizarre resistor values.</p>
<p>I actually used the AN120 idea basis with V2164 VCAs - took quite
a lot of multisim investigation first and then some physical
prototyping afterwards.<br>
</p>
<br>
<div class="moz-cite-prefix">On 09/01/2017 21:29,
<a class="moz-txt-link-abbreviated" href="mailto:microtonalsynthesis@yahoo.com">microtonalsynthesis@yahoo.com</a> wrote:<br>
</div>
<blockquote
cite="mid:1749230711.1456172.1483997356244@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial,
Lucida Grande, sans-serif;font-size:16px">
<div id="yui_3_16_0_ym19_1_1483995648311_12051"><span
id="yui_3_16_0_ym19_1_1483995648311_12146">Like many app
notes, the THAT AN120 is something of a DIY project in
itself. </span></div>
<div id="yui_3_16_0_ym19_1_1483995648311_12051"><span><br>
</span></div>
<div id="yui_3_16_0_ym19_1_1483995648311_12051"><span
id="yui_3_16_0_ym19_1_1483995648311_12405">The control
voltage inputs are reversed. U1 should use EC+ pin 2 and U2
should use EC- pin 3. </span></div>
<div id="yui_3_16_0_ym19_1_1483995648311_12051"><span><br>
</span></div>
<div id="yui_3_16_0_ym19_1_1483995648311_12051"><span
id="yui_3_16_0_ym19_1_1483995648311_12407">The breakpoint
generator is very sensitive to offsets and the circuit as
given has unequal volumes for left and right sides.
Adjustment of all resistors going to -15V is needed. I
estimate about 130.5K for the 133K. Of course, if you adapt
this circuit to 12V supplies then you need to adjust some
more.</span></div>
<div id="yui_3_16_0_ym19_1_1483995648311_12051"><span><br>
</span></div>
<div id="yui_3_16_0_ym19_1_1483995648311_12051">John</div>
<div class="qtdSeparateBR"
id="yui_3_16_0_ym19_1_1483995648311_12128"><br>
<br>
</div>
<div class="yahoo_quoted"
id="yui_3_16_0_ym19_1_1483995648311_12068" style="display:
block;">
<div style="font-family: HelveticaNeue, Helvetica Neue,
Helvetica, Arial, Lucida Grande, sans-serif; font-size:
16px;" id="yui_3_16_0_ym19_1_1483995648311_12067">
<div style="font-family: HelveticaNeue, Helvetica Neue,
Helvetica, Arial, Lucida Grande, sans-serif; font-size:
16px;" id="yui_3_16_0_ym19_1_1483995648311_12066">
<div dir="ltr" id="yui_3_16_0_ym19_1_1483995648311_12070"><font
id="yui_3_16_0_ym19_1_1483995648311_12069"
face="Arial" size="2"> On Sunday, January 1, 2017 6:24
PM, Richie Burnett
<a class="moz-txt-link-rfc2396E" href="mailto:rburnett@richieburnett.co.uk"><rburnett@richieburnett.co.uk></a> wrote:<br>
</font></div>
<br>
<br>
<div class="y_msg_container"
id="yui_3_16_0_ym19_1_1483995648311_12065">You could
always generate the two VCA control signals with the
appropriate pan law using a micro... Low cost pic with
dual output PWM perhaps? Pre-calculated values in lookup
table on a low end micro, or use quadratic fit
approximation if you're already using a dspic.<br
clear="none">
<br clear="none">
-Richie,<br clear="none">
<br clear="none">
Sent from my Xperia SP on O2<br clear="none">
<br clear="none">
---- Tom Wiltshire wrote ----<br clear="none">
<br clear="none">
>That's a fairly involved circuit, but I don't think
I've ever seen an analog panner with a switch to select
different pan laws. Very impressive!<br clear="none">
><br clear="none">
>I'll have a look over it and see if I couldn't use
the gist of it in a simpler way.<br clear="none">
><br clear="none">
>On 1 Jan 2017, at 20:14, Tom Bugs <<a
moz-do-not-send="true" shape="rect"
ymailto="mailto:admin@bugbrand.co.uk"
href="mailto:admin@bugbrand.co.uk">admin@bugbrand.co.uk</a>>
wrote:<br clear="none">
><br clear="none">
>> Not LM13700 based, but the details within the
THAT app note here may be some use:: <a
moz-do-not-send="true" shape="rect"
href="http://www.thatcorp.com/datashts/dn120.pdf"
target="_blank">http://www.thatcorp.com/datashts/dn120.pdf
</a>(VCAs in pan pot apps)<br clear="none">
>> <br clear="none">
>> <br clear="none">
<br clear="none">
>>>>> -----Ursprüngliche Nachricht-----<br
clear="none">
>>>>> Von: Synth-diy [mailto:<a
moz-do-not-send="true" shape="rect"
ymailto="mailto:synth-diy-bounces@synth-diy.org"
href="mailto:synth-diy-bounces@synth-diy.org"
id="yui_3_16_0_ym19_1_1483995648311_12086">synth-diy-bounces@synth-diy.org</a>]
Im Auftrag von Tom<br clear="none">
>>>>> Wiltshire<br clear="none">
>>>>> Gesendet: Sonntag, 1. Januar 2017
18:07<br clear="none">
>>>>> An: <a moz-do-not-send="true"
shape="rect" ymailto="mailto:Synth-diy@synth-diy.org"
href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a><br
clear="none">
>>>>> Betreff: [sdiy] Panning with
LM13700<br clear="none">
>>>>> <br clear="none">
>>>>> Hi All,<br clear="none">
>>>>> <br clear="none">
>>>>> Happy New Year to everyone! Here's
hoping you all have a great year with<br clear="none">
>>>>> many (completed) synth projects.<br
clear="none">
>>>>> <br clear="none">
>>>>> I've got quick question - what's
the best way to do equal power panning (-<br
clear="none">
>>>>> 3dB in the centre) with the
LM13700? I'm assuming that such a thing has<br
clear="none">
>>>>> been done already, so it's seems
silly to reinvent the wheel, but I can't<br clear="none">
>>>>> find anything that isn't a simple
linear crossfade (which is ok for<br clear="none">
>>>>> crossfading, but not so good for
panning).<br clear="none">
>>>>> <br clear="none">
>>>>> Any tips/pointers appreciated.<br
clear="none">
>>>>> <br clear="none">
>>>>> Thanks,<br clear="none">
>>>>> Tom<br clear="none">
<br clear="none">
<br clear="none">
<div class="yqt5154846973" id="yqtfd23478"><br
clear="none">
</div>
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