<html><head></head><body><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 size="2" face="Arial" id="yui_3_16_0_ym19_1_1483995648311_12069"> On Sunday, January 1, 2017 6:24 PM, Richie Burnett <rburnett@richieburnett.co.uk> 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 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 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 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 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></div> </div> </div> </div></div></body></html>