Do you only hear the clicking on the HP output when you're sweeping the cutoff frequency? Or do you still hear clicking even when the cutoff frequency and resonance of the filter are fixed? <br><br>-Richie,<br><br>Sent from my Xperia SP on O2<br><br>---- Benjamin Tremblay via Synth-diy wrote ----<br><br><span style="font-size: 14px;" class="">Hello alls, </span><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">I have a circuit I built twice and both times I have this issue with a VCA produces a loud click (with with a slow-ish envelope attack) but only when I use a specific sound input.</div><div style="font-size: 14px;" class="">It uses a state variable filter I pulled almost verbatim from here: <a href="http://www.soundsemiconductor.com/downloads/AN701.pdf" class="">http://www.soundsemiconductor.com/downloads/AN701.pdf</a></div><div style="font-size: 14px;" class=""></div></body></html>
<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><div style="font-size: 14px;" class=""></div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">I am using the ALFA AS2164.</div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">From there I use the other 2 2164 stages to have a voltage-controlled mix of HP and LP. </div><div style="font-size: 14px;" class="">And from there I use the AS3360 VCA, one for a VCA and one for voltage-control of the filter resonance.</div><div style="font-size: 14px;" class="">Again, the VCA circuit is close to the reference implementation, with a quad op amp handling buffering. </div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class=""></div></body></html>
<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="font-size: 14px;" class=""></div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class=""><b class="">So, what’s the problem? </b></div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">The problem is consistently I hear the click on the VCA when I use the high-pass filter, which is bad because it’s for “high-hat” percussion sounds. </div><div style="font-size: 14px;" class="">If I route the low-pass filer into the 3360 VCA, it sounds great, even when I apply aggressive cutoff and resonance and crank up the mixer. </div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">Would a buffer or inverter fix this? Would a decoupling capacitor fix this (bias voltage) ? Or, is it very-high-frequency noise coming off the high-pass line (would passive filtering help?). </div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">The fact that this circuit consistently causes this problem has me scratching my shapeless, lumpy head.</div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class="">Ben</div><div style="font-size: 14px;" class=""><br class=""></div><div style="font-size: 14px;" class=""><br class=""></div>