<div dir="ltr"><div>Here is a little update to this topic.</div><div>Some good people at GS have photographed the VCF section on two behri 2600 versions: orange/black and grey.</div><div>You can see that in orange, they used SMD ceramics, and on grey, yellow box film.</div><div>Lucky for us, the orange version has empty through-hole footprints!</div><div><a href="https://www.gearslutz.com/board/attachments/electronic-music-instruments-and-electronic-music-production/953304d1616358816-behringer-2600-a-2600vs2600.jpg">https://www.gearslutz.com/board/attachments/electronic-music-instruments-and-electronic-music-production/953304d1616358816-behringer-2600-a-2600vs2600.jpg</a></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jan 18, 2021 at 11:49 AM ColinMuirDorward <<a href="mailto:colindorward@gmail.com">colindorward@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div style="margin-left:40px">
Was there an audible difference between the two capacitor types with the same frequency/resonance <br>
setting on the filter? <br></div><div style="margin-left:40px"><br></div><div>If this question was for me, then here is my answer: In my 4pole 3320 BPF, the polypropylenes sound slightly better. The obvious difference is that at lower frequency settings, they go into self-oscillation more readily than the ceramics. To my biased ear, the ceramics make some small distortion perhaps, or for some reason add a slight edge to the sound. I did do a blind test using a 2pole 2164 SVF and the difference there is more noticeable than in any other filter I've tested. Here, the polys are a clear win. I want to use words like "liquid, juicy, lush" for the polys vs "bite, edge, grit" for the ceramics. However those are too strong words to describe a very subtle difference. I am waiting to find the right modern mono synth that I can do a capacitor "upgrade" on and test if it's possible to perceive a change in the sound in a factory-made unit. I have an uno synth on the way (was on sale for $135cad?!), perhaps I'll be lucky enough to find space inside that tiny case for four WIMAs. <br></div><div><br></div><div>I also would like to add a big thanks for all the conversation on this topic! Every time I say the word "capacitor" around here, I learn so much! Last time it was about bypass caps, and now this topic as well has been very good reading.</div><div><br></div><div>Cheers,</div><div>Colin<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sun, Jan 17, 2021 at 9:36 PM Tristan <<a href="mailto:tu@alphalink.com.au" target="_blank">tu@alphalink.com.au</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Was there an audible difference between the two capacitor types with the same frequency/resonance <br>
setting on the filter?<br>
<br>
/Tristan<br>
<br>
On Mon, Jan 18th, 2021 at 11:19 AM, Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" target="_blank">mbryant@futurehorizons.com</a>> wrote:<br>
<br>
> Agreed lead inductance would be tiny. I was thinking more of inductive<br>
> coupling between the lead inductances if the capacitors are mounted close<br>
> together, or close to a high level signal. This can easily happen in the MHz<br>
> range and adversely affect the audio performance.<br>
> <br>
> -----Original Message-----<br>
> From: Synth-diy [mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a>] On Behalf Of<br>
> Gordonjcp<br>
> Sent: 18 January 2021 00:07<br>
> To: <a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a><br>
> Subject: Re: [sdiy] VCF caps in modern synths<br>
> <br>
> On Fri, Jan 08, 2021 at 03:29:44PM +0000, Mike Bryant wrote:<br>
> > <br>
> > >Yesterday I did some very non-scientific testing of 3320 4pole BPF built<br>
> using C0G vs polypropylenes. The test may have been more about the tolerances<br>
> of the caps rather than the dielectric, since my polys are 2.5% vs the C0Gs<br>
> at 5%. I noticed that at lower frequencies, the polypropylene version would<br>
> go into oscillation before the C0G version. Any thoughts on this?<br>
> > <br>
> > Was this SMD or through hole ? It’s possibly down to lead inductance or<br>
> series resistance being higher in the C0G.<br>
> > <br>
> <br>
> Lead inductance would be tiny, negligible at audio. If your VCF is<br>
> oscillating in the low GHz range you might have issues.<br>
> <br>
> -- <br>
> Gordonjcp<br>
> <br>
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