[sdiy] VCF caps in modern synths

[Brian Willoughby]

On Mar 23, 2021, at 16:28, Gordonjcp wrote:
> On Tue, Mar 23, 2021 at 03:15:53PM -0400, ColinMuirDorward wrote:
>> Here is a little update to this topic.
>> Some good people at GS have photographed the VCF section on two behri 2600
>> versions: orange/black and grey.
>> You can see that in orange, they used SMD ceramics, and on grey, yellow box
>> film.
>> Lucky for us, the orange version has empty through-hole footprints!
>> https://www.gearslutz.com/board/attachments/electronic-music-instruments-and-electronic-music-production/953304d1616358816-behringer-2600-a-2600vs2600.jpg
> 
> Interesting.  So are they selling a special version for the coke-addled audiophools who reckon that they can hear the difference between through-hole and SMD components?

Not every capacitor formulation is available in all package variations.

I happen to prefer SMD - not for sound but for convenience of manufacturing. However, certain kinds of capacitors that are ideal for Sample and Hold simply aren't available in SMD, so my PCB designs include placements for both through-hole and SMD. This way, I can try out the cheaper C0G to see if they hold as good as I need for the S&H refresh timing that I can achieve.

I'm going to guess that these PCB were made to handle both so that volume discounts on the board fab could be obtained. Then, if a particular filter needs through-hole it's available.

Brian