Small MS20 Filter PCB--Eurorack Ready

I am porting some old Frac Format synthesizer modules I built over the past few years....I am out of space in my studio so I want to port them to a slightly smaller Eurorack "skiff" format.  

Euro is still a bit new to me....but is the way of the present and future.  

Some design goals for these ports:

• Small footprint throughout
• Some SMD components but let's use through-hole where we can, so it's easy to build.
• Modular--so you can mix and match PCBs with future projects
• Want a stereo version?  Make two. Want a Quad version? Make four.  
• 100 mil edge connectors and minimal hookup wire

First up is a classic Korg MS20 filter clone based on the classic Rene Schmitz-bits layout. You can find Rene's interpretation about a million places on the Internet--LookMa has cloned this filter, LanterTronics has cloned this filter. I previously cloned this filter. 

Behringer may have cloned the "rene" interpretation of this filter for their K2?--don't know, but, knowing those guys--probably.

MS20 filter clone on the bench--Seems working!

Let's cut the blah blah ginger blah blah and get right to some useless build photos:

A happily bagged boardlette from this blog's sponsor--PCBWAY.  Please help out this blog and check 'em out for your next DIY project.

Op amps are SOIC SMD.  I can solder these without a microscope or magnifying glass....

Board layout.....  

Easy build....Ready to test!

Wiring used to test the design. The dots down the center are male 100mil PCB edge connectors.  

As an homage to Rene I used CA3080 OTA ICs; slightly hard to find but still out there, as of writing this post Jameco and Small Bear have them in stock....the design can be pretty easily ported to 13700 OTAs, an IC that is currently a bit easier to find; if there is interest comment below....but if you have skills with Eagle it would be pretty to grab eagle files off the PCBWAY community site and swap a 13700 into the sch and brd file yourself.

On the bench this small VCF board pretty much tested working first time....I didn't read my own notes on the previous Frac build (doh!) so I repeated a few of the same mistakes, but they were easily fixed. 

I have posted the gerber, PDFs, BOM, eagle files etc. on the PCB on PCBWAY's community page (here)....I hope to wrap this Euro port up in the next few weeks--I am currently finishing up a layout for a stereo pots n jacks board and a Euro formatted 14HP front panel. I will upload all those soon.  

Until then--don't breathe the fumes!