That 3U was just about there, but there was a signal discontinuity between the mono VCO and the stereo VCF. Fixed that with the Minsk, which lets the user adjust a mono signal into stereo...and natch, it's post-VCA and pre-VCF. Also, I went with the Veils due to the convenient "breakable" mixbus, as I wasn't sure that the Erica had that. But now, this lets the user use one of the Veils VCAs for signal-to-Minsk levels and then there's plenty left for the stereo output and that STILL leaves a VCA free for modulation level control. So here it is...
ModularGrid Rack