It’s been awhile since I let anybody know how things were progressing with this. Almost two years, I’ve been busy and a lot has happened since my first post in September 2014. For those who remember my post from back then, here’s an update. For those who don’t, I’ll try to bring you up to speed.
Anyway, I had been working on a filter board based on the Korg 700S for awhile. It was using the firmware settings for the Dual SVF gilter to change filter responses and routing. Eventually, I had to take a break from it because I had too much happening in my personal life. When I finally was able to start work on it again, I found that an OS update had made a lot of the work I had done on my computer inaccessible. I salvaged what I could and worked my way through that. I had some boards made, and found that I had missed a few careless errors. So those boards were unusable for anyone who doesn’t want to do a lot cutting of traces and soldering wire jumpers.
Earlier this month, I finally was able to get those errors corrected and new boards made. I’ve made one, and it works great:)
Here’s a quick rundown:
It has the same functionality as the Dual SVF board but includes only very easy to find parts. (However, there are a lot of them.) I don’t have a Dual SVF to compare it to, but from the demos I have heard. The character is significantly different.
It is not meant to be a clone of any existing design, but it is based largely on the diode ring filters of the Korg 700S and Korg MS-50. The VCA is based on early Korg designs as well.
SKF stands for Sallen Key Filter, but I decided to informally call it “Three Ring Circuits” for a few reasons. First of all, it has three diode rings (One for each filter, and another for the VCA), and obviously “circuits” sounds like “circus”. It’s also a bit of an homage to the early Human League song “Circus of Death” which prominently features the Korg 700s. In keeping with this theme, I changed the ghost to an evil clown.
If anybody is interested, I would like to offer the boards for sale once I’ve sorted out the details of how to handle that. I’d feel bad about selling the boards without a manual, so I would like to finish the manual pretty soon. I’m giving some consideration to putting kits together. That may be more work than I can handle though, so I don’t want to make any promises about that until I know I can keep them. I’ll let everybody know when I am ready. I expect it to be some time this month.
I’ve added a few new demos to my soundcloud page.
And here are a few pictures.