I keep postponing writing the build log of these modules, but here’s the 4th module in my rack, a Magnus Danielson design sawtooth phase shifter which is really an extension of the sawtooth octave doubler design on the same page. Magnus created these schematics 10 years ago to be as simple as possible, and this particular one contains an error which you should fix if you want to build this module. You’ll have to figure out for yourself, though…
I also broke out the internal comparator, which could be used to make a PWM easily.
As always, here’s a video of me playing around with the module, with an oscilloscope so you can see the waveform. Please turn on 720p for slightly better audio quality. (Should already be on by default in this embedded player.) There’s a bunch of annotations throughout the video explaining what I’m doing.
The next module I’m planning to build… Will probably be a cool one, so stay tuned.
Here’s an update, without a big write-up yet. I’ve added two modules to my panel.
1) An ADSR envelope. In itself a pretty boring video, but you can only do so much with a VCO, an ADSR and a bench-top sine generator without a voltage-controllable frequency.
2) The XR-VCO. This is where it gets interesting.
XR-VCO - Cross-modulations (Lots of annotations explaining what’s going on.)
XR-VCO - Sync+linear FM. (No annotations explaining what’s going on yet, but some phat sounds.)
I’ve also added another panel with 4 straight tele <-> banana converters (no buffering or level-shifting or anything) and a power module, so I can use a regular AC adapter to power the thing, rather than a bench-top power supply. I’ll post pictures and a write-up of the build later.
So here’s the deal. A couple of years ago a friend of mine introduced me to the world of modular synthesizers at a school where he was enrolled, where they had a pretty big, original ’70s Serge with cherry-picked set of modules (I’m assuming) as well as an original Buchla 200 series system from that era. I like the sound of the Buchla oscillators, but in all other aspects, I’ve fallen in love with the Serge. You see, I’m an engineer type of person and I appreciate the atomic structure of the Serge paradigm. As for any Serge-lover of rank, my favorite module is the DUSG. You’ll have to look long and hard for a more versatile module. If I could build a rack consisting of several pieces of only one type of module, that would definitely be it.
So, I quickly learned the basics of knob twiddling and banana sex, () but both me and my friend had the problem that we didn’t have our own modular systems. Using a fully equipped system at an institution is great, except that you need to actually go there etc. The next logical step is obviously to get our own synths. He is a lucky bastard who happens to have a rich mom, with the effect that he has bought 1-2 modules a month for two years straight. He now has 9U or so worth of Euro.