Moffenzeef STARGÆZER Drone Synth (DIY)
Jul 12, 2019 22:34:43 GMT
bearheadwood, spacedog, and 2 more like this
Post by NightMachines on Jul 12, 2019 22:34:43 GMT
Here’s a little quick and dirty DIY project I just finished. It’s an adaptation of the Møffenzeef Modular STARGAZER drone synth for the AE Modular.
Some info on the original desktop synth:
www.moffenzeefmodular.com/stargazer
The STARGAZER is open source and uses a Teensy 3.2 microprocessor for almost all its sound generation. The Teensy runs on +5V, so you can basically just plug it right into your AE Modular rack and it will work fine. Its analog inputs only accept 3.3V but it’s easy to scale the CV signals down to that with a voltage divider. To actually add CV inputs though, I needed to free up some analog input ports, which meant I had to leave stuff away. I decided to remove the output filter2, the output VCA and the three LFOs, which are all just standard features done in software. If I want another filter, a VCA and LFOs I can just use my other AE modules for that. I also did not implement the analog CMOS distortion, because I didn’t have the proper IC and also not enough space on my 2U PCB. But again, I can get that from another module.
So with analog inputs freed up on the Teensy, I added CV control for pitch, filter1 cutoff, wavetable selection, aliasing, bit reduction and sub oscillator octave switching, which turns the STARGAZER into a very different beast than the desktop synth. Now I can use it as a regular oscillator for melodies, with dynamic wavetable modulation. Awesome!
I built this in-between things over a few days, so it’s a really bad DIY hack-job, with a lot of potentiometer noise and I think one or two faulty CV inputs which I need to check. But it still works well and it’s a cool addition to my AE Modular rack.
Here are some demos:
Raw:
With the Nyle Filter and Lofi Delay:
... and a picture:
Some info on the original desktop synth:
www.moffenzeefmodular.com/stargazer
The STARGAZER is open source and uses a Teensy 3.2 microprocessor for almost all its sound generation. The Teensy runs on +5V, so you can basically just plug it right into your AE Modular rack and it will work fine. Its analog inputs only accept 3.3V but it’s easy to scale the CV signals down to that with a voltage divider. To actually add CV inputs though, I needed to free up some analog input ports, which meant I had to leave stuff away. I decided to remove the output filter2, the output VCA and the three LFOs, which are all just standard features done in software. If I want another filter, a VCA and LFOs I can just use my other AE modules for that. I also did not implement the analog CMOS distortion, because I didn’t have the proper IC and also not enough space on my 2U PCB. But again, I can get that from another module.
So with analog inputs freed up on the Teensy, I added CV control for pitch, filter1 cutoff, wavetable selection, aliasing, bit reduction and sub oscillator octave switching, which turns the STARGAZER into a very different beast than the desktop synth. Now I can use it as a regular oscillator for melodies, with dynamic wavetable modulation. Awesome!
I built this in-between things over a few days, so it’s a really bad DIY hack-job, with a lot of potentiometer noise and I think one or two faulty CV inputs which I need to check. But it still works well and it’s a cool addition to my AE Modular rack.
Here are some demos:
Raw:
http://instagr.am/p/Bz00iEno715
With the Nyle Filter and Lofi Delay:
http://instagr.am/p/Bz05Vdmodzd
... and a picture:
http://instagr.am/p/Bz1TcL-oDkW
The only downside of using a Teensy in the AE Modular world is the price, which is at least 20$. So this would drive the price of a commercial module up quite a bit.
