MFOS Noise Toaster Lo-Fi Analog Synth – _electroidiot Version

The Noise Toaster is a Lo-Fi analog synthesizer circuit originally designed by the late Ray Wilson of Music from Outer Space and described in his excellent book "Make: Analog Synthesizers". To learn more about analog synthesizers, PCB, and product design, I built my own version of the Noise Toaster with a custom two-board "sandwiched" construction PCB layout and 3D printed enclosure. After getting the PCBs fabricated (which was kindly sponsored by PCBWay), I proceeded to build and analyze each part of the circuit.

Supplies

Autodesk Eagle for PCB design
Autodesk Fusion 360 for enclosure design
Adobe Illustrator CS2 for front-panel laser cutting and graphics design.
PCB Fabrication service from PCBWay
Laser cutting and 3D Printing services from Robu.in
Most components from musty old electronics parts stores in Lamington Road, Bombay
Some parts like 9mm vertical potentiometers from Tayda.
Soldron soldering equipment
Coffee
Country music for moral support

Step 1: PCB Design and Fabrication

This was my first major PCB design project. My goal was to make a more compact PCB layout than the existing design by Ray Wilson. I went with a two board "sandwiched" construction in which the top board contains the controls, and the bottom board contains most of the remaining circuitry. PCB fabrication was kindly sponsored by PCBWay. The process of uploading the Gerber files was easy and quick, and I was more than happy with the boards which they fabricated and shipped much faster than expected.

Step 2: 3D Printed Enclosure Design

The enclosure was designed to be compact and featured a snap-fit battery door. I also experimented with a snap-fit speaker grill. The enclosure design went through a few iterations until I finally settled on a size that accepted Eurorack 20HP plates.

Step 3: Power Supply and Audio Amplifier Circuits

More information about the power supply and audio amplifier circuits on the _electroidiot blog.

Step 4: Exponential Converter and VCO Circuits

Read more on _electroidiot.

Step 5: LFO Circuit

Read more on _electroidiot.

Step 6: AREG Circuit

Read more on _electroidiot.

Step 7: VCF Circuit

Read more on _electroidiot.

Step 8: VCA and WNS Circuits

Step 9: Final Assembly

The finished circuit boards were mounted on a laser cut front panel and installed onto the enclosure. Future plans include making a patchable version for use with a Eurorack system. Learn more about the Noise Toaster on the MFOS website. I also highly recommend Ray Wilson's book "Make: Analog Synthesizers" which goes into more details about the Noise Toaster as well.

Once again, a special thanks to PCBWay for making this project possible. I have used their services afterwards for some other projects as well and am very happy with the results and service.