I’ve decided to start selling these on ebay to raise some money for parts. Here’s a link to the current auction… and here’s a photo of the current model:
Here’s a revised schematic showing additions/changes, as well as a parts list:
Here’s a video of Mimsy, Phoenix, the Modutronic Messmaker, and the Dirty Cow amp all making noise together, along with the Blue Lantern filter:
So, the plan for the 567 changed a little bit. Meet the Modutronic Messmaker- I added a 555 oscillator to make it a synth (with audio input for the AM part). Here’s the schematic:
I actually used 2.2k pots where 5k’s are specified in the schemo (more scavanged parts). Here’s what the final circuit looked like before going into a case:
I recently came across a plastic VHS tape case, so that became the housing.
There are a total of four jacks- from left in the above picture: 555 CV in, 555 output, 567 AM (pseudo-ring mod) in, 567 out. The inputs use switched jacks, so when nothing is plugged into them, they receive input internally. With no inputs, the 567 is fed from the 555 output, and the 555 CV input is fed from the 567′s output. There are controls for the frequency of each osc, voltage starve, 555 CV input level, 567 output level, and a control for the frequency of the 567′s simple filter.
Here’s a video of the Messmaker in action:
Once again, thanks to Beavis Audio Research- this time it’s a tremolo/quasi-ring modulator circuit built from the LM567 tone decoder chip. As an added bonus, the squarewave oscillator also works on its own, without any input. Click here to view the pdf from the Beavis audio site (includes schematic and breadboard layout). This chip was traditionally used for touch-tone decoding in telephone & other communication systems (I recently harvested two of them from an old modem), and includes an internal oscillator and bandpass filter. Here’s what the circuit looked like on the breadboard:
And here’s a shot of the final perfboard build:
I made substitutions for the filter and volume pots: instead of a 50k on the filter and 100k on the volume, I used a 22k for the filter, and a 50k for the volume- the original 50k on the filter seemed to have a lot of extra travel (and so does the 22k, but I’ve got a few to use). The volume pot sub was just because I had no 100k audio-taper pots.
Here’s a recording of the circuit being fed with the APC side of Mimsy Modular:
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My original thought was to make this into another module for the Phoenix project, but now I’m leaning towards just making it a stand-alone fx/noise box. Since there is so much extra room on the board, I’m thinking of adding a simple distortion circuit of some type on the output, which could be switched in & out.
