praxidyke

Automatic Electric Starlite Phone

I recently purchased an Automatic Electric Starlite Phone for the purpose of using it as a microphone. I was also able to wire in the buttons to make the touch-tone noises. I wanted to be able to ring the ringer as well, but if this phone has a ringer (and it may not), I wasn't able to figure it out.

Small update, but I painted my case purple.

It needs a bit of touching up, but we'll worry about that later.

The mixer is working!

I also ordered an Automatic Electric Starlite Phone on ebay. I intend to turn it into a microphone. I'd also like to be able to ring the bell with CV, but I'm not sure if that'll work out. I think the solenoid is meant to run at like 100V? Unclear if it will be able to work at the +/-12V my powersupply puts out. Also concerned about the current draw. But I guess we'll find out soon.

I was waiting until I updated the code for this site before doing my next update, and that ended up taking a while. Oops.

Anyways, I've been busy. I successfully built a 2x VCA module. If I'm remembering correctly (and I may not be), it was based on David Haillant's Simple VCA. I also, built a 2x Ring Mod module based on this one from analog dot com, and rebuilt my 2x VCA module (and did a better job this time).

The 10 step sequencer and 20 channel mixer are both mostly complete, but need a considerable amount of bug fixing.

Since the last update, the following modules have come into my life:

• Two(!!) LFOs
• One(1) DSO 138 Mini oscilloscope
• One(1) wonky clock divider
• Two(!!) questionable VCAs
• One(1) stylophone

The LFOs are based on David Hailant's Simple LFO and are perfectly servicable.

The scope is great. No complaints. The panel I printed needs work, but it's a low priority.

The clock divider is based on the FONITRONIK Simple Divider. It behaves slightly strangely, for reasons that I have not been able to determine, but I think the irregularities could be fun.

The VCAs are based on this schematic I found on reddit. I think they work probably as well as they could. I also built this one by Moritz Klein, which I expect will work better. Once I get it to work....

The stylophone is comically bad, but technically works. I plan on making a better one eventually, but I had the idea in my head and I had to get it out. Maybe I should learn how to draw.

The first two modules are complete!

Getting here was an ordeal. The transformer that came with the case I ordered was cracked open, so I exchanged it for a new one. Which also came with a cracked open transformer. Thanks, Sweetwater. I kept this one and sealed it shut with wood screws. The plastic case around the transformer isn't really 100% closed, but it seems to work so far.

Also, I pulled a muscle in my back while moving my drill press. Fun times.

Anyways, I'm happy with the progress so far

I built the power supply. It turned out pretty good!

The next couple of projects will be a VCO, an LFO, and a sequencer. Not necessarily in that order.

I think the workflow for each module is going to look something like this:

1. Breadboard
2. "Desktop" Perfboard
3. Eurorack PCB

Most likely, I'll do several through the desktop phase before trying to make any full-blown eurorack modules. I haven't even bought a case yet. I think I'll get a case that comes with a power supply, and keep using the one I built for prototyping.

The 4700μF capacitors I bought have stubby little legs that won't fit into a breadboard, so I decided to skip that step and start with perfboard. The large perfboard that I ordered isn't due to arrive until tomorrow, so I decided to try to make everything fit onto the size board I already had.

Which was a mistake.

It was a mess. I think I probably shorted something, because the AC to AC power supply I was using stopped working. Nothing popped or smoked, the transformer just quit doing anything.

I cracked it open, and nothing looked wrong, so I put it back together and plugged it in again.

Which was a mistake.

This time, there were sparks. Apparently, if you break the factory seal, the transformer can fall out and hit the mains lines. Oops.

Anyway, the correctly sized perfboard and the replacement power supply should arrive tomorrow. At this point, it would have been cheaper just to buy a real eurorack power supply. But I suppose that's not really the point.

I have recently become interested in building modular synths. The first project will be the easiest: building the power supply depicted in this video by Moritz Klein.

The parts should arrive by this weekend.