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Updated Stupid Box schematic

I’m enjoying the sounds this thing is making more and more.  I decided to put together a cleaner looking schematic in case anyone was interested in putting together one of these things.  Hope it’s helpful, and doesn’t contain too many errors.  The original post about the build has been updated, too.

This schematic omits the diode and replaces it with the 100 ohm resistor. Sounds better to me.

Stupid Box: How I learned to Stop Worrying and Love When Things Go Wrong

Stupid stupid box.

Audio demo of the Stupid Box

So, this last build was the most frustrating so far.  On the breadboard, I debated whether or not to even transfer it to perfboard and find an enclosure.  But, as it is the first synth I built from the ground up for use with my sequencer, I figured I should go ahead and complete it.

The synth itself is comprised of two chips, the 4046 and the 74C14.  The former serves as a basic square wave oscillator triggered from the CV out of the step sequencer, and the latter adds a couple more squares to modulate the first oscillator.  On the breadboard, it made some mildly interesting sounds, was pretty noisy, and I felt “meh” about it, overall.  I wanted to get it done fast so I could move onto the next thing.  I don’t like lingering on one project for too long.

I’m usually very meticulous and methodical about moving from the prototype to finalizing the build, triple checking every connection before soldering the components.  I even take multiple photographs from different angles of the breadboard, in case I get into trouble later.  This time, I also shot a little video, panning around the breadboard to make sure I could recheck working connections if something went wrong after soldering.

And tons of stuff went wrong.

I’m really not into 2nd drafts.  I want to do things right the first time, so I work slowly and try to make the end result as good as possible because I get extremely bored going over old material.  I’m the same way with music, writing, visual arts, nearly every creative endeavor — if I can’t do it quickly, I move onto something else as I have more ideas than time to complete them all.  This project, which I affectionately dubbed, “Stupid Box,” would test my patience in this regard.

Everything worked fine during prototyping, but that limbo between breadboard and final build where the project isn’t functional is incredibly stressful for me.  There exists that time where it doesn’t work, and you hope it can work again, assuming you build correctly.  I worked slowly, checked everything a bajillion times, and flipped on the power …

Nothing.

Strike that.  The battery started getting hot.  Not good.  Not good.  Polarity must be reversed on the clip.  Tried rewiring.  No joy.  Still getting hot.  Checked the direction of the electrolytics (even though I quadruple-checked as I built).  Everything looks good.  Checked the diode direction.  Looked fine.

I’m stumped.  And very frustrated.  I didn’t like this thing much to begin with, and now I started hating it.  I had a choice — keep trying to troubleshoot for a project my heart wasn’t in, or try and salvage the parts I could and move onto something else.  I had spent about a week off and on working on this though, and I hate failing.  I had to beat this Stupid Box, or I knew it would eat at me.

The hardest part about troubleshooting things like this is that it is usually some very small thing that’s simple to change, but it’s hidden.  From about a decade of working with Max/MSP, I was very familiar with this scenario.  I still hate it, but I’m familiar with it.  These problems tend to plague me for days on end and I have trouble focusing on anything else until it’s solved.

I scanned the perfboard for anything obvious.  I plugged the sequencer into the unit but kept the synth itself unpowered.  I could hear the clicking as the few volts the sequencer sent out coursed through the board and into the little battery-powered amp.  I poked and prodded every connection to check continuity, and see if I could inadvertently trigger something good to happen.  I was as much hoping for magic as science as my frustration grew.

Click click click click.  The four pulses from the sequencer didn’t change, and every time I plugged the battery in, it still got warm.  It was hard to check the issue when I couldn’t even get voltage into the system.

There!

Was that a little fleck of solder between the power and ground lines?  It was so small, that even with a magnifying glass, I had trouble telling if there was a connection.  I called my wife to come be another set of eyes.  Still too small to tell.  I fired up the iron and melted the solder enough to take a small knife and insure the separation of points.

Battery in.  LED on.  Success!

The project I was only mildly interested in was functional.  Yay.  : /

Other stuff went wrong too.  Things were shorting against the enclosure so I could only screw the circuit halfway.  The modulation section stopped working completely and after replacing two capacitors, a diode, and rewiring a solder joint that came loose, it ended up being one of the screws securing the board in place was shorting out a wire that was too close.  The mod section itself sounded way too faint in contrast to the output of the main oscillator.  When the photoresistor was engaged the filter pot acted in reverse.  And on and on and on.

So, this project has become an exercise in letting go.  It is yet another instance where I have to teach myself not to obsess over controlling every system I create.  As much as I have a deep love for generative work and aleatoric processes, I still default to wanting to be the puppet master.  Perhaps it’s because of this personality trait that I find generative systems so very Zen in my life.  It’s easy to be a Taoist when things are running smooth.  I need to carry it with me into the chaos.

I’m glad I built my Stupid Box.  It makes some decent sounds, especially after replacing the diode (see below).  I was even able to coax some vaguely formant synthesis sounding material out of it.  Time will tell how useful it is in the long run, but for now, I am pleased.  Here’s the mp3 demo again in case you missed it at the top:

Audio demo of the Stupid Box

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I’m including the hand-drawn schematic in case anyone wants to play around with this monster.  Yes, I know I need to digitize the layouts, but a crappy hand-drawn one is better than none, perhaps?

*Oh, I recommend replacing the diode with a 100 ohm resistor instead.  The mod section ended up sounding much more effective as a result.

Parts list - I would replace the 1N914 diode with a 100 ohm resistor
Loooottts of eraser marks. ; ) Build at your own risk. (And replace that diode with a 100 ohm resistor!)

Update 1.24.2011

Using an old version of Omni Graffle, I was able to put together a cleaner looking schematic.  Hope this is a bit more helpful to anyone looking to build one of these.

This schematic omits the diode and replaces it with the 100 ohm resistor. Sounds better to me.

Monotron+Sequencer+MiniKP = Joy!

Uploaded a new live performance demonstrating the main features of my new 4-step sequencer, and the recent modification to the Korg Monotron.  Finished up the housing last night.  Now, using only the sequencer, Monotron, Mini KP, and a Fender Mini Twin, I have a battery-powered mobile retro “analog” studio setup … thingy.  With blue lights.  And a snowman.  😀

Here’s a close-up of the sequencer:

It’s alive!!! Korg Monotron + DIY sequencer

I’ve been wanting to build a sequencer for a long, long time.  Once I saw the Korg Monotron, I knew it would be a perfect complement to a homegrown Baby 10 variant.  Still a beginner when it comes to circuitry, I figured I’d build a simple 4-step version to insure I could get it functioning correctly and perhaps later expand on it or build a bigger one.

A very tight squeeze inside the casing, but just enough room for an 1/8″ jack.

In opening up the Monotron, the labels for pitch, cutoff, gate, ground, etc. are clearly marked, and the mod and DIY community has done amazing things thanks to Korg’s willingness to share the schematic and present everything so accessibly.  I was planning on tapping into the pitch point on the board following the excellent work done at the Din Sync blog, as the main thing I’m interested in is being able to program melodic content on the Monotron rather than rely on the ribbon controller for input.  In my mind, this would elevate the unit beyond being a super fun toy, and into the realm of “serious” music making.  Some quick tests yielded less than favorable results in connecting the 4-step sequencer to the pitch and ground contacts, and I tried the gate point instead.  Surprisingly, this proved to be exactly what I was hoping for.  I’m sure more enterprising and better educated hackers, musicians, and electrical engineers could explain in more detail what was going on, but I held on to Rule #17 from Nicolas Collins’ Handmade Electronic Music:  “If it sounds good and doesn’t smoke, don’t worry if you don’t understand it.”  😀

So, if you’re trying to mod the Monotron simply to have pitch control via an external sequencer and don’t want to use something like Silent Way by Expert Sleepers to calibrate the dodgy pitch tracking, you may try tapping directly to the gate contact and bypassing the pitch contact altogether.  Worked for me.  Now, let’s just hope it doesn’t blow up.  😉

The sequencer itself features 4 pots for pitch control, 4 toggles for on/off selection of each step, a switch each for reset and pause, and a toggle to go from 4 steps to 3 to have the ability to switch to triple meter.  And of course, blue lights.  Runs off a 9v battery and not having to calibrate pitch with software plugins means I’m not tied to my computer, and really, who wants to do that when playing with something as mobile as the Monotron?

Anyone looking for more technical information regarding hacking the Monotron should definitely check out this thread.  Some great material here from people doing very interesting mods.

I’m including the crappy hand-drawn schematic (which probably has errors) and the parts list for the sequencer I built in case anyone wants to try making one.  It’s only the 2nd schematic I’ve ever drawn, so bear with me.  And if anyone has any suggestions for cheap/free software for the Mac to design schematics, let me know!

Messy, I know. Errors? Probably. Use at your own risk. 😉
Most of the parts are from Jameco. A few from Radio Shack. Easily obtainable.

Another homemade synth video

J & I playing around with the new homemade synth together. Running it through the Korg Monotron and Mini KP again. Great fun! 😀

Homemade synth video and 2 new tracks at Soundcloud

Just finished wiring up my new little 4-oscillator synth.  Still need to prepare an enclosure, but it’s working wonderfully so far.  It’s using a NAND gate Schmitt trigger IC (CD4093) and features 1 oscillator functioning as an LFO flipping between two others in the audio range.  Another oscillator is providing some fun cross modulation voodoo between the two main tone generators.  It also has a photoresistor that can alter the pitch of one of the oscillators (or be switched off via toggle), and some light low pass filtering.  And, of course, a blue light.  You can hear the result running through the Korg Monotron and Mini KP in the YouTube video below.  Not bad for a $0.29 chip.  😀

Also, uploaded two new tracks to Soundcloud featuring the same setup as listed above.  I’m enjoying seeing how much can be done with these little units, and I seem to be revisiting a minimal phase right now that is quite pleasing to me.  Nice.  Zen.

quadqube01 by sineqube

quadqube02 by sineqube

8-step sequencer & oscillator building

Productive day. Got the 8-step sequencer using the 555 timer and 4017 ICs running. Haven’t plugged it into anything yet, but am excited about the potential.

Also, played around with the Hex Schmidt Trigger IC to play two oscillators with a couple of photo resistors and my Altoid flashlight.

Anyone interested in this kind of thing should really check out Nicolas Collins Handmade Electronic Music. It is the most fun I’ve had in a long time. 😀

My first homemade synth

I built my first homemade synth -- Ray Wilson's Weird Sound Generator from musicfromouterspace.com

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I’ve started studying electronics.  Up until this point, I’ve been simply wiring together LEDs, buzzers, motors, and mucking about with programming the Basic STAMP microprocessor to hook up to my Max/MSP patches.  Ray Wilson’s Weird Sound Generator is my first foray into putting together something more complex.  It’s quite a nice kit for beginners and at the end of the process, one has a useful little noise maker in their arsenal of electronic instruments.

Since I found the documentation of building one at Matt Stanfield’s blog, the sync24 blog, and the image at Make very helpful when embarking on my own, I thought I’d pay it forward by posting images from my own adventure in circuitry in case it might help other people interested in making one.  I know that the hardest part for me was just starting the process as I was worried about making a mistake and blowing the $90 for the kit.  Sort of like staring at a blank canvas and daring to make the first brush stroke.  Seeing detailed images at the above links really facilitated the build for me.

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Separating out the resistor and capacitor values. Some of the color bands were difficult to make out. My multimeter is cheap and wouldn't register some of the values so I ended up using a flashlight to be sure of the colors.
Resistors go in first. Although I made a flashing bicycle light using perfboard, I'd never worked with a PCB before this project (except for some circuit bending). Great fun.
Shot of the back with the first few resistors. Later, I trimmed the ends a bit shorter.
After the resistors, the chip holders get installed.
Ceramic capacitors go in next.
Electrolytic caps, transistors, and diodes are the last to install (except for popping the chips in).
Separating out the potentiometers and getting ready to wire things up.
The lunchbox prior to routing out the holes. I picked this up at Old Navy for $8.
This hand reamer tool is very useful if you don't want to bust out a power drill, or if you're like me, your drill is a weak battery-operated thing. Thanks for the tip, Ri!
My wife had surprised me with a Dremel and it proved very useful for deburring the holes. Don't forget your safety goggles here!
Seating the circuit board. I was just testing the fit at this point. Ray even provides rubber stoppers and screws in the kit.Â
Making sure the pots and switches are seated correctly before soldering the wires between them and the board.
Shot of the back of the pots on the inside. The filter and resonance controls are wired (albeit a bit messily). I should've left more slack for these to try and help with shielding the wires from crosstalk. More on that later.
Welcome to the jungle.
Everything wired. This is right before switching it on to test it out. Fingers were tightly crossed.
And once again, a shot of the completed project. I had some extra switch covers from Radio Shack lying around that matched the theme nicely.

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There were a couple of glitches that cropped up once I had finished.  There seems to be some crosstalk from the filter and one of the oscillators resulting in an unintended clicking that goes away when I open the housing.  I’ve tried to shield the wires and resolder them so they were further away from one another, but it’s still present.  Also, the volume control mod only seems to reduce the volume on part of the sound.  Still, I was worried the project wouldn’t make any sound at all, so the fact that I have this cute lunchbox to make noise with is a success to me.

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You can check out a couple of mp3s of what it sounds like below …

wsg02.mp3 :  This example was recorded with the housing open, eliminating the clicking and restoring some volume functionality.

wsg01.mp3 :  Here, the housing is closed, bringing back the clicking.  If anyone has any suggestions on reducing it, I’d love to hear ideas.

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I highly encourage anyone interested in going down the hardware DIY path to check out Ray’s kit.  It’s quite fun and can be finished in a weekend.

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