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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.

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. 😀

Holiday sale! Qbloop Selections I 50% off!

From now until the end of the year, Qbloop Selections I will be half off the normal $8 price tag.  Have some last minute shopping to do?  Check out the music page or go directly to CDBaby to download the album now.

(Note:  iTunes pricing isn’t something I can change.  Sale price only available at CDBaby).

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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The sound of my new bike

My new bike makes really cool samples.

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I recently purchased a new bike.  I love my new bike.  I love it so much that I’m sad when I’m away from it.  So I sampled all of the noises it makes, and wrote a new track using nothing but the pings from the frame, the swish of the pedals turning, the gentle clicking of the chain against the gears, the clacking and punch of the shifters, and a host of other little sounds, 41 in all.  The result is “Micycle.”  Enjoy.

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Micycle by sineqube