Sunday, 27 June 2010

Ghetto Sequencer

4 step sequencer with vactrol VCO from concretedog on Vimeo.

So any free time this weekend has been spent creating this..Here we have a 4 step sequencer built from a 30p cd4017 chip and based on this schematic the clock input (tempo control) is provided by an oscillator built on a cd40106. At the moment its controlling a ghetto style VCO (the lower smaller circuit board) which is another oscillator built on a 40106 but being controlled by a hand hack vactrol, basically a light dependant resistor stuck to an led covered in copious amounts of gaffa tape!( I was going to use heatshrink as it is more lightproof but I didn't have any wide enough.) I've kept the different boards separate and have used an old IDE connector with its pins soldered into groups to act as a patch area....this is useful as I plan to build a few different modules and a few more VCO designs and this can serve as a test environment...before ultimately building a bigger sequencer (there's 10 steps available on each 4017!)

I'll post more as I add to it.
(BTW the audio in the vid above is just captured on the mic on my cam)

Sunday, 20 June 2010

Sounds from the Breadboard

I'm working hard, when I get the chance to, trying to make interesting synths and things from the CMOS range of chips I was talking about in the previous post.

Today I managed to get this beasty working (you know its getting a bit complex when you need a second breadboard!) So its 2 oscillators one controlling the clock/tempo of the sequencer and the other providing the sound...the sequencer is a pitch sequencer meaning each step is always on and you have some control of the pitch of the note.
I've added a duty cycle and a passive filter for some ghetto sound processing.

If you're a purist you may want to check out the first raw recording I made of this....

<a href="">ProtosynthRAW by concretedog</a>

or if you want to hear it sounding a bit more interesting this is me playing it through the trusty old Zoom PFX9003 fx unit, lots of low end on this one so headphones are recommended

<a href="">Protosynth9003 by concretedog</a>

In a massively off topic finish to this post I took a photo of a dragonfly yesterday that I'm really pleased with and have to share!(click to view larger version)

Tuesday, 8 June 2010


Getting back into a bit of low end synth diy...I gave a friend the synth that I used to record "blackbox" (listen here) off my ep he was so pleased with it, it's inspired me to try and build some more stuff...I want to build not just a load of mixed oscillators but some kind of ghetto sequencer as examples as yet but stay tuned!

Above is the synth I gave to my friend being put through it's paces much to other party guests amusement!

I'm building stuff using the popular CMOS range of logic chips using info from the following excellent pages....they're pretty easy to work with and give pleasing whirs, blips and glitches with minimum cost.