My first DIY synth

[Timodon]

Here's another plug for Nic Collins book.... if you're into circuit bending and have wondered about but never tried Synth DIY buy it, skip straight to chapter 18 and never look back. I designed and built this entirely myself after swallowing the whole book.

DigiBeta Synth (Hex Schmitt)

It's built into a small DigiBeta case. It has two oscillators, one to play and one to modulate (or not if you switch it off). The buttons can be tuned for melodies or you can let the osc run free and control pitch on the first tuning pot. There are two blendable sounds courtesy of a voltage divider and some diode mixing.

This is still a fairly simple little synth but I did more with it than I would have imagined myself being capable of just a few months ago. The one big hurdle to overcome was transferring from breadboard to circuitboard - once I had learned to assume that I had done a bad job of soldering every joint and made a habit of drawing a point down the grooves between the copper strips to clear out unruly solder that was shorting the whole synth out it all came together pretty quickly and has left me with an appetite for more! Sequencer next? or maybe something a bit more ambitious...

[kitsophrenik]

well done mate.

sounds like a great little box! ill have to try a project like this soon!

[phantompowers]

I know I've already said this several times on this forum but Nic Collins book is an essential information source for anyone who wants to get into electronics, hardware hacking and circuit bending.
Kitsophrenic, you have made a great example of what is possible after ingesting just a few pages of this amazing book.
I'll be making something very similar when I've finished casing and wiring my spring reverb unit. Which incidently was based on information in the same book! Oh, then I've got to bend my DD-5, re-wire my guitar, make another dub siren, finish my modular SK-1, do something with the 6 echo pedals under my desk, (which I'm sure are breeding!) Fuck knows how many keyboards I now own or what I will do with them all, I've then got to repair all my mates broken stuff, bend my voice changer, make another sequencer, and also bend or modify numerous other electronic devices which I'll have undoubtedly acquired during the finalisation of the above!
Last April, 2009, I watched a documentary on Youtube about circuit bending, previous to that I had never even looked at a soldering iron. Since then, with the help of this forum and Nic Collins I have gone manically insane!

[Timodon]

 

[phantompowers]

Sorry Timodon, I meant to mention you not Kitsophrenic!!!

[Timodon]

No probs dude, Kitso's made some good stuff too!

I really am staggered by how cool these CMOS synths can be even when you're just scratching the surface of what's possible with them. After I fried one of my casios    I wasn't sure whether to carry on with the soldering but I'm real glad I did now!

[jamiewoody]

i LOVE this! very cool!

i am curious about the keys...do they come out of on pin on the schmitt trigger (which one), into one cap (which one) then into a series of  trimmers into N/O switches? or is there a different cap for each tone with trimmers for fine tuning?

[Timodon]

Hey Jamie

Thanks man! Nothing that complex I'm afraid! each switch and the associated freq pot (feedback resistor) are hooked up in series between the input and the output of a single Hex-Schmitt oscillator. All three are wired in parallel on the same oscillator which gives you different values for pressing more than one at a time. One cap goes from input to ground, separate from the switches, as per Nic Collins basic oscillator layout.

Our drummer has been using this with a bit of delay at gigs recently to warp peoples minds. The looks on faces are priceless!

[jamiewoody]

again, this thing is awesome! have you ever throught of putting an actual 1 octave keyset under the buttons?

[Timodon]

I'll be honest the amount of stripboard soldering it would take makes me shudder! It's a forest of wires as it is. I could probably be a bit cleverer with that side of it though....

[computer at sea]

Hey Timodon.

If you've got the second edition of the Nic Collins book you should probably build the 4017 sequencer.  It is fantastic and a pretty easy build, all things considered.

[jamiewoody]

so there are 2 editions of this book? is the 2nd edition totally different from the first, or does it just have more pages of projects?

we should start a thread on "reading" if one hasn't been started. i am so behind....i really need to get all the mims mini-notebooks!

even though i have the web at my fingertips, i still love books!

[Timodon]

@Computer at Sea

Yeah It's not that edition although I am planning a sequencer based on a design I found online (plus some changes I will no doubt make when I inevitably wire it up wrong and decide I like the sound it makes). I have the box ready and everything although I'm struggling to find the time to get started. Probably do something over christmas.

Unless I make a stompbox version of my guitar synth fuzz with an optical freq control and maybe a second oscillator mixed with a diode for even more FM-like madness. Or a big fat drone synth with similar chips to the BetaSynth (Hex Schmitt, Voltage Dividers) but using more oscillators and dividers and with a mixer circuit to combine them for a controllable shifting textured wash of noise. That book is too inspiring!

[druzz]

just got my hands on nic collins book from the library . looks very good . i have the feeling i'm about to step in the next level

[phantompowers]

That book is so good. (speaks in a whisper) If you E-mail me nicely I'll send you a digital copy. Shhhh!