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Synth In a Box

I have been conducting a series of music electronics workshops in conjunction with Switched On, the awesome Austin synthesizer shop. In the November 2011 workshop we build a new mini synthesizer that I designed.


It is a simple CMOS synth, but it has a lot of features:

  • Two audio oscillators
  • Two LFOs – one per oscillator
  • Pseudo ring modulator effect – the classic CD4011 XNOR circuit
  • Attack/decay volume envelope – the even more classic single transistor VCA
  • Master volume control and separate volume controls for each oscillator and the ring mod
  • Five passive low pass filters for wave shaping of the LFOs, oscillators and ring mod
  • Three modes: constant sound, gated (using the pushbutton) or repeated
  • Repeat circuit with separate controls for on time and off time
  • Built in amplifier and speaker as well as 1/4" output jack

The cardboard box enclosure is a bit of fun. One of the best parts of DIY synth is building the enclosure. I have seen, and built, all sorts of enclosures, but I think this might be the first synth built into the box that the parts come in.

I actually had eight kits leftover from the workshop, but they're all gone now.  If you want to build one yourself, just follow the diagrams below. Given that the preceding sentence constitutes the complete build instructions, I would consider this at least an intermediate level project. Of course, if you do want to build one and have any questions, feel free to contact me. I am always happy to help. The below diagrams are also available in this PDF file, which also includes the bill of materials. Oh, and you can use any enclosure - it doesn't have to be cardboard!



Synth In a Box Sample Sounds by Delptronics

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EEWeb Interview

I am the EEWeb featured engineer of the week!  When they asked to interview me, I was a little reticent because all I do is make weird noises and their usual featured engineers are working with NASA or building neural imagers (actual rocket scientists and brain surgeons). Then I figured, hey, it's all electronics!
Check out the interview.

chipKIT Uno32 Road Test

Electronic components distributor Newark recently asked me to road test the chipKIT Uno32, a 32-bit Arduino UNO compatible development board based on the Microchip PIC32MX320F128H Microcontroller.


chipKIT Uno32

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Birdianoforte: Circuit-bent Bird Song Calendar II

I took another run at bending a bird song calendar. I wanted to do something more complex with it than I did the first time . I had planned to enter it in the Second Annual Moog Circuit Bending Challenge, but alas, I did not finish it in time. Oh, well, there’s always next year, and in the meantime, I have this cool bird piano – the Birdianoforte!

The stock functionality of the bird calendar is quite simple – just press a button to hear a bird sound. The Birdianoforte is quite a bit more complex, and far more playable as a musical instrument.



Read more: Birdianoforte: Circuit-bent Bird Song Calendar II

Custom Ring Modulators

In addition to the standard kit, effect box and Eurorack module versions of the Ring Modulator, sometimes I am asked to create a customized version for a customer.

If you are interested in a customized version of a MickeyDelp.com/Delptronics product, or even a completely custom built device, just contact me and we'll discuss it.

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EEweb Site of the Day

MickeyDelp.com is today's EEweb Site of the Day!

Microstick Road Test

Electronic components distributor Newark recently sent me a Microchip Microstick to road test. The Microstick is a tiny $25 development board for getting started with Microchip's 16-bit microcontroller families.


Microchip Microstick Top View
Microstick Top View


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