Cavan Fyans at the time of writing this is a PhD student at the Sonic Arts Research Centre. His personal site along with detailing his extensive academic work also outlines a number of his DIY electronic instruments. My favorite is the “Tape Box 2” which as the name suggests is an updated version of “Tape Box 1″. It’s perfectly simple, does what it should, and doesn’t distract with excessive controls, knobs, and gimmickry. I also have to give him a thumbs-up on his use of high quality pictures documenting his work online. Nothing makes me more disappointed than a thumbnail that leads to a picture of… a thumbnail.
This is from another ElectroMusic.com user named ‘RF’. ‘RF’ [Nick] has built a monster DIY analog synth built mostly from MFOS kits from Ray Wilson. RF’s site gives a great deal of information on where he got started when looking to explore DIY synthesis. One of these days I’m going to take off 5 years and photograph all of these synths and publish it in a luxurious hard cover volume with nothing but gear-porn quality photos.
DroneGoat is a tasty little blogspot blog covering analog synthesis and some DIY projects (among other things). There’s lots of great stuff here but I found this to be particularly awesome. An analog ring modulator built into a Brain water bottle. Reminds me of my Alpo-Can ring modulator except this appears to process inputs and not simply modulate internally generated square waves.
Flickr user Equaliser (Steve Woodward) has a nice pic of his DIY Polivoks style filter posted. The kit is available through Papareil Synth Labs and on their site you’ll find some good historical information and documentation of its workings. Here’s a shot of the schematic (click for link to original .pdf).
Steve has some great audio clips of the filter in full effect here
Jürgen Haible from Germany redesigned the Tau Pipe flanger and documented the test and build in great detail at his site http://www.jhaible.de.
His site has more information than you could ask for when it comes to synth and audio effects DIY. He includes schematics, block diagrams, design and test notes, high resolution pictures, mp3s, external links to resources, formula calculators, spreadsheets, etc. He does this for over 25 projects. It’s truly impressive. Take a look at the images of his Tau Flanger/Phaser redesign…
I happened across Ryan’s excellent DIY synth and immediately recognized the housing he used for it. It’s a Victoreen Radiological Survey meter. You can find these in abundance on eBay for pretty cheap (which is exactly what I did). Hats off to Ryan on this really cool modification. You can find images and more about Ryan on his site Pickleinn.com
Rare Beasts is out of Australia and they make a small unique selection of great handmade effects-processors/audio noise machines. Definitely take a look at their custom gear at their Etsy shop. The most recent release is a great little sampler/looper/noise generator called The Wicks Looper – Acid Mix.
From Rare Beasts’ Etsy site:
The Wicks Looper has 3 main controls; The frequency control adjusts the frequency of the noise, the first half of the range is tame, the 2nd half is uncut noise. The second control is Speed, which controls how fast the loop is played. The right hand side of this control plays the loop, forwards, turn the control to the left and the loop will play in reverse. Write the loop at a slow tempo then speed it up and reverse it, for a great effect. The third control is the write button, when pressed it writes a sound to memory which is then replayed next time the loop is run. With the Freq control knob adjusted anticlockwise, you can add a rest to the loop by pressing the Write button.
The video says it all… simple and cool.
This is a ‘ring modulator’ similar to the one used in an ARP Odyssey… this version operates by the input of two square waves into a 4011 quad NAND gate. I didn’t have a 4011 available so in this version I use a 4001 quad 2-input NOR with two inputs wired to ground (low) instead of wiring the 4011 with two inputs wired to Vcc. If I did my logic correctly the 4001 works the same when wired this way. I included the logic tables on the schematic.
The two square wave tones passing into the gates are compliments of a simple op-amp square wave generator circuit. Information on how to wire one of these up is widely available on the web. Here’s one good resource. The original schematic and idea was found on simple-answer.com here. A brief reference to the ARP Odyssey and this ring modulator is mentioned on Wiki here.
Obviously this is in an Alpo Can. The circuit board can be viewed on Flickr (see link below) but it was pretty small so it had no trouble squeezing in there. The knobs were found on eBay for dirt cheap. The hardest part about modifying this can was getting the sharp edges off the holes drilled into the can. To get the top off without cracking open the dog food… and to be able to take the top on and off the can you’ll need one of these: Kuhn Rikon Safety Lid Lifter
More photos and comments can be found on Flickr here:
4001 Ring Modulator in an Alpo Can
Sound Samples:
This is a Ring Modulator or similar sounding effect box based around the AD633 (Analog Devices Four Quadrant Analog Multiplier). The original design is taken from Roman Sowa. His website has further details on his design and the schematic I used as a starting point. The above photo shows the finished version albeit without knobs. This is mostly because I, despite better judgment, bought pots from Radio Shack, and didn’t want to waste them. As you can see the shafts are just a bit long. No matter; they work.
I made a few modifications. The first was to remove the option to select AC/DC coupling. I felt that I had no need for DC coupling so I hard wired it up AC coupled. Secondly I added some gain on the clean channel. The clean signal was coming through a little light which I personally didn’t like. Lastly, I added a LED meter on the output volume which you can see in this picture. Using a LB1403N I made a level meter which increases as you turn the volume up. This doesn’t actually monitor signal level but the position of the pot. There’s no real purpose other than I like blinking, flashing, pulsating and adjustable lights on all my gear. Who doesn’t? It’s wired through a dual ganged pot with a trim pot to adjust sensitivity. The detailed photos can be seen at the full Flickr photo set.
From a distance the paint job looks OK but as you can see in the first photo there’s definite room for improvement. Wet sanding, Clear Coat, and Polish would definitely help but it’s not a bad first run. The fluorescent paint however had a tendency to get ‘powerdery’ and presented some problems. Check the sound samples below to hear what it sounds like.
Many more photos and comments on the build can be found on Flickr here:
AD633 Ring Modulator
Sound Samples:
Before & After Number 1
Before & After Number 2
Before & After Number 3
Before & After Number 4
