that is way cool. Im also an Ableton fan and plan to use my apc in the same way once I figure out how to make it! Im kind of an electronics dummy, Ive mostly only bent speak and spells and casiotones but Im ready to try a project like the apc. My stupid questionis are .... 1) I have found several diagrams for the apc like the one at the link you posted using stripbaord. I found some stripboard like thing at Rat Shack, but it doesnt have solid long copper strips, more like each whole surrounded by a copper ring. 2) Im not sure how things actually have to be wired (or if) together once on the the back of the board...) Hard to tell from the youtube vid, but it looks like your tupperware apc is on a breadboard? Any advice for the newbie would be appriciated. thanks!!
It's better to get strip board (strips of copper wire) otherwise you'll have to make connections with wire. when you drill to break the tracks go over it with an old toothbrush and check with a multimeter that the track is really broken (also diagonal, etc.) It's REALLY easy to have a tiny piece of copper shorting it.
Strip board is a pain, but this is such a tiny project and i reckon it's good practice before you do something "real" with a PCB. If you can bend a Speak & Spell you can build an APC.
Regarding the veroboard version of the APC; I dot the components and the veroboard. The only thing I dont understand is there the wire going from the 9V battery crosses and seems to connect(?) with the wire coming from the 500k pot. Does that mean that both wires are supposed to connect on the same place on the veroboard? Just call me newbie.
Don't know if anyone here can help me with this? I've built two different APC circuits this weekend. One with a 556 IC and another with dual 555 ICs. They both work but they both have the exact same problem, the volume is very very low. Bypassing the 10k resistor before the output makes it very loud so I could swap this out for a lower value resistor to make it work. However, that won't help me understand what's gone wrong. I've checked both circuits for shorts and bad wires etc. Can't see anything wrong. I've also triple checked all my resistors and caps are the correct values. Is there any chance that the IC chips might behave differently due to manufacturers making them slightly differently? I'm a bit stumped to say the least.
This is a related/piggyback question: I'm planning on building a few of these into some old home stereo speakers (unpowered) but I can't seem to find any info on what size speaker they can drive without additional amping. All the articles say "small 8 ohm speaker." 8 ohm speakers are everywhere in every size and I know nothing about impedance etc.
Maybe the speaker size has something to do with your volume problem?
I have tried a few different speakers and also have had it running out to a jack socket and hooked up to a mixer - no different. A friend of mine is having the exact same problem with low output volume. Turns out we are both using ST branded NE556N ICs so we're wondering if this is the cause of our combined woes. I'm gonna try and get some different chips and have another go. We've both built about 3 APC's each with the ST chips this weekend, all with the same problem!
The 10k resistor is for a line out otherwise the signal would be too hot. The original schematic was meant to drive a small speaker probably without the resistor. But you already got that!
Get the "Handmade Electronics" book, there's a whole section about cobbliing Schmitt trigger IC's together for similar pulse wave mayhem but more complex modulation. Haven't tried it yet but it sounds like fun & really simple too.
« Last Edit: August 24, 2008, 10:29:38 PM by djsynchro »
Not only is the stuff in the Nicholas Collins book very accessible and fun, it's also a fantastic way to learn some basics of what actually does what. After a couple of weekends breadboarding some of the projects in that book and experimenting with different components I learned more about how a sound circuit goes together than months of reading on the internet.
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I'm planning on building a few of these into some old home stereo speakers (unpowered) but I can't seem to find any info on what size speaker they can drive without additional amping. All the articles say "small 8 ohm speaker." 8 ohm speakers are everywhere in every size and I know nothing about impedance etc.