Congrats to everyone who got their Fred working... a world with more Freds is a better world. If you spent time finishing him off, mounting in a case etc., please bring him with you for everyone to see. If you ran into problems, bring him back and I'll see if I can do some troubleshooting. True fact, tho, is that sometimes a circuit-bent project just doesn't work... chips blow, or the magic smoke comes out. Sometimes it's just time to move on.
Besides more practice w/ the mechanics of making, the idea of changing the resistor/capacitor combination to change the speed of the circuit is something we'll be using a lot. More schematic practice comin your way soon, too.
Coming up this week: amplifiers. The oscillators we'll be building won't drive a speaker directly, so we'll need something to amplify them with. You’ll need your speaker, and fresh 9v batteries (the Victorian Synth project is pretty tuff on batteries; pick up 2 if you can so you have a spare). If you've got a kit bring it, it has almost all the parts you’ll need. Still waiting on some components, but if I don't have kits for everyone by Sat. I'll have components so you can build the amp.
Folks have been asking about tools, I'll try and post a list of recommendations in a couple days. Got a couple other questions that I thought I'd post:
Q-- I connected [Fred’s] speaker wires to a line out (1/4 inch output jack) and it doesn't work with my guitar amp, all I get is static coming trough the speaker. I plug it into my small "Smokie" amp (powered by a 9 volt batter, small speaker) and it play but with slight static. If I clip it to a speaker, hey! No problem there! What's the cause of this? Any ideas? Do I need a pre-amp?
A-- fred puts out a speaker-level signal... which means that it's hotter than line level, and often will overdrive/distort if you connect to an amp.
we’ll do something with voltage dividers sometimes soon. [update: see Voltage Dividers] in the meantime radio shack used to carry a cable for connecting the headphone out of a walkman to the line in of an amp... if you could find something like that it might help. [followup: it did]
Q-- ...I saw you troubleshooting that fred board while we were wrapping up. What were you doing? I have a bunch of non-working guitar pedals... Do pedals typically "break" because of loose solder joints? How do I check connections?
A-- a lot of basic trouble shooting is checking continuity of connections... making sure things that should be connected are, and that things that shouldn't be aren't. i was probably using the continuity checker on my voltmeter... basically it just beeps whenever the probes are connected together. sometimes solder joints look good, but you check 'em and they're not... othertimes, a little blob of solder has made a bridge between what you just soldered and some adjacent component.
pedals often go out due to broken connections or controls... the battery connection in particular, since it gets yanked on; likewise the switch since it gets stomped. so those are good places to start checking.
a cheap voltmeter is pretty handy, i use that continuity test all the time. i’ll go over the basics of how to use one in a future install.
Thursday, June 26, 2008
Thursday, June 19, 2008
Week 2: Fred
I had a little trouble getting enuf piezo pickups to make contact mikes, so this week we'll be working on Freds:
This will be about as close as we get to "circuit bending", you'll get some experience soldering/desoldering circuit boards plus an intro to various kinds of resistors, some discuss about playing interfaces... plus a Fred to call your own.
Here's the instruction sheet [posted as webpage 7/14]; see you Saturday.
This will be about as close as we get to "circuit bending", you'll get some experience soldering/desoldering circuit boards plus an intro to various kinds of resistors, some discuss about playing interfaces... plus a Fred to call your own.
Here's the instruction sheet [posted as webpage 7/14]; see you Saturday.
Tuesday, June 17, 2008
Monday, June 16, 2008
Week 1 recap
Great initial meeting, thanks to all for your patience and participation! We got thru some initial soldering practice (making up some test clips that we'll use for the rest of the sessions), and the Victorian Synth project.
Soldering: everyone seemed to get the hang of things right away. The basics again:
Victorian Synth: Again, everyone seemed to get it... I'll try and post the recording later this week. masami akita is jealous already
Schematics: I also wanted to post the intro to schematics that I scrawled out on the pad. As said, schematics are the road maps that represent electrical circuits, and one of our goals is to get everyone familiar w/ schematic basics so you can build designs you find in books or on the net. Here are the symbols used for our first project:
Every electronics component has its own symbol; and then lines between them that represent the wires connection them together.
In this project, the "switch" was the bits of foil we put in the speaker cone--when they touch, they close the circuit and conduct electricity; when they jump apart (as a result of the speaker spazzing out) they open and stop conduction... so the schemo for the first version looks like this:
That dotted line represents the mechanical connection between the speaker and the switch, and that's what creates the "feedback loop" where the speaker turns itself an and off to produce sound. the tone (or pitch, how fast the speaker cycles on/off) is determined by that mechanical connection...
When we complicated that w/ the 2-speaker version, we just took 2 synths and connected them together. in this case, we connected the switches and speakers in series (meaning one after the other)... in that configuration, both switches needed to close (foil in both speakers touching/conducting) in order for the circuit to be closed and the speakers to jerk.
As simple as that is, it's how most projects work... taking smaller building-block circuits and connecting 'em together to make something more complicated.
Anyway, here's a couple more symbols we'll use next week:
See you Saturday!
Soldering: everyone seemed to get the hang of things right away. The basics again:
- use a small (25-40 watt) soldering iron designed for electronics
- use small-diameter rosin-core "60/40" solder, not acid core.
- keep your soldering iron tip clean by wiping on a damp cloth or sponge
- make sure the wires/components are clean--no corrosion, insulation, oil etc.
- heat the joint and apply the solder to the hot wires, not the iron
- apply enough heat so the solder "flows" into the joint; avoid cold solder joints where the solder just forms a little ball sitting on top of the joint
Victorian Synth: Again, everyone seemed to get it... I'll try and post the recording later this week. masami akita is jealous already
Schematics: I also wanted to post the intro to schematics that I scrawled out on the pad. As said, schematics are the road maps that represent electrical circuits, and one of our goals is to get everyone familiar w/ schematic basics so you can build designs you find in books or on the net. Here are the symbols used for our first project:
Every electronics component has its own symbol; and then lines between them that represent the wires connection them together.
In this project, the "switch" was the bits of foil we put in the speaker cone--when they touch, they close the circuit and conduct electricity; when they jump apart (as a result of the speaker spazzing out) they open and stop conduction... so the schemo for the first version looks like this:
That dotted line represents the mechanical connection between the speaker and the switch, and that's what creates the "feedback loop" where the speaker turns itself an and off to produce sound. the tone (or pitch, how fast the speaker cycles on/off) is determined by that mechanical connection...
When we complicated that w/ the 2-speaker version, we just took 2 synths and connected them together. in this case, we connected the switches and speakers in series (meaning one after the other)... in that configuration, both switches needed to close (foil in both speakers touching/conducting) in order for the circuit to be closed and the speakers to jerk.
As simple as that is, it's how most projects work... taking smaller building-block circuits and connecting 'em together to make something more complicated.
Anyway, here's a couple more symbols we'll use next week:
See you Saturday!
Week 1 plan [frm the archive]
Our first get together will be this Saturday, 6/14; at Visible Voices bookstore 1023 Kenilworth in Tremont. huge thanks to Dave Ferrante for providing space for this. 1:00-3:00 PM, we will start on time, really. gonna be fun.
we have 18 folks signed up, which is a few more than i'd originally planned on. we'll see how it goes, if it seems unmanageable i'll figure something else out. glad to have folks w/ a variety of backgrounds and experience. . . those of you w/ some projects under your belt, be prepared to pitch in w/ "teaching".
i'm planning on 2 very simple projects for this week: the Victorian synth from the Collins book, and a contact mike. YOU WILL NEED TO BRING A COUPLE THINGS:
- a 9v battery
- a small speaker (naked, 2 to 8 inches across). . . pry one out of a dead boombox, or from radioshack or RAM electronics (1898 W 25th St)
- a handful of small bare metal objects: beercan tabs, hardware bits, paper clips, foil. . .
- a buck for misc. bits, PLUS either a guitar patch cord to cut up, or a couple bucks for some connectors
TOOLS: i will have some tools to share, but w/ this many people it wd slow us down to all be waiting on one or 2 soldering irons. . . so if you have any of the following tools, plz bring them:
- small soldering iron
- wire cutters
- wire strippers
- needle-nose pliers
i will also have some initial parts kits for sale for $25. i have about a dozen kits made up, and will order more once i know for sure how many we'll need.
as mentioned, i'll be referring to Nic Collins book "Handmade Electronic Music: The Art of Hardware Hacking" as a reference/textbook. you do not have to own a copy, but if yr into this kind of thing it's pretty great, you could spend a few months just working through all his projects. contact Visible Voices if you want to pick one up.
email me if you have any questions, see you on Saturday!
Proposal [frm the archive]
i am considering setting up an ongoing series of "classes" on diy electronics for music and noize. these would be hands-on sessions, meeting once a week, with simple projects and opportunities for collaboration. possible topics/projects might include:
the "textbook" would be Nic Collins Handmade Electronic Music: The Art of Hardware Hacking. there would be materials costs involved, around $25 for a basic kit of components. no previous electronics knowledge necessary, but some creative background (not necessarily musical) would be helpful.
If you might be interested in something like this, please send me an email (fluxmonk @ gmail dot com) with the following info:
- vibrations & AC (oscilloscope visualation)
- transducers (contact mikes, pickups, speakers)
- amplifiers
- feedback systems (electronic, mechanical)
- schematics & breadboards
- basic oscillator (CMOS)
- multiple oscillators
- intermodulation, static mixing
- user interfaces: gesture & performance
- mixers
- more oscillators, dividers
- sequencers
- recycled enclosures
- performance proof vs. decay as growth... impermanence
the "textbook" would be Nic Collins Handmade Electronic Music: The Art of Hardware Hacking. there would be materials costs involved, around $25 for a basic kit of components. no previous electronics knowledge necessary, but some creative background (not necessarily musical) would be helpful.
If you might be interested in something like this, please send me an email (fluxmonk @ gmail dot com) with the following info:
- preferred days/times
- any previous background w/ building stuff
- any previous background w/ playing stuff
- any goals, thinks you'd like to get out of this
- waffle preference: crispy or soggy?
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