My friend Larry referred me to this great idea on Instructables from user Rosenberger31… a DIY usb power outlet for your car. There’s no need to repeat the details here as Instructables stands alone as one of the best DIY sites out there. I will say this though, I’d love to see this in a Lotus Exige S 260 instead of a Prius.
A USB power outlet on it’s own may not make music but it will make it a lot easier to hook up a few of these and pipe them into your auxilary in.
I don’t know much about this one except what is written on Matrixsynth
This one in via John L. Rice. It’s a Living VCO made by Peter:
“I’m not a MOTMer & I make my own panels, so I don’t have much to add to this debate. I did however finish wiring my Living VCO module today. Its still on the bench being checked over and is not integrated into my system yet but is looking and sounding good so far.
I managed a FRAC format panel design that has all the stock features and fits pretty comfortably (for me) on a 5U frac panel.
Here’s a pic of the module taken some time ago before beginning wiring.
peter”
You can get the original post here:
http://matrixsynth.blogspot.com/2010/05/living-vco-diy-module.html
The title says it all. This is way past old news but it’s still a gem. This photo comes by way of Flickr but it was taken at the first (as in 2007) “handmade music” event at Etsy Labs in Brooklyn NY, sponsored by Etsy.com, MAKE Magazine, and Create Digital Music.
In the world of hacked and modified sewing machines using arduino to control max msp and generate music Lara Grant owns it big time.
From her Flickr page:
Lara Grant, part of the circuit bending orchestra for Diana Eng’s Fairytale Fashion Show held at Eyebeam NYC. Through various hacks and circuit bending techniques, Lara’s sewing machine trigger signals that is then fed onto laptops running MAX/MSP to produce the final soundtrack for the runway. Other team members of the orchestra are Peter Kirn and Matt Ganucheau.
You can see the project blog here:
http://laras-home.com/itpBlog/2010/02/16th-and-mission-p-s-1-version/
Which has many more great closeups like this one…
and more of her and her sister’s work here:
I frequently work on projects in the living room in front of the TV while sitting on the couch soldering away hunched over a disarray of wires, parts, wires, speakers, cords, breadboards, and tools. Whenever I want to work from the couch I have to go into the studio and make 15 trips up and down the stairs, cables, toolbox, parts boxes, soldering iron, etc. It’s always a major hassle. Then, when I’ve finally completed mocking something up on the breadboard and I want to test it I need speakers, headphones, a sound source and I have to connect it all with alligator clips. It’s really inefficient and makes me less apt to start a project because all I can think about is the huge mess it’s going to make.
So I decided to put everything I need into one self contained box; an audio test and development box. Below is a description of the parts and procedure I used to put it together. If you’re in a similar situation hopefully this will give you some inspiration to come up with a solution that works for you.
If you want to see all the project photos in high resolution you can find them on Flickr here: Audio Test Box Images
Initially I needed to build a box. I looked through all my scrap wood and it was all ¾” plywood which would be way to heavy. The smaller pieces were odd shaped and unusable. I looked at everything from cookie tins to shoeboxes and didn’t like anything I was coming up with. I checked Wal-Mart for something I could get cheap and hack into what I needed but I didn’t find anything there. Then I went to Hobby Lobby because I remembered they had some project boxes for putting flower displays in. After looking through the whole store though I found the perfect box. It’s a miniature “child’s desk” with a top that lifts up. It was exactly what I was looking for, I just didn’t know it. Best of all, it was only $15. You can find them here: Wooden Child’s Lap Desk
What I wanted was a box which had a variable DC power supply, an AC jack, an amplifier, speakers, an audio source, an AC outlet for the soldering iron, a place to put some tools or parts, a quick way to hook up audio ins/outs and DC voltage, and room for multiple breadboards.
Most of it I was able to find around the house. Here are the guts from a pair of old busted up (but functional) computer speakers. These had been lying around for years. But even if I didn’t have them I see them all the time at Goodwill for a couple of bucks. It was a bit of a pain to crack these open. Most of them are manufactured so you can’t service them so you have to break the seal on the plastic to get to the guts. I just used a screwdriver and pried the crap out of it until it snapped. Dirty but easy.
The DC power supply I used was one I had purchased a couple of years ago for a project. It’s a Meanwell Switching Power Supply that I picked up at Fry’s. Fry’s is one of the last few national stores that still carry electronic components. It’s convenient if you need something right away… just hop in the car and get what you need… but be prepared to pay a premium. Anyway, this is the power supply: Meanwell Switching DC power Supply I’ve used this power supply dozens of times and it’s great. AC in, DC V+ and V- out with a neutral earth ground. The voltage is adjustable from 10 to 15V DC which covers just about anything I’ll ever do.
Skipping ahead, I started drilling and cutting openings for the parts. Depending on what you’re using for parts and a box you might have to do something different but this worked well for what I was doing. The two speakers in the bac and the AC cord jack on the front right corner so I could comfortably plug it in. I used two tools to cut the holes. The circles were cut with a Dremel tool and the rectangular hole I used a chisel. The wood on this Hobby Lobby box was really soft so chiseling out a hole only took about 10 minutes. One word on chisels… never use them for anything other than wood, store them safely, and keep them oiled. Nothing worse than a fucked up chisel.
The speakers fit perfectly in the back corners of the box. I really couldn’t have built something better than what I bought at Hobby Lobby. And like I said, the wood was really soft so I was able to screw in the speakers directly into the wood using the screws used in the original plastic enclosure. This was much easier than sifting through bins of spare parts finding something to fit. Screwing in the AC jack was equally simple.
Next I installed the amplifier section of the computer speakers. I wanted to use the original DC power supply that came with the speakers so I wasn’t running it off of the supply I’d be using for a project. I simply screwed in the transformer directly into the wood. Now, this probably isn’t the safest way to go about this. The wires are exposed, and there’s no heat sink so do this at your own risk. Next I needed to attach the amplifier to the box. I didn’t have any standoffs that were the right size and the mounting holes were in awkward positions. I decided to make my own brackets. I frequently make brackets for projects using ½” brass strips. You can find these at pretty much any art supply store or train/model hobby store. They’re cheap, really strong, easy to bend, and easy to cut with a Dremel. A couple cuts, bends, and holes drilled and I was set up. I used mounting screws and nuts to adjust the height and stabilize the front of the circuit board
So when soldering it’s important to keep a wet sponge near by to occasionally wipe the tip. I made my own little portable holder that I’ve used for years now. I love Pillsbury’s Flaky Supreme cinnamon buns. When you’re done baking them you slather on that super sugary frosting and they’re delicious. I keep the plastic containers that the frosting comes in and wash it out, cut two plain old sponges in circles and plop them in the plastic container. Add water. It’s just the right size and stays wet for a day or so. Only problem is that it slips and slides all over the place which can be a hassle.
So, to keep the sponge from sliding all over the place and keep it at arms length I chiseled out a circular depression in the top of the box which the plastic container can rest in. Again, the wood is soft on these boxes so it didn’t take long at all. Just took a little patience so that I didn’t slip and chisel out a huge piece of wood.
Next I wanted a built in outlet for my soldering iron so I didn’t need to keep an extra power strip handy just to use one outlet. I went to home depot and bought a wall jack with only one outlet. In this instance I bought a safety outlet. I figured since I’m mounting the outlet directly to wood, with no switch, or fuse the least I could do is get a safety outlet. I’d suggest putting in a power switch and fuse if you try this. Chiseling out this hole took a bit longer and the wood needed to be notched out so the outlet would sit correctly. Also, because of limited space on the side panel I had to trim off the ends of the mounting brackets (not shown in this picture). The Dremel saves the day again.
Skipping ahead, here’s the AC wired up. I stripped out the heavy gauge wire from an old busted power strip and trimmed it to size. I added some heat shrink tube for color coding. The wires on the end of the AC input jack needed to be soldered but on the other ends I crimped on some spade tongues so I could connect/disconnect the wires quickly and easily if needed. I did this for all the AC lines. The wiring is pretty simple. White and black or the power inputs and the center is ground. I go from the input to the outlet to the power supply. Not visible in this picture is the AC power going to the amplifier in a similar fashion.
I had to drill a number of holes on the lid of the box so I could mount binding posts, switches, and jacks. Because the wood was ½” thick I needed a small hole on one side and a large hole on the other to fit the body of the component. Drilling the small hole is easy. Just choose the size that matches the width of the threaded mount on the component. To make a larger hole that sinks in to the correct depth I use an old trick. Measure the depth you need up the drill bit from the tip and then wrap a bunch of masking tape around the drill. Now drill your larger hole over the smaller hole and only go as deep as the tape. I tend to add a lot of tape so in case I push to hard the tape actually stops the drill so I don’t go all the way through the wood and ruin the hole.
Here I mounted three binding posts across the top of the box for DC power. I simply drill holes and screwed the plastic posts into the holes. The wood is soft so they took really well. I did have to tweak the size a bit with a round wood file but that was minimal. Because you can’t get in under the top of the box it’s necessary to solder the connection wire to the bottom of the binding post before you screw it in. I made sure to use heat shrink given the proximity to the DC & AC power wires.
Here are all the binding posts jacks, and switches installed followed by an image of the underside of the lid. All jacks were wrapped in heat shrink tubing. I tidied up the wire using staples from a staple gun. Instead of using the staple gun though I gently pushed the staples in with needle nose pliers so as not to knick the wires. After I had put this all together and tested it I was having a hell of a time getting the audio out to work right. The wiring wasn’t at all complicated so I had no idea what was wrong. I should have known though… one of my switches I bought at Radio Shack. So besides being completely ripped off by having to pay $3.99 for a $0.20 switch, I also got totally hosed because their parts are worthless shit.
These last two are the finished box (for now). You can clearly see I can fit around four or five breadboards vertically on the top of the lid if need be and all my ins and outs are in easy reach. The lid opens up and provides enough extra space to keep the AC power cable, a soldering iron, the sponges, some solder, needle nose, a pencil, or whatever. On the second picture if you look inside you’ll see a little RCA .mp3 player. I bought this at Wal-Mart for 30 bucks. It’s 2GB mp3 player/flash drive that runs on 1AAA battery. What I’ve done is load up 25 clips of various types of instruments or sounds. Guitars, vocals, drums, bass, synths, full songs, etc. This way when I’m testing an audio circuit I’m working on I can listen to how instrumentation actually sounds running through it. And when I’m done I can grab it and go. I used to have an iPod and lost it… which I was OK with because iTunes irritated the crap out of me. This thing was super cheap, has plenty of storage for what I need, and all you need to do to add .mp3s is drag and drop.
And last but not least, here’s a poorly drawn diagram of the entire operation. I’ve set it up so that either an internal or external audio source can feed the development circuit via the internal .mp3 player or an auxiliary stereo ¼” jack. Just connect the input binding posts to the circuit you’re working on (left, right, gnd). If your not working on a stereo set up I’ve added a mono/stereo switch which merges left and right and sends it to the ‘left’ binding post. Second you can easily hear the impact your circuit has on audio I’ve added a bypass switch so you can toggle between your circuit and direct audio out. Third, when the audio exits your development circuit it feeds into the binding posts on the right which subsequently feed the internal amplifier and speakers. Should you prefer to send the signal out to an external amp (or whatever) you can do so via a second stereo ¼” output jack. If the signal from your development circuit is mono, there is a stereo mono switch that sends the mono signal (connected at the L binding post) and feeds it to both the L & R inputs of the internal amplifier. I’ve tried to draw it out so it makes more sense than I’ve written it here. Of course, if you have questions just leave a comment or email me.
I remember I though this thing was so rad when I first bought it back in 97-98ish. These days it pretty much collects dust except for the occasional use of its arpeggiator. Nonetheless I thought it would still benefit from some blue LEDs under the keys. What can’t be seen is the addition of two Burr Brown OPA132 Op Amps to the output section. They won’t do much for the timbre of the lousy PCM samples but they do make the outputs sound brilliantly crisp.
Back in 1997 a company called Music and More (MAM) created a tb303 clone called the MB33. They licensed their design to another company called Freeform Analogue Technologies who dubbed the same clone the Freebass FB383. I guess it’s a clone of a clone? Both were identical and affordable during a time techno was all the rage and everybody and their brother HAD to have a tb303. Despite the overused sound and the long past death of techno these little boxes still have a good deal to offer…. Especially at current prices…. Originally around $400… I picked mine up for $10.00 on eBay, albeit broken. Due to poor manufacturing many of these guys are broken these days and don’t produce any sound however, you can still tap into their analogue resonance filter to add some nice tone to just about any instrument and add a excellent tool to your studio. The mods that follow show you how… and it will cost you pennies.
Assuming you’re familiar with the FB383/MB33 you’ll know there is an external input on the back to patch a signal through the filter section of the unit. Assuming your unit works you know that when you connect a signal the internal synth is disabled which makes racking the unit a major hassle. By adding a filter on/off switch you can keep your unit racked and patched to a patch bay and use the filter easily. If your FB383/MB33 doesn’t work, like mine, then it’s basically a signal on/off switch. I plan on making a cv input for the oscilator and when i do, this mod will still be neceassry if i want to rack the unit.
The photo above is a shot of the finished mod. You can see more details, photos, and descriptions at the link below.
The Full Flickr photo set here.
As with most external filter units, you need to trigger the envelope section before you will hear any sound. So if you have an input signal patched and the envelope is not triggered you hear nothing. To do this you have to supply a voltage to the bias input of the Operational Transconductance Amplifier (OTA). Instead of applying a direct voltage I opted to use a pot to drop the voltage at the base of a transistor controlling flow to the bias input… drop the voltage and current flows to the bias input. With higher voltages you get some gritty distortion which isn’t so bad in some cases. I soldered one lead of the pot to ground and one to an easy to reach lead on the end of a 0 Ohm resistor. That’s what you see in the photo above.
As before, you can see the full set of photos by the link below.
The Full Flickr photo set here.
This one is pretty self explanatory. There is a resistor in place that restricts the resonance a bit. By bridging this resistor you can get some nice thick resonance and even some self-oscillation. Instead of simply bridging it though I added a switch to allow for ‘normal’ and ‘boost’ modes for a variety of applications.
As with the previous mods… photos and details by the link below.
The Full Flickr photo set here.
When initially looking into information on the FB383 I immediately figured out that nobody has any. Nobody. There was virtually no information available on the net with the exception of a brief background on MatrixSynth and some information on possible mods (for a fee) at Circuitbenders.uk. Of course there were reviews at typical locations like hyperreal and harmony central but other than that it was limited. I managed to track down someone familiar with MAM products through the company that ate them, Musonik, and figuring that somewhere someone would have service manuals, design specs, part sources, etc. I was wrong. Nothing.
So given the good number of these machines out there and the likelihood that there were a fair number of folks in need of a signal flow diagram I made a high resolution circuit overlay of the Freebass FB383 (MAM MB33). It’s not a schematic but it’s about as close as you can get. I’ve found it immensely useful and have it available here for any and all to put to good use. Enjoy!