Archive for the ‘progress reports’ Category

My Instrument: Process & Conclusion

Monday, December 24th, 2007

By the middle of the semester, I basically realized that I had absolutely no idea as to what I wanted to do for this class. I had a few ideas involving cassette tape, but that area was being explored by roughly 1/4 of the class, so I decided to go back to the drawing board(although I still really want to work with cassette tape loops in the future).

I’ve had this big obsession with synth-drums for the past four years; the image of the stoic, austere Peter Hook rhythmically hitting the Simmons tom on Top of The Pops in 1983 was probably one of the most prominent images I associated with synth-pop of the 1980s(probably my favorite genre of music ever). Additionally, after building revision 3 of my VGA video synth(a synth that I was working on in Ranjit’s other class) earlier in the semester, I still had the idea of doing visuals for class stuck in my head like light-blue fun-tak or something.

I decided to make a video synthesizer, in which Red, Green and Blue VGA output would be generated by a set of logic chip oscillators triggered by drum pads(the construction of which I assumed to be piezo-something, but I <i>still</i> have no idea about piezos–where the heck do you find huge piezo elements?). It was gonna be really cool.

After Thanksgiving, I decided to start working. I previously got a single logic chip oscillator to work, with a little LFO-type thing happening by tying a second chip into the voltage of the first one. I tried really hard to get that to generate video output, but that didn’t end up working. In fact, the chip blew up. Subsequent attempts to get other chips to work failed as well. At one point my breadboard started to smoke!

In a moment of desperation, I turned to my various tiny speech chips. At first, I destroyed my brand-spanking new Soundgin chip by accidentally reversing the pinouts in my head. A few minutes later, however, I successfully set up one of my Speakjet chips, getting it to interface properly with my Arduino. I even got a potentiometer to trigger all 128 different preset sounds(the result was really cool and IDM-y)!

The next challenge was finding a way to make drum pads. My first instinct, the whole piezo thing, just sucked. My second idea was to replicate the technique literally patented by Kraftwerk: to basically create a big button. While one end of the circuit, V+, would be connected to an aluminum drum stick, the other end, the drum pads themselves(also in aluminum) would be connected to Ground with a resistor and an arduino digital input to detect the whole thing. When the Arduino detects the completion of the circuit, the Arduino sends serial out to the Speech chip. After roughly a week of trying to find makeshift drum pads, I found(with Ranjit’s help) perfect pads and sticks at Pearl, which sold nice metal plates and rods. Once I got everything put together, the whole thing worked really nicely(although the speech chip just wouldn’t interrupt any speech playback, resulting in some kinda weird rhythms). The video part was supposed to be next, but then it just sort of fizzled out(mostly because I found out that the performance space didn’t really have any convenient video inputs, and I didn’t really want to destroy my video synth by having it fly across the room). So, I got a nice big piece of soundproof foam and mounted that and I was finished! I went on to practice n’ stuff with Sam and Yelena.

We now have a record deal.

No, not really.

Xing and my robots

Friday, December 21st, 2007

I don’t have too much to add in terms of progress on my instruments Freddy and Teddy.

As you all know, Teddy lost his life on the way to the performance. I was excited to share his sound with everyone. I had recently learned how to loop his sounds and create a few new ones by touching certain points on his board. Unfortunately, I can’t post and samples because he is dead. I do plan on bringing him back to life though, so that is good.

I played Teddy at the performance and it actually worked out better than I had expected. I was worried that our song wouldn’t sound right because we had practiced it all along with Teddy. But, Freddy stepped up to the plate and did a great job. I had a great time performing and wish we could do a few more events…

Here are a few pictures of Xing from the performance. Thanks for a great class. I learned a lot and had a great time. You all made some really cool instruments.

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Xing Raw Live

Friday, November 30th, 2007

We offer you a sneak preview of our upcoming album; Xing Raw Live.

The Whistle and The Robot

RootsNoise

Interlude

SingSaw

Drumpluck

Xing

knapp electrobox01

Wednesday, November 28th, 2007

I set up a flickr set to show build progress.

So far, I have wired the board and done some basic testing with a microchip to sense position. This part is done, now I have to start working out the frequency output and modulation.

Glendon’s Tape-drum machine

Friday, November 16th, 2007

I am building a machine that will be able to play multiple pre-recorded samples from audio tape attached to the outside of a rotating cylinder. In concept this is something like a mellotron which is a keyboard that plays a different tape for each key. On the Mellotron the samples were typically the same sound at a different pitch for each key. My machine will not have a keyboard but instead a tape head that can be slid back and forth to rest on different tape samples. The different samples will probably consist of different pitches but will probably have various sound sources. One note might be a violin, the next a singing voice. Some of the tracks may have beats but these will probably have to be made up of bits of tape arranged in a regularly spaced pattern rather than a prerecorded beat on a continuous tape because the physical length of the beat on the tape would have to exactly match the circumference of the cylinder.

the machine:
glendon’s machine
Mechanically the machine is coming along fine. The cylinder is rotating on its axle. The motor is mounted and driving the cylinder via a rubber belt. The tape head is mounted on a small swing arm that slides back and forth across the surface of the drum. The little arm swings freely up and down so that gravity will keep it in contact with the surface of the drum. The user will slide it back and forth to select the tape. I am mounting the entire mini-cassette player that I took the head out of on the machine since I don’t want to figure out which parts of the circuitry are needed and which aren’t.

the tape head/arm:
tape head

Three important things remain to work out.

1. I need to make a speed control. Currently it’s running on a cell phone tranformer which gives a very
steady 5.2 VDC. The motor can run on up to 12VDC, maybe more. I need to get a higher voltage tranformer and put a simple voltage divider with a potentiometer to give me variable speed control. This is going to be important because if this thing will have any possiblity for expressive performance, it will probably come from having subtle and sensitive speed control. I will probably run it through a (homemade) volume pedal as well for a little extra performance control.

2. I need to record the content, the actual sounds. This is obviously going to have the largest effect on the ultimate sound of the machine. If I can lay my hands on a reel to reel taper recorder I hope to try that out in order to get wider and perhaps higher output tracks on the tape. The recorded tracks on a cassette are extremely narrow. There are actually 4 tracks on a tape abut 1/4” wide. I think a two track ¼” tape such as most reel to reels would make it easier to really get the head over the recorded sound.

The choice of sounds is more of a question at this point. I plan to record the sounds myself but some of them could be samples of existing music.

3. I need to figure out the best way to attach pieces of tape to the surface of the drum. I’m thinking of spray mount.

Some technical details:

The motor is a “gear head motor” which is like a normal DC motor but with a gear assembly that reduces the RPMs. This is an excellent type of motor for many applications because it delivers much more power at a more useful speed. Most DC motors run at hundreds or thousands of RPMs. Motors with gear reduction can run at much lower speeds. I got mine on eBay. Its range is between 100 and 200 RPMs.

For the drive belt I used a piece of a bicycle inner tube. Inner tubes are a great resource for any type of rubber belt or band. Cross sections make a very strong and super-durable rubber band of whatever width is needed. Using a tire patching kit, any strip of inner tube can be glued to itself to form a longer band of whatever size (not as strong as a cross section).

My Robots

Thursday, November 15th, 2007

Hello all,

As you know, my instruments are my two little robots named Freddy and Teddy.

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Shown below is Freddy and my dog Penny. (not sure why they are sideways, the editor is giving me a hard time) He is an older robot with a highly integrated circuit board and therefore I couldn’t get much actual bending accomplished with him. So instead, I am using a potentiometer to distort his sounds to create very interesting new ones. Freddy can say every letter in the alphabet, tell time, use a cell phone, tie his shoe, cross the street and sing a song. He can also store a sequence of numbers and say them back to you if you use his cell phone. He is smart.

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Below is Teddy a modern talking robot with an LED screen. Teddy is bilingual and can speak English and Spanish. He can count, go through the alphabet and sing a silly song. I was able to bend Teddy’s sound by pressing on the circuit board with a screwdriver as shown. I can control the pitch and distort the sound a bit.

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Unfortunately, I misplaced my guitar cable so I can’t connect these guys to my computer (I think I left it in class one day). I plan on recording their sounds for the world to hear tomorrow.