Mittwoch, 22. Oktober 2008

Hi-Hat's Module Demo Video

This video shows the sound of the hi-hats module. This is certainly the most 'musical' one of all videos since i'm trying to play rhythmic patterns with the 'open' and 'closed' hi-hat sound, habe fun!

Another Demo Video: The Tom Module

Here's the second video of a serie of three video's i recorded recently, my spoken english is improving slowly but steadily i guess.. Anyway here's the demo of the tom emulating synth.. enjoy!

Crash Ride Module Demo Video

Finally i managed to get time to turn some demonstration video. This one's about the not so peacefully sounding crash ride emulation. I worked on the sound of the demo videos a bit, mainly because i got my mixing table back from rehearsal room i once used. The sound of the modules heard is comes directly from the line input of the audio interface. My explanation are recorded through the camera, thats why the synth sound are crystal-clear and the narrating isn't. Have Fun!

Freitag, 17. Oktober 2008

Tom Module Concept

Oops, i forgot to put the concept of the tom module on this site.. by the time it's already finished, anyway... The sound source is a 'true' sine wave oscillator.
This means that the sinewave is generates using a 18dB/oct filter made to resonate permanently. On other synth vco's sine wave are sometimes generated by 'bending' a triangle-wave into a sine wave. The difference between a true sinewave oscillator and a 'bent' sine-oscillator is only noticeable in fast frequency modulation. Due to it's nature the sinewave gets asymmetric generating overtones. I wanted a very clean sounding tom (as a counterweight to the more rough sounding bassdrum) so i realized a true sinewave oscillator. Frequency and volume can be/is modulated with two decay-only envelopes..
p.s. for sake of simplicity and layout esthetics (see post below) i omitted the distortion unit, that anyway contradicts the paradigm of a clean sounding tom

Some layout changes

The drumsynth project is progressing well, currently basic versions of all the sound modules are built (except for the 'sampler', this is gonna be either a circuit-bent mp3-player controlled by an atmega8, or an atmega16 which plays 'computed' samples). Also the mixer part, the device which sums up all the individual sound sources is finished and partly tested. For testing i attached only the bass drum to the sequencer and played around.. great fun.. can wait for the thing to be finished!!

For the sake of order i removed the 'distortion' knob on the tom module so that all the modules expect the snare have the same height. To make the layout a little 'sexier' in added some decoration (paying tribute to my patron and mascot LB ;-) ).
Here is how the new layout looks like:

Crash Module Design Changed

Currently the last sound module is being finished. While testing the sound i made some changes in the design. In the new design the phaser 'position' can be changed with the amplitude envelope as well, the amount of envelope in the phaser 'position' can be controlled with a knob. On the other hand the high-pass filter has been omitted. With this configuration some very cool sound ranging from starting jets up to something similar to gunshots can be realized, not really what you expect from a crash cymbal, but definitely unique!

Dienstag, 7. Oktober 2008

Trial and Error vs. Abstract Math

Before putting any new info about the other sound modules i'd like to talk a little bit about the electronic design 'strategies' i used to create the schematics. A lot of this was done base on a trial and error approach without really calculating exact values for the resistors and capacitors. Usually this worked quite well, since a lot of design ideas are taken from other schematics that already have shown to work. For some things however it's good to force yourself to go through the entire math to see whats happening in the circuit.

For the last module (the crash) i'm gonna use a phase shifter to shape the sound. For this had no idea which values to use so i was forced to go through the calculation. Also almost no (understandable) info was on the web so i decided to uncover the working mechanism of a phase-shifter or allpass myself. I put the results together in a short article (if the link doesn't work copy in the adress bar of your browser. I hope that the document is helpful for others everything is there is correct.

Samstag, 4. Oktober 2008

Sequencer Finished

The sequencer part is finished! I finally found all the major bugs in the firmware for the two atmega8 microcontrollers. I'll publish the source code under gnu public licence on this site as soon as it's cleaned up a little. I've made video showing the functionality of the sequencer, enjoy!.