Programming the Roland TB-303
start | | | Sequencer | | | Sound: | signal flow - vco - accent | | |
accent
More on the workings of the "Accent" pot can be read in the article "Robin Whittle explaining some aspect of the 303 sound".
A quote from this article:
"The real fun happens when you have multiple accented notes in quick succession. Since the capacitor has not discharged fully from the one before, the second and subsequent response curves go *higher*".
To understand what is meant here, I created a pattern containing only C-pitches with Accents:
Download TB-303 Saw wave with only Accents (17 seconds, 400 KB mp3)
And this is how it looks like in a Frequency Analyzer (it is the same sound file before it was mp3'd):
0 sec. | 17 sec. |
I totally do not understand the (at some points) three layers of resonance in the sound. What is going on here? Incredible.
Anyway, it gives the effect of listening to a note with the feeling of an ever-ascending pitch, the same as the trick YMO used in Loom (1981, YMO "Loom" on Youtube, you hear the effect from 0:30 to 2:00). This is called a Shepard tone.
The sound file was created using the following settings.
Here's the explanation: to get the best audible effect, you need loads of Resonance, and of course maximum Accent. Decay doesn't work with accented notes, so any setting will do. Also, you have to tweak the TEMPO knob for the speed of the retriggering effect. When I turned the TEMPO a millimeter up, the effect was that of the pitch going down in stead of up. "Tuning" is low, and "Cut off" is at a third so the low-pass filter has a lot of headroom to open up. Which is exactly what you hear.
I say it's the sound of dripping acid...