Beatbox is a 4-voice, 16-step drum machine designed with easy programming and fast changes in mind. Each of the voices was designed to give a good variety of sonic character, from classic kick-snare-hat sounds to more exotic percussion.
Much more complex percussion voices and sequencing is possible within ZOIA; my focus here was to design something more focused on UI (which consumes a lot of the CPU’s budget, especially the ratcheting) that would make writing a simple drum sequence very straight forward: putting together a drum pattern is as simple as pressing buttons, with lots of visual feedback.
That said, the sequencers can be set to individual step lengths, which can be used to create polyrhythms that are more complex than the limitations of 16 steps might imply.
The patch is mono, with the drum voices being sent to both outputs; there is also a stereo path that goes directly from input to output, so you can pass audio through ZOIA while the patch is running.
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TL;DR:
I’m going to write a bunch of patch notes; it’s who I am. Reading them is probably useful, but if you just want to jump into the patch here’s what you need to know:
First page — voice parameters; tweak away; they’re designed to produce usable sounds in all settings
Second and third pages — buttons to set the sequence for each voice; on/off for voices 1-3; ratcheting for voice 4 (cycles through 1, 3, and 5 ratchets)
Controls (page 0–front page):
The front page is coordinated by color. At the top are controls for specific drum voices, with levels and mutes for each at the bottom of the page.
Blue (bass-tom)
The first voice is made from an envelope-controlled sine oscillator sent into a low-pass filter.
Tone — this is a combination pitch/filter frequency control; at its lowest settings it produces a deep kick; as the control is increased, the pitch modulation becomes more apparent, resulting in a voice more like a classic electric tom
Decay — controls the decay of the voice, from snappy to long decays (~2 seconds)
Magenta (snare-clap)
This is noise, passed through a VCA opened by trigger, then into a non-resonant bandpass filter. From there it passes through a short delay.
Tone — controls the frequency of the bandpass filter; the range of this control has been set to produce a wide variety of tones, but it has been constrained to ignore low and high frequencies that were not particularly useful
Time — sets the delay time; shorter values produce additional filtering; longer delays can be used to produce more clap-like sounds
Feedback — sets the feedback of the delay line; at short times, high feedback can produce quasi-Karplus-Strong sounds; at longer times it can lead to a thick repeated percussion that has a “loose” quality (to my ears)
Aqua (cymbal-perc-snare 2)
This is another voice derived from bandpass filtered noise. Here, however, the VCA is controlled by an AD envelope, and the filter is capable of achieving some slightly resonant sounds.
Attack — sets the attack of the envelope; longer attack times can produce sounds more like cymbals or even reversed-cymbals
Decay — sets the decay of the envelope; short times can produce hats, with longer times producing snares and cymbals
Frequency — sets the frequency of the bandpass filter, changing the sound and response of the noise
Resonance — controls the resonance of the filter; more resonant sounds will be “tighter”
White (hats-perc)
This is a voice made from unfiltered noise, passing through a VCA controlled by an AD envelope. (It is a copy of the magenta voice, without the filtering.)
Attack — sets the attack of the envelope; longer attack times can produce sounds more like cymbals or even reversed-cymbals
Decay — sets the decay of the envelope; short times can produce hats, with longer times producing snares and cymbals
Inputs (pages 1-2):
These feature rows of pushbuttons that are coordinated with the voices from the control page.
These are arranged in two rows over 16 buttons, such that button one represents step 1 in the corresponding sequence, except:
Voice 4’s input is limited to 8 steps, and where the rest of the inputs are simple on/off selections, voice 4’s input allows for setting ratcheting for this voice, making rolls possible:
1 press – 1 ratchet/simple “on” position.
2 presses – 3 ratchets
3 presses – 5 ratchets
With another press, the step will return to “off” position.
The brightness of the button increases with each press.
Although this voice is limited to 8 programmable steps; its sequencer is 16 steps long (step 1-8 double onto steps 9-16), which, by adjusting the step count of the sequencer can allow for more complex sequences.
Ins and outs (page 3):
Audio in, audio out. In the MIDI version, this is where the clock in module is, as well as a clock divider for the incoming clock.
Sequencers (pages 4-7):
The sequencers’ step length can be determined here. Simply place a gate–press the step, which will turn the gate on/off–corresponding to the step length you want on the corresponding step of track 2 (green track). Remove the gate to restore the sequencer to its original length.
Voices (pages 8-11):
The drum voices are placed here.
Ratcheting sequencers (pages 12-13).