Wavetable Sounds Tutorial #3

WARNING: This tutorial describes features of MIDIbox SID V1 - they are partly handled on a different way in MIDIbox SID V2. More details can be found in the MBSID V2 User Manual.

This tutorial session does focus on arpeggiator textures made with the sequencer of MIDIbox SID. All patches which are discussed below can either be entered with the JSynthLib based editor, or directly from the Control Surface. The ready made patches can be downloaded from this location.

mbsid_tutor_short_arp.mp3
Short Arpeggios
In this example, arpeggios are created in the same manner like known from old C64 tunes. A wavetable is used to control the waveform, and the transpose value of one or all three voices. The wavetable is played with a high rate. This method is also known as "broken chords" - the notes of a chord are played so fast, that one could think, that they are played simultaneously.

create a new patch, set Pulse wave for all three oscillators.
Assign LFO1 to Pulsewidth of Voice1, LFO2 to PW Voice2, LFO3 to PW Voice3 - Depth ca. +/- 8 (vary between LFOs), Rate ca. 85 (very between LFOs)
assign track 1 of the Wavetable to CC#32 (Voice 1/2/3 Waveform)
assign track 2 of the Wavetable to CC#16 (Voice 1/2/3 Transpose)
Wavetable Rate: start with 1, increase to 115 (which corresponds to 50 Hz update rate)

enter following sequence:
STEP CMD #1 #2 00 Play 04 40 01 Play +00 43 02 Play +00 47 03 Play +00 4C 04 Play +00 40 05 Play +00 43 06 Play +00 47 07 Play +00 4C 08 Play +00 40 09 End +00 +00

This wavetable will roll the transposed notes of a major chord exactly 2 times, thereafter the gate will be released (sound will stop).
In difference to the Arpeggiator, which runs separate from the wavetable, this method has the advantage, that only a single key needs to be pressed on a MIDI keyboard to play an arpeggio. The Arpeggiator requires to play the whole chord (up to 4 keys). But you can also see the disadvantage: always the same chord type is played, e.g. it is not so easy to switch from major to minor by using this method.
A possibility to overcome this limitation is the use of CC#12 ("Select Wavetable Patch Number"). You could prepare several wavetables in different patch slots, and switch over to it while playing without switching to a new patch.

mbsid_tutor_arp_notes.mp3
Arp Notes
A much more flexible way to create arpeggios is one of the special features of MIDIbox SID: Notes can be directly played from a Wavetable (like if you would play it from a sequencer), and it's not only possible to play and transpose static notes sequences (hex code 02-7B), but chords played on a keyboard can also be directly forwarded to the sound engine (hex code 7C-7F).
In the JSynthLib editor, these special chord notes are accessible with the keywords "KEY1", "KEY2", "KEY3" and "KEY4". The Control Surface uses the same name - just turn the encoder full right until you see "KY1".."KY4".
Following example should give you a starting point:

create a new patch, change from Mono mode to "WT Seq Only" - now the notes being played are under direct control of the WT sequencer.
assign track 1 of the Wavetable to CC#8 (Voice 1/2/3 Note)
assign track 2 of the Wavetable to CC#16 (Voice 1/2/3 Transpose)
Wavetable Rate: 36 (slow)

enter following sequence:
STEP CMD #1 #2 00 Play KEY1 40 01 Play KEY2 40 02 Play KEY3 40 03 Play KEY1 4C 04 Play KEY1 40 05 Play KEY2 40 06 Play KEY3 40 07 Play KEY1 4C 08 Goto 00 +00

just play different chords on the keyboard and have some fun :)

mbsid_tutor_arp_notes2.mp3
Arp Notes #2
In the previous example, the purpose of the hex codes 00 and 01 were not mentioned. So: 00 (or in JSynthLib: "---") is used to release the gate, and 01 (JSynthLib: "+++") is used to hold the gate.
The following example goes a little bit further. The wavetable is clocked from an external MIDI sequencer in order to keep MIDIbox SID in synch with a drum machine:

create a new patch, change from Mono mode to "WT Seq Only" - now the notes being played are under direct control of the WT sequencer.
assign track 1 of the Wavetable to CC#8 (Voice 1/2/3 Note)
assign track 2 of the Wavetable to CC#16 (Voice 1/2/3 Transpose)
Wavetable Rate: 123, enable MIDI clock synchronization (Control Surface: CFG menu, "Clk" parameter)

enter following sequence:
STEP CMD #1 #2 00 Play KEY1 34 01 Play --- 34 02 Play KEY2 34 03 Play --- 34 04 Play KEY1 40 05 Play --- 40 06 Play KEY2 40 07 Play --- 40 08 Play KEY1 4C 09 Play --- 4C 0A Play KEY2 4C 0B Play --- 4C 0C Goto 00 +00

start your MIDI sequencer (in order to send a MIDI clock to MIDIbox SID), and press two notes on a keyboard, or send them from the sequencer.
The MIDI clock divider can be controlled with the WT rate, here some typical values:
- 126: 8 WT steps = 1/4 note
- 123: 8 WT steps = 1/2 note
- 117: 8 WT steps = 1 note

mbsid_tutor_poly_arp.mp3
Polyphonic Arpeggios
With the last example of this session I would like to highlight, that polyphonic arpeggio textures can be created by using all three tracks of the wavetable sequencer:

create a new patch, change from Mono mode to "WT Seq Only" - now the notes being played are under direct control of the WT sequencer.

use similar sound settings for all three voices.

assign track 1 of the Wavetable to CC#9 (Voice 1 Note)

assign track 2 of the Wavetable to CC#10 (Voice 2 Note)

assign track 3 of the Wavetable to CC#11 (Voice 3 Note)

Wavetable Rate: 123, enable MIDI clock synchronization (Control Surface: CFG menu, "Clk" parameter)

enter following sequence:
STEP CMD #1 #2 #3 00 Play --- KEY2 KEY3 01 Play --- --- --- 02 Play KEY1 --- --- 03 Play --- KEY2 KEY3 04 Play --- --- --- 05 Play --- KEY2 KEY3 06 Play KEY1 --- --- 07 Play --- --- --- 08 Goto 00 +00

For more inspirations, just have a look into the patch settings A064-A076 of the MIDIbox SID preset library.

Wavetable Sounds Tutorial #3

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