Vax Serial text to Midi for Kraftor
This firmware allows Kraftor to trigger VAX speech from MIDI notes.
The sentences are edited and stored in Kraftor using a serial terminal software.
| Date | Revision | Changes |
|---|---|---|
| 2025-09-13 | 0.2 | Modified text parser |
| 2025-09-01 | 0.1 | initial release |
Connections
- Serial USB: Connect your favorite serial terminal to Kraftor via USB at 115200 bauds.
- MIDI: Connection can be made via USB or TRS MIDI type B.
You can also use Echo, our Serial terminal that runs in a browser!
You can also use Vax vox designer to tune the voice with a graphical interface and a dedicated app that also runs in the browser :
You can also sequence the phoneme with pitch and duration
using this tool :
Testing Sentences
Type the command /h for help. You should see the following command list:
/a = about this code
/c = clear display
/h = display help
/i = info about the current voice settings
/d = design voice (e.g. /d ap 50 pr 20 br 10)
/o = original voice settings
/rxxx = voice rate (75-600)
/m = show MIDI settings
/vx = set voice number (0-8)
(Paul, Harry, Betty, Ursula, Dennis, Kit, Frank, Rita, Wendy)
[Enter] = type your text, then press enter to start speech
@ = use as MIDI note delimiter
You can now type some text and press Enter to hear the speech. Use the /r command to change the voice rate and the /v command to load a voice.
Phonetics
You can also use DECTalk phonetics between brackets to correct a pronunciation or to have it sing :
interpol and [D OW T SH AH<50>] bank [W IY<500,90> AA<500,90> R DH AH R OW<500,90> B AA<200,5> T S]
Designing Voices
Use the /d command to design your own voice. Refer to the DECtalk user guide for more information about the various voice parameters. Check also the VAX vox user manual.
Try these examples:
/d br 50 qu 100 ap 60 sr 0 hr 0 la 0 hr 30 /d ap 90 pr 0
| Option | Effect |
|---|---|
| ap | Average pitch, in Hz |
| as | Assertiveness, in % |
| b4 | Fourth formant bandwidth, in Hz |
| b5 | Fifth formant bandwidth, in Hz |
| bf | Baseline fall, in Hz |
| br | Breathiness, in decibels (dB) |
| f4 | Fourth formant resonance frequency, in Hz |
| f5 | Fifth formant resonance frequency, in Hz |
| hr | Hat rise, in Hz |
| hs | Head size, in % |
| la | Laryngealization, in % |
| lx | Lax breathiness, in % |
| nf | Number of fixed samples of open glottis |
| pr | Pitch range, in % |
| qu | Quickness, in % |
| ri | Richness, in % |
| sm | Smoothness, in % |
| sr | Stress rise, in Hz |
| sx | Sex 1 (male) or 0 (female) |
Preparing Your Sentences for MIDI Triggering
Use the @ delimiter to slice your entry into different sentences. Each sentence will be triggered by consecutive MIDI notes starting at note 36. Example:
$ @one@two@three@four $ MIDI Note: 36: one MIDI Note: 37: two MIDI Note: 38: three MIDI Note: 39: four $
MIDI Trigger
In your sequencer, select Kraftor as the MIDI USB input. Triggering MIDI notes will play the corresponding sentences as defined above.
Firmware
Do not use this firmware for EMY or Terminal.
