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Audio Input Sources continued...

The deMIDulator headset jack input expects an Electret-type microphone similar to that found in the 
iPhone earbuds headset.

For advanced users:  

The Electret MIC bias is set by R23/R24.  You can change the value of this 

component or remove it entirely based on your microphone input needs.  Note that this will affect input 
from both the on-board PCB mic and the headset jack mic.

Other MIDI Implementation Details

Pitch Wheel

The deMIDulator currently implements Pitch Wheel in a mostly uncontrollable and unusable 
way.  It does however serve to create some interesting sounds.

In 

Sine

 and 

Square

 modes: Pitch Wheel Up and Down causes the pitch of the note output to 

bend wildly in the respective direction.  You'll notice that sometimes the bend will exceed the 
upper or lower note boundary and will seem to reverse the bend direction.  It's interesting.

In 

Sample

 mode: Pitch Wheel Up will cause the sample playback rate to increase.  Pitch Bend 

Down will slow the sample for a short range but bending further will cause the sample to halt 
playback.  Releasing the Pitch Wheel back to center after the sample has halted will cause the 
sample to resume payback from the beginning of the sample.  This allows you to precisely halt 
and re-trigger the sample.

Modulation

In 

Sine 

and 

Square 

modes: increasing the Modulation value introduces a proportional amount 

of distortion which is the result of simple hardware trickery.  Sometimes abandoning science 
yields pleasing results.

In 

Sample 

mode: the modulation value serves only to control the playback direction of the 

sample.  A modulation value 

<64

 

will cause the sample to play back in the same direction 

as it was recorded

.  A modulation value 

>=64

 

will cause the sample to play back in the 

opposite direction of which it was recorded

.

Note that changing the direction in mid-sample playback will only cause the remainder of the 
sample or a subsection of the sample to play back in reverse while the sample continues to 
play from beginning to end.  Explaining this is confusing but you'll understand once you play 
with it.  This allows you to create interesting effects without losing the timing and cadence of 
the original sample.

Attack / Release

In 

Polyphonic

 and 

Sustain

 modes for all waveforms, the deMIDulator supports MIDI Control 

Change Controller #s 73 (Sound Controller 4 – Attack Time) and 72 (Sound Controller 3 – 
Release Time). 

 Attack Time

 controls 

how fast

 the note sound transitions from

 completely 

silent to full volume

 when a Note On message is received.  

Release Time

 controls 

how fast 

the note sound transitions from 

full volume to completely silent

 when a Note Off message is 

received.  Attack Time == 127 and note will never sound, Release Time == 127 and note will 
never turn off.

deMIDulator v1.10 User Guide – document version 1.00

Page 12/17

Bad Handshake Electronics 2011

Summary of Contents for deMIDulator v1.10

Page 1: ...deMIDulator v1 10 User Guide 3K wordCount Version revision 1 00 deMIDulator v1 10 User Guide document version 1 00 Page 1 17 Bad Handshake Electronics 2011...

Page 2: ...mmary 5 Waveform Mode Selection 6 Playback Mode Summary 7 Playback Mode Selection 8 Recording a Sample Audio Loop Through Mode 9 Sample Mode Playback Triggering 10 Audio Input Sources 11 Other MIDI Im...

Page 3: ...specified by the author or licensor but not in any way that suggests that they endorse you or your use of the work Noncommercial You may not use this work for commercial purposes Share Alike If you a...

Page 4: ...sound generating arsenal This document will provide the information you need to successfully operate your v1 10 deMIDulator Overview of PCB Controls top view deMIDulator v1 10 User Guide document ver...

Page 5: ...volume can get very loud so make sure that the volume control is set to a low setting before turning the deMIDulator on Waveform Mode Summary The deMIDulator has three waveform output modes Sine wave...

Page 6: ...aveform Select button can only cycle the waveform mode in the direction of Sine Square Sample Sine MIDI Program Change can be used to cycle in either direction When a MIDI Program Change message is re...

Page 7: ...Blink Slowly Up to 4 MIDI notes may be played simultaneously Modulation Pitch values are ignored Amplitude Attack Release time envelopes are enabled Sustain mode is unique from the others in that cer...

Page 8: ...n mode Monophonic When in this mode The currently active waveform LED will Blink Quickly Only 1 MIDI note may be played at a time Modulation Pitch values may be changed Amplitude Attack Release time e...

Page 9: ...t Note that MIDI input is still processed while audio loop through is active After releasing this button in Sine and Square modes previous LED function will resume audio loop through will stop normal...

Page 10: ...hrase would then sound like I m just here I m just here I m just here I m just here I m just here I m just here I m just here You get it Sample re triggering is only active in Polyphonic mode When in...

Page 11: ...ols Aside from accepting a standard 3 conductor stereo headphone plug for audio output the headset jack also accepts a 4 conductor headset stereo audio microphone plug with the following pinout Pin Nu...

Page 12: ...sing the Modulation value introduces a proportional amount of distortion which is the result of simple hardware trickery Sometimes abandoning science yields pleasing results In Sample mode the modulat...

Page 13: ...messages will immediately begin transmitting via the MIDI output port See document mootLoaderTransmitterSpecification_v1_10 for more details Writing the firmware Writing your deMIDulator s firmware r...

Page 14: ...MIDI Implementation Chart deMIDulator v1 10 User Guide document version 1 00 Page 14 17 Bad Handshake Electronics 2011...

Page 15: ...m Off Yes No no DLS 1 Yes No no File Reference Yes No no Controller Destination Yes No no Key based Instrument Ctrl Yes No no Master Fine Coarse Tune Yes No no Other Universal System Exclusive no Manu...

Page 16: ...General Purpose Controller 3 MSB no 19 General Purpose Controller 4 MSB no 20 no 21 no 22 no 23 no 24 no 25 no 26 no 27 no 28 no 29 no 30 no 31 no 32 Bank Select LSB no 33 Modulation Wheel LSB no 34 B...

Page 17: ...ose Controller 5 no 81 General Purpose Controller 6 no 82 General Purpose Controller 7 no 83 General Purpose Controller 8 no 84 Portamento Control no 85 no 86 no 87 no 88 no 89 no 90 no 91 Effects 1 D...

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