M I D I D R A W B A R

USER'S MANUAL (HTML Version)




CONTENTS

Introduction
Unpacking the MIDI Drawbar
Control Layout Diagram
Rear Panel
Front Panel
What Are Drawbars?
Historical Organ Information
Using the MIDI Drawbar with the V3
Using the MIDI Drawbar With A Sequencer
Using the MIDI Drawbar as a Continuous Controller
Setting the MIDI Channel
Specifications
Warranty

Manual Rev H3.0 (HTML version)


Introduction

The MIDI Drawbar provides a convenient method of accessing MIDI parameters and controls in real-time. It can be velcroed onto a keyboard controller allowing for an ergonomic placement of controls. MIDI audio mixing, MIDI lighting, and synthesizer control are some of the possible uses for the MIDI Drawbar.

The MIDI Drawbar makes an excellent companion to the V3 Tone Wheel Organ Synthesizer. Instant access to the most important V3 controls can easily be achieved by pushing labeled buttons, turning knobs, or moving drawbars.


Unpacking the MIDI Drawbar

Inside the MIDI Drawbar carton you will find the following:
  1. MIDI Drawbar unit
  2. 12 volt AC adapter
  3. user's manual
  4. Velcro strips
  5. Envelope containing 4 control knobs
  6. warranty card
Please return the warranty card soon after your purchase. This card will allow Voce to keep you informed of updates and new products.

Velcro is a registered trade mark of Velcro USA Inc.


Rear Panel

The MIDI Drawbar rear-panel contains mostly connectors. Refer to the diagram on page 2. The labels for the rear-panel connectors and switches are on the top face plate. You'll find the following on the rear-panel:

  1. POWER SWITCH - push on / push off switch
  2. POWER JACK - The 12-volt AC wall adapter connects to the MIDI Drawbar via this connector.
  3. MIDI OUT - 5-pin DIN MIDI output. This MIDI output is used to send merged data from the MERGE IN input and front-panel controls to an external MIDI device such as the V3.
  4. MIDI MERGE in - 5-pin DIN MIDI input. This MIDI input is used to merge MIDI data from a keyboard or computer with MIDI data created by the MIDI Drawbar.
  5. EXPRESSION PEDAL input - A potentiometer or control voltage foot pedal can be connected to this input to send MIDI control #8. This 1/4" stereo jack conforms to the following specification: Tip=control voltage input, Ring=510 ohm resistor connected to 5 volts, Sleeve=ground. For a control voltage foot pedal use positive 0 to 5 volts connected to the Tip and the Sleeve is grounded.
  6. FT SW - tip/ring/sleeve type 1/4" connector for attaching momentary foot-switches for toggling the Slow/Fast and Brake functions. Tip and sleeve is the connection for the Slow/Fast function while ring and sleeve is the connection for the Brake function.
  7. MIDI CH - 16-position rotary switch. Selects basic MIDI channel.
  8. MAIN/AUX switch - selects whether the drawbars send to the main V3 drawbar control numbers or the AUX morph drawbar control numbers. (AUX is mainly used for a second set of drawbars on a manual).
Front Panel

There are three types of controls provided for the user on the MIDI Drawbar. Refer to the diagram on page 2. Section 1 contains nine push-button type controls with associated indicators, section 2 contains four rotary controls (knobs), and section 3 contains nine drawbars.

When used with the V3, these three types of controls provide the user with instant access to many of the V3's controls and parameters. The MIDI Drawbar can send fourteen different continuous-controller messages as well as nine different switch type MIDI control messages. The MERGE input provides a useful way of combining information from a keyboard or MIDI sequencer with MIDI data created by the front-panel controls.


What Are Drawbars?

This section will describe the use of drawbars in an organ context, for example, using the MIDI Drawbar with the V3 Tone Wheel Organ Synthesizer. The MIDI Drawbar need not be used for organ applications; its drawbars can be used for many application such as the volume faders of a MIDI mixer, or reverb time of an effects processor.

Tone-wheel organs use drawbars in a way which is analogous to the faders of a graphic equalizer. While a graphic equalizer modifies the timbre of a sound, drawbar synthesis creates timbres. This is actually a form of additive synthesis. Harmonic levels are increased by pulling drawbars out and decreased by pushing them in. As with a graphic equalizer, drawbars are also arranged with ascending frequencies from left to right. The 2nd drawbar from the left is an exception to this arrangement rule (see the Historical Organ Information section).

For example, if the leftmost drawbar is the only drawbar pulled out, the sound produced will be a low-frequency sine wave. A sine wave has no harmonic overtones. This makes sense; there is no other drawbar pulled out.


Historical Organ Information

Organ registration conventions have developed over many centuries. Referring to the drawbar diagram on page 2, you will notice pipe footages associated with the drawbars. This notation is a throw-back to the days of pipe organs.

Pipe organs produce sound by introducing noise (turbulent air) into tuned resonators (pipes). An organ flute pipe sounds like a flute and is the most pure sounding (free of harmonics) type of organ pipe. This is the type of sound produced by playing a note on a tone-wheel organ with a single drawbar pulled out.

A flute pipe's frequency is roughly dependent on its length. The longer the pipe, the lower its frequency. Notice that the footages decrease for drawbars going from left to right. This agrees with the graphic equalizer analogy: The frequencies get higher going from left to right. If the pipe footages for the drawbars are divided into the first drawbar footage (16'), the relationship between the drawbar's harmonic frequencies can be seen. This relationship is shown in the diagram on page 2 below the footages.

Notice that the white drawbars have harmonic frequency relationships which are powers of two (2, 4, 8, and 16). This type of harmonic relationship is one in which the tones are related by octaves. The octave relationship is considered to be a "pure" relationship and that is why the white color is used to denote these drawbars. Drawbar harmonics which are not an octave apart from the white drawbars are indicated by their black-colored handles.

Many people wonder why the first drawbar (16') is not white and why the second drawbar appears to violate the low to high harmonic arrangement. Traditionally the 8' stop (drawbar) is thought of as the fundamental tone, therefore all harmonic frequencies below the fundamental tone or less than an octave above the fundamental are known as sub-harmonics. These subharmonic drawbars are designated by a brown-colored handle.

Using The MIDI Drawbar With The V3

The MIDI Drawbar may be easily used with the Voce V3 organ module. The factory default MIDI map called "Normal" is set to function with the MIDI Drawbar and requires almost no programming. The only exception is the BRAKE foot-switch which requires the V3's brake control number be set to 74.

The MIDI drawbar and the V3 are connected in the following manner:

  1. A keyboard or sequencer's MIDI output is connected to the MIDI Drawbar MERGE IN.
  2. The MIDI Drawbar MIDI OUT is connected to the V3's MIDI IN.
The second step for configuring the MIDI Drawbars for use with the V3 is to set the MIDI channel selector switch. It should be set to the same channel as the keyboard or sequencer. See the MIDI drawbar manual if you are unsure about this operation.

The functions of the push-buttons when the MIDI Drawbar is used with the V3 are as follows:

VIBRATO / CHORUS ON - Turns on the V3 vibrato or chorus effect depending on the state of the VIBRATO / CHORUS SEL switch. If the chorus indicator (next to the VIBRATO / CHORUS SEL switch) is lit, the effect will be chorus rather than vibrato.

VIBRATO / CHORUS SEL - the change in the chorus or vibrato effect is only meaningful when the VIBRATO ON indicator is lit. This switch has two functions:

  1. It selects whether the chorus or vibrato effect is turned on in the V3.
  2. It sets one of three effect depths (C/V 1, C/V 2, and C/V3).
Pushing the VIBRATO / CHORUS SEL button steps through the six possible states of chorus or vibrato and depth.

ROTATING SPEAKER ON - Turns on the rotating speaker effect. This switch does not speed up and slow down the rotating speaker effect (see ROTATING SPEAKER FAST); it is an effect bypass.

ROTATING SPEAKER FAST - Toggles between the acceleration and deceleration rotating speaker effect states in the V3 when the ROTATING SPEAKER ON switch is turned on. The foot-switch input also toggles this switch.

PERCUSSION ON - Turns on the V3 Percussion effect. The Percussion effect is similar to the sound produced when a xylophone is struck. When the percussion effect is not on, the state of switches PERCUSSION VOLUME, PERCUSSION DECAY, and PERCUSSION 2ND/3RD will not affect the sound produced by the V3.

PERCUSSION VOLUME - Toggles between two initial attack volumes for the V3 percussion effect. These volume values are programmed into the V3 preset. This switch will affect the sound produced by the V3 only if the PERCUSSION ON indicator is lit.

PERCUSSION DECAY - Toggles between two decay rates for the V3 percussion effect. These rate values are programmed into the V3 preset. This switch will affect the sound produced by the V3 only if the PERCUSSION ON indicator is lit.

PERCUSSION 2ND/3RD - Toggles between two percussion harmonics for the V3 percussion effect (nominally a 2nd or 3rd harmonic of the fundamental). This switch will affect the sound produced by the V3 only if the PERCUSSION ON indicator is lit.

RE-XMIT / SAVE - is a dual-function button. The first function is to send the state of all of the MIDI DRAWBAR's controls (drawbars, knobs, and switches) to the V3. This is useful if the V3 state is unknown such as when the V3 is first turned on or the V3's program number is changed. The second function of this push-button is to activate the remote save function of the V3. All patch parameter and rotating speaker settings are saved to the current patch number by holding down the DRAWBAR / SAVE button for approximately four seconds. All the front-panel indicators will light, indicating the save function was performed.

The functions of the rotary controls when the MIDI Drawbar is used with the V3 are as follows:

VOLUME - a standard MIDI continuous controller volume control.

OVERDRIVE - controls the V3's overdrive mix parameter.

KEY CLICK - adjusts the V3 key click (attack) volume parameter. Key click is an electrical noise generated in tone wheel organs by the mechanical bounce of nine key contacts. It will be necessary to restrike any notes being held on the keyboard to hear the change made to the sound since key click occurs on the attack of the note.

LEAKAGE - adjusts the level of the V3's generator leakage. Generator leakage is the sound created by the crosstalk of the tone-wheels in a B-3. It's a breathy ethereal sound keyed in beneath the main sound.

The functions of the drawbars when the MIDI Drawbar is used with the V3 are as follows:

Drawbar changes can be used to update the main drawbar settings of the V3 or the morph (AUX) drawbar setting of the V3. Any changes to the drawbars are instantly reflected by the V3 provided the morph control is set to reflect the drawbar changes (MAIN or AUX) which are sent.


Using the MIDI Drawbar With A Sequencer

The best way to record drawbar changes and other MIDI control changes produce by the MIDI Drawbar is to record from the THRU output of the V3 (or the next module after the MIDI Drawbar). This will allow note on/off information as well as control changes to be saved in a MIDI sequence. Its best to press the RE-XMIT button at the beginning of a sequence in order to save the state of the MIDI Drawbars in the sequence.

To play back a MIDI sequence, connect the MIDI out of the sequencer directly to the V3 (or other sound module). It is also possible to view the push-button changes as they occur in the sequence by connecting the sequencer's MIDI output to the MIDI Drawbar input. The MIDI Drawbar is capable of displaying control changes it detects at its Merge Input which coincide with its push-buttons' control numbers. These changes will light the push-button indicators accordingly. For example: if control number 68 is detected at the Merge Input it will set the Rotating Speaker Slow/Fast indicator to reflect this change.


Using the MIDI Drawbar as a Continuous Controller

The MIDI Drawbar to be used as a general purpose MIDI control box and a merger. Fourteen continuous controllers and nine push-button / foot switch controllers can be merged with a keyboard or sequencer output. Many modern synthesizers and effect processors can use external continuous controllers to modify parameters in real time. Control of these parameters in real time has live performance applications, as well as reducing the time it takes to program sound modules and effect processors. The MIDI Drawbar also makes an excellent controller for MIDI lighting and mixing applications.

To use the MIDI Drawbar as a continuous controller: connect the device receiving MIDI data to MIDI OUT of the MIDI Drawbar. The MIDI Drawbar MERGE IN allows another MIDI controller's MIDI out to be connected and merged with the data generated by the MIDI Drawbar.

The functions of the push-button switches when used as a continuous controller are as follows:

1. VIBRATO / CHORUS ON - sends MIDI control number 95.

2. VIBRATO / CHORUS SEL - sends MIDI control number 93. The functions for the various data values are the following:
 
MIDI DATA VALUE SENT FUNCTION
18
Vibrato Mode, level 1 (C / V 1 Lit, CHORUS Off)
36
Vibrato Mode, level 2 (C / V 2 Lit, CHORUS Off)
58
Vibrato Mode, level 3 (C / V 3 Lit, CHORUS Off)
79
Chorus Mode, level 1 (C / V 1 and CHORUS Lit)
100
Chorus Mode, level 2 (C / V 2 and CHORUS Lit)
122
Chorus Mode, level 3 (C / V 3 and CHORUS Lit)

3. ROTATING SPEAKER ON - sends MIDI control number 94.

4. ROTATING SPEAKER FAST - sends MIDI control number 68. The foot-switch will also toggle this control.

5. PERCUSSION ON - sends MIDI control number 73.

6. PERCUSSION VOLUME - sends MIDI control number 71.

7. PERCUSSION DECAY - sends MIDI control number 70.

8. PERCUSSION 2ND/3RD - sends MIDI control number 72.

9. RE-XMIT / SAVE - is a dual-function button. The first function is to send the state of all of the MIDI DRAWBAR's controls (drawbars, knobs, and switches) to the V3. This is useful if the V3 state is unknown such as when the V3 is first turned on or the V3's program number is changed. The second function of the DRAWBAR / SAVE button is normally used to save control settings when the MIDI Drawbar is used with the Voce V3. By

holding down the DRAWBAR / SAVE button for approximately four seconds, the MIDI Drawbar unit will send a MIDI control number 102 with its data byte set to a value of 127. All front- panel indicators will light, indicating the save function was performed. This function will not re-transmit the controller values unless the button is released before the four-second period is over.

The functions of the rotary controls when used as a continuous controller are as follows:

1. VOLUME - sends MIDI continuous controller number 7.

2. OVERDRIVE - sends MIDI continuous controller number 91.

3. KEY CLICK - sends MIDI continuous controller number 89.

4. LEAKAGE - sends MIDI continuous controller number 90.

The function of the drawbars when used as a continuous controller are as follows:

The drawbars send a range of MIDI continuous controller numbers starting with controller number 12 for the first drawbar and 20 for the last. For example the fifth drawbar sends MIDI continuous control number 16.

The table in the following page summarizes the MIDI control numbers transmitted by the MIDI Drawbar unit and the standard MMA (MIDI Manufacturer's Association) usage:
 
Cont. #
MMA use
MIDI DB
7
Volume
Volume
8
Balance
Expression Foot Pedal
12
-
Drawbar #1 (MAIN)
13
-
Drawbar #2 (MAIN)
14
-
Drawbar #3 (MAIN)
15
-
Drawbar #4 (MAIN)
16
GP cont #1
Drawbar #5 (MAIN)
17
GP cont #2
Drawbar #6 (MAIN)
18
GP cont #3
Drawbar #7 (MAIN)
19
GP cont #4
Drawbar #8 (MAIN)
20
-
Drawbar #9 (MAIN)
21
-
Drawbar #1 (AUX)
22
-
Drawbar #2 (AUX)
23
-
Drawbar #3 (AUX)
24
-
Drawbar #4 (AUX)
25
GP cont #1
Drawbar #5 (AUX)
26
GP cont #2
Drawbar #6 (AUX)
27
GP cont #3
Drawbar #7 (AUX)
28
GP cont #4
Drawbar #8 (AUX)
29
-
Drawbar #9 (AUX)
68
Legato
Fast/Slow
70
-
Percussion Decay
71
-
Percussion Volume
72
-
Percussion Harmonic 
73
-
Percussion On/Off
74
-
Foot-Switch Brake
89
-
Key Click Volume
90
-
Hum
91
External Effects Depth
Distortion
92
Tremolo Depth
RS On/Off
93
Chorus Depth
Vibrato/Chorus Depth
95
Phaser Depth
Vibrato/Chorus On/Off
102
-
Save Function


Setting the MIDI Channel

Set the MIDI Channel selector switch to the desired MIDI channel according to the following table:
 
MIDI CHANNEL
SWITCH POSITION
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
0


SPECIFICATIONS
 


WARRANTY