Tonal Plexus TPX 6s, TPX 8s User Manual
CONTENTS
1. Introduction ........................................... 1
Checklist ........................................ 2
Recommended Accessories ........... 3
Overhead Diagram ........................ 4
Back Panel Diagram ...................... 5
LCD Display ..................................... 5
2. Keyboard Layout ................................... 6
From Piano to Plexus ..................... 6
Default Master Tuning .................... 7
Octaves and Fifths ......................... 7
Commas and JNDs ........................ 8
Key Diameter and Elevation ........... 8
3. Tuning Tables ........................................... 9
MIDI Mapping ................................... 9
Untuned Output Mode ...................... 10
Duplicate Keys ................................. 10
Programming a Tuning .................... 11
Local Control Switch ...................... 11
Octave Buttons ................................ 11
4. Polyphony .............................................. 11
5. Presets .................................................... 12
Storing a Table Preset ..................... 13
Storing a Patch Preset ..................... 13
6. Live Control ............................................ 14
Switches and Control Groups ......... 14
Hex Display ...................................... 15
Waveform Group (AC) ..................... 16
Equalizer Group (BC) ...................... 17
Effect Group (AD) .................................. 18
Modulation / Pitch Bend Group (BD) ..... 19
7. Joystick Option ............................................. 21
8. External MIDI Devices .................................. 22
Controllers ............................................ 22
Standard External Modules .................. 22
Natively Microtonal External Modules .. 22
Startup Sequence ................................. 23
9. Sequencer / MIDI Footswitch Control ......... 23
Patch Changes ...................................... 23
Bank Select .......................................... 23
Tuning Table Changes .......................... 24
10. DIP Switches .............................................. 25
Bank Select Format .............................. 25
Velocity Randomization Bandwidth ...... 26
Pitch Bend Response Timing ............... 26
Sysex Retransmission .......................... 27
Global Pitch Bend Mode ....................... 27
Sustain Pedal Polarity ........................... 28
Sysex Recovery Timing ......................... 29
APPENDIX ........................................................ 30
General MIDI Patch List ....................... 30
Hexadecimal Values .............................. 32
MIDI Implementation Chart .................... 33
System Exclusive Messages ................ 34
Troubleshooting ..................................... 35
Technical Specification .......................... 38
1. Introduction
The H-Pi Instruments Tonal Plexus TPX6s/8s is a hand-made instrument designed to be lightweight,
easy to use, and compatible with the widest range of existing MIDI hardware and software, allowing
easy exploration of the limitless universe of alternative tunings. Please refer to this manual to get the
most out of your keyboard.
Your input is appreciated. If you have a question or comment about something in this manual, or
something which is not addressed in this manual, please contact H-Pi Instruments via email at
contact@h-pi.com. In response to your input, this manual may be updated and made available for
PDF download from the H-Pi Instruments website at www.h-pi.com/downloads.html.
This manual was uploaded July 17, 2008 and is the first version of theTPX6s/8s manual. This manual
may be replaced at any time by another manual.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 1
Checklist
TPX6s/8s
Every TPX6s/8s unit is built by hand. Please do not be alarmed by any small blemishes you may find.
Always handle the unit with care.
International 12V 4.5A Power Supply
The power supply runs on 100 - 240V, 50 - 60Hz, and will work in most countries around the world –
just plug in a locally supported grounded cable (US standard cable shown above, left) or adapter.
Two MIDI cables (optional)
Having these items, you are ready to begin.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 2
Recommended Accessories
Sustain Pedal
Because TPX6s/8s has a sustain pedal polarity switch, all sustain pedals are compatible.
Volume Pedals
Volume pedals may be used to override top panel faders 2 and 3. The pedal should be 20KOhm.
High impedance guitar volume pedals will work, but not very well. The volume pedal we recommend is
made by in Italy by bespeco, and is available to European customers as the VM16L and in the US as
Quiklok VP16. This pedal is nice because it has the cable built in; however, it is no longer available in
the US. A slightly different pedal in stereo configuration with the handy addition of a lowest-volume
control pot is also available from bespeco as the VM14L, and fortunately this pedal is available in the
US as the Quiklok VP15. With this pedal, you will need to get a cable which is 1/4'' Stereo plug to 2
1/4'' Mono plugs (a.k.a a standard Send / Return Insert Cable), for example, the STP-200 from Hosa.
Having an internal synthesizer and amplifier, a TPX6s/8s keyboard is a standalone instrument.
However, if sounds other than those of the internal synthesizer are needed, the internal amplifier of
TPX6s/8s can be used with external sources by connecting External Source LINE OUT to TPX6s/8s
LINE IN. To save space, TPX6s/8s uses a Stereo (TRS) 1/4” jack for LINE IN, so that a cable adapter
may be needed to connect external sources having other types of output jacks. Adapter cables are
available from HOSA, shown below: a 1/4" Male Stereo to 2 Female Mono 1/4" Cable, a 1/4" Male
Stereo Phone to 2 RCA Female Cable, and a 1/4” Stereo to Stereo Mini Cable.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 3
16 Tuning Presets
Press these buttons
to recall a preset
tuning tables.
16 Patch Presets
Press these
buttons to recall
preset banks and
patches.
LOCAL CONTROL Switch
When Local Control is OFF, the blue
LED lights up, and only MIDI
received at MIDI IN travels to the
internal synthesizer, which can be
useful when working with
sequencing and notation software.
4 x 20 Character LCD
Displays the currently
selected preset tuning
table, bank, patch,
preset numbers, and
Live Control global
hexadecimal values .
Octave Up / Down Switches
Navigates the currently selected
tuning table by table octaves.
NOTE: In the default Master
Tuning, this corresponds to
transposition by octaves;
however, the pitches stored in
user tables may correspond to
anything, so shifting by table
octaves does not necessarily
require shifting by octaves in
terms of pitch.
TUNED OUTPUT Switch
ON: multi-channel pitch bend output,
for use with the internal synthesizer or
external MIDI gear; OFF: untuned raw
MIDI notes output, for use with external
retuning gear such as software
samplers and synthesizers.
16 Channel Switches
Use these switches to control
polyphony – which channels receive
tuned MIDI output.
NOTE: Channel 10 is MIDI
percussion
Faders 2 and 4
Fader 2 nromally
sends Key Velocity,
and fader 4 sends
MIDI Panning. In the
Live Control Matrix,
these faders send
various messages.
MATRIX ON / OFF
An LED shows the state of this switch
- OFF: the functions of the four faders
are 1 - Modulation, 2 - Velocity, 3-
Volume, 4 - Panning. ON: fader
functions are determined by the ROW
and COLUMN switches.
Overhead Diagram
ROW and COLUMN
Use these switches
to select from four
groups of Live
Control parameters.
MATRIX LEDs
These LEDs show
which ROW and
COLUMN of the Live
Control Matrix is
selected.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 4
Back Panel Diagram
MIDI IN
Connect
another MIDI
controller to
this jack, also
used for
uploading
tuning tabels
to the
keyboard.
MIDI THRU
This output
sends MIDI
data received
at MIDI IN
through
unmodified to
another MIDI
device.
MIDI OUT
Connect a
synthesizer,
sampler or MIDI
interface to this
jack to receive
retuned or raw
MIDI data on
selected MIDI
channels.
12V DC Input
TPX6s/8s
require at least
2.5 Amps.
Power switch
provided.
LINE IN
Input a line level
audio signal from
any other source
directly to the
internal amplifier
using this 1/4”
jack. NOTE: This
input turns off
internal audio.
LINE OUT
Output line level
audio from the
internal amplifier
to an external
device suxh as
a mixer or
amplifier using
this 1/4” jack.
Stereo Headphones
Connecting headphones
to this attenuated stereo
output turns off speaker
output.
Volume
Control the amplifier output
to either the speakers or the
headphones with this knob.
SUSTAIN
Connect a
sustain (a.k.a.
Damper) pedal
to this 1/4” jack.
Volume Pedals
Connect Lo-Z (22 kOhm)
volume pedals to these 1/4”
jacks to control MIDI Volume
and Key Velocity (these inputs
override top panel faders)
DIP Switches
Control nine
parameters at
startup using
these DIP
switches (see
Appendix)
LCD Display
The 4 x 20 character backlit LCD normal display is shown below.
This display changes format in the following situations:
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 5
1. when Tuning Table data is being programmed
2. when all TUNED OUTPUT CHANNELS are switched OFF
3. when the TUNED OUTPUT switch is set to OFF
4. when GLOBAL PARAMETERS are resetting
2. Keyboard Layout
The Tonal Plexus keyboard geometry was designed in 2002 by Aaron Andrew Hunt. This particular
geometry is unique in the history of the musical keyboard, although it bears resemblance to previous
inventions known as generalized keyboards, early examples of which are found in the work of Paul
Von Janko (1875) and R.H.M. Bosanquet (1877).
From Piano To Plexus
The Tonal Plexus keyboard layout is based on the traditional piano keyboard pattern of 7 white and
5 black keys, with standard fifths-based note names as shown below, piano keys carrying multiple
names as shown.
• 7 naturals
• 7 sharps
• 7 flats
• 7 double-sharps
• 7 double-flats
All standard note names correspond to unique, non-dulpicate keys on the Tonal Plexus. Extended
fifths-based note naming leads to a new set of enharmonics.
• 6 triple-sharps
• 6 triple-flats
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 6
These 12 new enharmonic keys are shown at the top and bottom edges of the layout, the blue keys
in the images above and Figure 1 below.
Figure 1
Default Master Tuning 205ET
The master tuning of the Tonal Plexus was determined by way of thorough research in music theory,
music notation, and pitch perception. The result is a system which allows the free exploration of all
possible pitch combinations in a coherent way, according to reasonable limits of human perception.
A few main concepts behind the master tuning are given below. Further information about the master
tuning will be made available in a separate document.
Octaves and fifths
Octaves and fifths define the basis of Western music theory and notation. Hence, these intervals
form the basis of the master tuning. Octaves are tuned purely, and fifths are tuned virtually purely,
with a deviation of less than half of one cent. These two intervals provide a reference for pitch
ordering and naming relative to which all other intervals are defined.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 7
Commas and JNDs
The master tuning is designed around the comma as a basic interval. The comma used is just under
30 cents in size, forming the basis of a key layout in which one octave contains 41 commas. To
maximize pitch control and expressivity, each comma is broken into 5 JNDs, so that the smallest steps
on the keyboard are just under 6 cents in size. Each octave contains 205 JNDs. Using JND fine
tuning, any interval can be played with a maximum tuning deviation of less than 3 cents. Though
under certain conditions such small mistunings can be heard, in practice the errors are so small that
they are not noticeable; other natural variables such as timbre and duration introduce similar small
margins of error. The master tuning is thus contains all pitches and intervals in a managable way.
Key Diameter and Elevation
Tonal Plexus keytops vary in diameter and elevation, arranged symmetrically in 41 regions per
octave. The center key of each region has a concave surface and is the largest in diameter. The
other keys are smaller and have flat tops. These variations of diameter and elevation provide a tactile
terrain for navigation of the keyboard by touch. In the default Master Tuning, the variations
correspond to JND inflections of a given letter name, allowing harmonic intervals to be easily found by
touch alone.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 8
3. Tuning Tables
Each tuning table provides a simple 1 to 1 correspondence between raw MIDI Notes played and
retuned MIDI Notes output. Any MIDI Note input can be retuned to any pitch output, in any register
with any frequency, limited only by the internal or external synthesizer.
MIDI
Note
played
Tuning
Table
lookup
Tuned
MIDI
Note
OUT
There are 32 memory locations, numbered 0 - 31, available for storing tuning tables. There are 16
preprogrammed default tuning tables, including the Master Tuning 205ET. The default tuning tables
may be overwritten, and there are no protected memory locations. Each table is given a 16-character
name. The name and number of the currently selected tuning table is displayed on the top row of the
LCD. For each MIDI Note, there are three values stored in the tuning table: MIDI Note, Pitch Bend
MSB and Pitch Bend LSB. When a MIDI Note ON message is received, these values are looked up
and immediately transmitted to MIDI OUT in the following order: Pitch Bend MSB, Pitch Bend LSB,
MIDI Note ON.
MIDI Mapping
Each octave of a Tonal Plexus keyboard uses two MIDI Channels, each assigned to six columns of
keys. These two MIDI Channels are shown as CHANNEL A and CHANNEL B in Figure 2 (next page).
The MIDI Note numbers are the same in each octave, and the MIDI Channels are fixed according to
the size of the keyboard. The chart below shows MIDI Channel assignments for TPX6s and TPX8s.
These MIDI Notes and Channels should be sent from external devices connected to MIDI IN.
OCTAVE
CHANNEL A
CHANNEL B
TPX8s
TPX6s
1234567813579111315246810121416XXXXXXXXXXXXX
X
MIDI Notes 0-104 are used from Channel A and MIDI Notes 0-105 are used from Channel B. This
leaves 22 MIDI Notes (105-127) unused on Channel A and 21 MIDI Notes (106-127) unused on
Channel B. These 43 unused MIDI Notes correspond to 43 unused Tuning Table Registers for each
Tonal Plexus octave. Although these free memory registers are ignored by the keys of a Tonal
Plexus keyboard, they may be accessed from an external keyboard by sending the correct MIDI
Notes on the correct MIDI Channels to MIDI IN.
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 9
Untuned Output Mode
The Tonal Plexus keyboard normally sends tuned output corresponding to MIDI Note and Pitch Bend
data stored in a Tuning Table; however, when the top panel TUNED OUTPUT switch is set to OFF,
the raw MIDI Note and Channel data shown above is sent to MIDI OUT. This data can then be
received by an external processor such as a software sampler to result in retuned output.
Duplicate Keys
In the default Master Tuning, the following pairs of keys are tuned to the same pitch: Channel A 17 &
18, 68 & 69, 104 & Channel B 0. Channel B 35 & 36, 51 & 52, 87 & 88. These are the keys referred
to as duplicate keys in TPXE software, the large blue keys in Figure 2 below. These keys are not
hard-wired as duplicates; custom user tunings can have any key mapped to any pitch.
Figure 2
!" INSTRUMENTS www.h-pi.com · T O N A L P L E X U S T P X 6s/8s · User Manual 10
Loading...