User manual

Welcome

KEDITOR PHYSICAL is a physical-modelling editor for your Kurzweil K2700. You describe an object, the modes it rings in, what sets it going, what it is made of and where it is struck, and the app turns that into a real K2700 program, mode by mode. Each mode is a resonating layer tuned by the key, so every note is a little object of its own.

It works with your K2700 connected by USB: each move you make reaches it as you make it, and a finished sound is stored on it with one button. Stored, it plays with no computer attached.

• One panel. Everything about the object is in view: its drawing, its modes, the exciter, the material, the envelope, the filter, the EQ and the space.
• Four exciters. STRIKE and PLUCK, a mallet's pulse; BREATH, a source through a body or a bore; RUB, a friction that holds the modes singing.
• Honest about the instrument. The panel shows what each sound costs in voices and says when a ring asks more than a K2700 resonator can hold.
• 26 objects to start from, and your own models kept in the app under their own names.

Getting started

What you need

• A Mac with macOS 12 or later.
• A Kurzweil K2700 and a USB cable to its USB COMPUTER port. MIDI travels on that cable.
• To have the factory objects on the K2700 as programs: KEDITOR PHYSICAL FACTORY.K27, loaded on the K2700 with FILE > LOAD, FILL. It takes free USER IDs and replaces nothing.

First sounds

1. Open KEDITOR PHYSICAL.
2. Play the keyboard at the bottom of the window with the mouse, or any MIDI keyboard connected to the Mac.
3. Pick another object from the LIBRARY, or turn BROWSE.
4. Turn a knob: drag up or down, or use the mouse wheel. Hold Shift for fine steps; double-click most knobs to return them to their default. Its value shows on the status display at the top.
5. Connect the K2700 and press LINK (see Working with the K2700). Press HEAR K2700 and the panel's keys play the K2700.
6. Press STORE when you like what you hear.

The app sounds by itself for trying things out, with HEAR APP. The K2700's own sound is the one that counts: what a program does on the instrument was measured on the instrument, and the app can only come close.

The panel at a glance

The status display

The top line names the program, with the object it started from on the right. The second line shows what a note costs: voices, notes the K2700 can hold at once, and the time the envelope runs for. It takes turns with what you need to know: how many modes are at the K2700's top, and any note from the compiler, such as an AMP that has passed +24 dB. While you turn a knob it shows the knob's value.

Knobs and buttons

• Drag a knob up or down, or use the wheel. Shift is fine. On most knobs a double-click returns the default.
• A button that does nothing for the current object is dimmed. A knob that depends on another says so in its value: GLIDE reads WITH LEGATO, BLOW reads WITH BREATH.
• A button's LED shows that it is on.

The library

• The family buttons narrow the list: ALL, MALLETS, BELLS, SKINS, PLUCKED, WINDS, VOICES, RUBBED and MINE.
• FIND narrows it by name as you type.
• The list. Click a name to load it.
• BROWSE runs through what the list shows. Each one loads at once, and with the LINK on is in the K2700's edit buffer a moment later.
• NAME is the program's name, 16 characters.
• SAVE keeps the model in the app under that name, in MY MODELS. A model of the same name is replaced.
• DELETE removes the chosen one of MY MODELS, after asking.

Your own models appear under MINE, and with a star in the family of the object they started from. Loading another object does not change what you have saved, and does not store anything on the K2700.

The OBJECT display

The display draws the object and, under it, the shape of the selected mode. On a wind it draws the standing wave of the selected harmonic.

POINT

With POINT on, drag the mallet along the object. Each mode is weighed by its shape at that place: a string's harmonics by sin(nπx), a bar's and a tine's by their bending shapes, a membrane's by its Bessel modes. The levels on MODES follow as you drag. A string or a bar goes from the end to the middle, a tine from the clamp, a membrane from the centre to the rim. Plates, bells and bowls are played where they are played, so POINT is dimmed on them.

WAVE

On a breath, WAVE steps through the source:

On a voice, WAVE picks one singer or a choir of three saws a little apart.

The MODES display

The stems

• Drag a stem to move a mode: across for its ratio to the note, snapping to the harmonics, up for its level.
• Double-click to add a mode.
• The buttons under the display choose a mode. + MODE and − MODE add and remove one. 9–16 shows the second page of a body with more than eight modes.

The selected mode

The rings

The lower half shows each mode's ring at C2, C4 or C6: press RING AT to choose. The dashed line is the K2700's ceiling there, the longest a mode of that frequency can ring: 553 / Hz seconds, a little less in the bass. A ring cut by the ceiling shows both what you asked and what the K2700 gives.

How many modes: 8 for a strike, a pluck or a rub, 16 for a body, 7 for a bore, 5 formants for a voice, up to 7. Each mode is one voice for every note; a voice holds two formants a layer.

The exciter: strike, pluck, rub

STRIKE is a mallet: a short pulse through that low pass. PLUCK is the same pulse with the modes falling a further 6 dB an octave of their ratio, as a string let go from a shape.

RUB holds a friction on the object, and its first knob is FRICTION: the friction's low pass. The modes sing while the key is down and ring on when it is let go. The AMP ENV's attack and release are the friction's.

The exciter: breath

How it is played

WIND MAP and FLOW AIR are for a breath through a body; a bore and a voice do without them. On a breath the FILTER is the tone's own filter and the AMP ENV's attack and release are the breath's, so those sections take over the tone's brightness and its start and end.

The voices

On a voice the MATERIAL section is the VOWEL section. A click on A, E, I, O or U chooses the vowel. A Shift-click chooses the second vowel, the one the mod wheel takes the voice to; on the same vowel it removes it.

With AUTO on, the times are set for you when you choose the vowels: a rising diphthong, into a more open vowel, holds its first vowel 40 ms and moves in 120 ms; a falling one holds it 350 ms and moves in 250 ms. The mod wheel still takes the voice to the second vowel.

On MODES a voice has five formants, across by their frequency and with their width on RING. A formant's LEVEL rests, because its level comes from where it is and how wide it is.

Material and size

A material sets every mode's ring by one law, T60 = T(1 kHz) × (f / 1 kHz)^−a, and KEY DECAY to its a. Its LED stays lit while the rings follow it, and goes out when you change a ring by hand.

Body

Space

A K2700 loads a program's aux chains when it enters that program, not when its edit buffer changes. While you are editing with the LINK on, the hall and the delay you hear are those of the program the K2700 is on; the display says whose. STORE with SELECT IT ON THE K2700 puts the K2700 on the stored program, and from there it plays its own.

AMP ENV

Filter

A 2POLE LOWPASS. On a strike, a pluck or a rub it goes on every mode, after its resonator, and at the top of CUTOFF it is off. On a breath it is the tone's own filter, and CUTOFF is the tone's brightness.

EQ and RESPONSE

On a mode the EQ is only a level, since a mode is one frequency, so the app splits each mode's layer into key zones. The zones never sound together and cost no voice. A bore's harmonics work the same way. On a breath through a body the direct sound goes through a real parametric EQ, one voice more unless the object already has that layer. A voice has no EQ. Switching the EQ on or off changes how many layers there are, so the LINK sends the program whole.

RESPONSE draws the filter and the EQ at C4 at full velocity, with a tick where each mode is.

Working with the K2700

LINK

1. Connect the K2700's USB COMPUTER port to the Mac.
2. Press LINK, choose the MIDI port and the channel, and confirm.
3. The LINK's display shows K2700 LINKED and the channel. Press LINK again to go off.

The model goes into the K2700's edit buffer on that channel, and nothing is stored there without STORE. If the K2700 has no PHYS Delay, the app asks before writing it.

Each change sends only what changed: a few parameter messages for most knobs, the whole program when the layers change, and the Info a second later.

If the K2700 is sitting on another program the display reads K2700 ON ANOTHER PROG and your edits stay in the app. Press LINK, or click that display, to send the model there.

HEAR

HEAR APP sounds the panel's keys in the app. HEAR K2700 plays them on the K2700, with the LINK on. ALL OFF, beside the keyboard, lets go of every key held on the panel and of the sustain pedal. All Sound Off, in the app's menu or with Command-period, stops everything.

STORE

1. Press STORE. Give it a name, 16 characters, and a USER ID from 4096 to 8191.
2. Leave SELECT IT ON THE K2700 ticked to put the K2700 on that program afterwards.
3. If the ID holds a program the app says which and asks before replacing it.

The app writes PHYS Delay first if the K2700 lacks it, writes the program, reads it back to check it and tells you so.

READ

Press READ and give a program ID, 1 to 8191. Only a program stored by KEDITOR PHYSICAL opens, because the model travels in the program's Info. A body of more than seven modes takes the rest from the program's own layers.

Playing it: the K2700's controls

A K2700 program hears a controller only if it has a label on its PARAMS page. KEDITOR PHYSICAL writes these labels for you: Reverb Time, Delay Time, Delay Fdbk, and Vowel, Vibrato or Growl where they apply.

The objects

KEDITOR PHYSICAL FACTORY.K27 holds all 26 as K2700 programs, with PHYS Delay. Load it on the K2700 with FILE > LOAD, FILL, and it takes free USER IDs and replaces nothing. Pick any of them on the K2700 and READ puts it in the app.

Troubleshooting