Yamaha DX7 II FD User manual

YAMAHA
Voicing Parameter
Reference Guide
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DIGITAL PROGRAMMABLE ALGORITHM SYNTHESIZER
SUPPLEMENTAL BOOKLET

Welcome-----------.,
This is the first in a series of booklets designed to provide a practical guide to creating
your own sounds on the DX7 II. It describes all of the voice and performance parameters,
the range of their values, and the general effect each one has on the final sound. The
parameters are not presented in the order of their physical layout on the front panel.
Instead, they are presented in the order most conducive to understanding FM synthesis.
Section 1 provides a brief introduction to FM synthesis on the DX7 II.
Section 2 describes the basic voice parameters, which determine the actual timbre of each
voice.
Section 3 describes the voice effect parameters, which determine the keyboard and
controller configuration of each voice.
Section 4 describes the performance parameters, which determine such things as the
combination of different voices and the microtuning they will reflect
For continuing information concerning the DX7 II FD!D, consult AfterTouch, the official
publication of the Yamaha Users Group. Many advanced functions will be discussed in its
pages in the coming months. There will also be information regarding the availability of
other materials concerning more advanced applications. To receive a free copy of
AfterTouch every month, send your request to AfterTouch, P.O. Box 7938, Northridge,
CA 91327-7938. On your letter or postcard, be sure to indicate that you are the owner of
a DX7 II FD/D.

Contents
1 Section 1: Introduction
3 Section 2: Basic Voice Parameters
4
Algorithm Button (#7)
6 Output Level Button (#10) Part 1
6
Oscillator Button (#8)
8
EG Button (#9)
11 Pitch EG Button (#13)
13
LFO Button (#12)
16 Sensitivity Button (#11)
17
Output Level Button (#10) Part 2
20
Using the EG COPY Button
21
Section 3: Voice Effect Parameters
22
About Voice Effect Parameters
22
Key Mode Button (#23)
23
Pitch Bend I Portamento Button (#24)
26
BC!MW/AT Button (#25)
29
FC1/FC2 Button (#26)
31
Section 4: Performance Parameters
32
About Performance Parameters
32 Voice Mode Button (#28)
35
Pan Button (#30)
38 FS/CS Button (#27)
40
Micro Tune Button (#29)

Introduction
The DX7 II is a digital synthesizer capable of producing an almost infinite variety of
sounds using a technique of synthesis known as FM (Frequency Modulation).
- 1-

Introduction
The process ofFM synthesis involves the modulation of one oscillator's frequency with
the signal from another oscillator. In the DX7 II, oscillators are known as operators. Those
operators which actually produce an audio output are called carriers. Operators which
modulate the frequency of other operators are called modulators. The overall sound which
results from combining carriers and modulators depends on many factors, including the
specific combination of operators. Another important factor is the output level of each
carrier (which affects the volume ofthe sound) and each modulator (which affects the
timbre of the sound).
The DX7 II incorporates two sound modules, each consisting of six operators. The
operators in each sound module can be combined into 32 different configurations of
carriers and modulators. These configurations, known as algorithms, are depicted on the
front panel of the DX7 II. They determine which operators will act as carriers or
modulators, as well as their specific combination. In the diagrams shown on the front
panel, the operators in the lowest row are carriers. Those appearing above the carriers are
modulators. The lines connecting the operators indicate the signal paths.
The parameters described in the following pages are accessed by pressing the appropriate
button on the front panel. Some buttons display their parameters in several LCD "screens"
which are selected by pressing the button repeatedly until the desired screen is displayed.
The parameter to be edited is selected by positioning the cursor with the cursor keys. The
parameter value is changed using the -11+ 1 keys or the data entry slider.
-2-

Basic Voice Parameters
The basic voice parameters are used to shape the overall character ofa voice. They are
adjusted in the voice edit mode. This mode is entered by pressing one of the VOICE
MODE SELECT buttons from the play mode, selecting the AorB voice with the AlB key,
and pressing the EDIT button. The parameters described below are then accessed by
pressing the appropriate button.
-3-

Algorithm
Button (#7)
Algorithms form the foundation of FM synthesis. They determine which operators will
act as carriers and modulators, the specific arrangement of operators, and the feedback
path (described below). The following diagram represents Algorithm 1, and illustrates the
various parts of any algorithm.
r···;~;~~~;-~-h~;-··1
[ ___ ~esdback loop \
1st Stack 2nd Stack
1 modulator 3 modulators
The Algorithm button (#7) provides access to the following parameters in a single LCD
display.
Alg The Alg (algorithm) parameter selects the algorithm to be used in a voice.
1 Algorithm 1
32
Algorithm 32
Algorithms determine the way in which the operators are combined as carriers and
modulators. This has a fundamental impact on the types of sounds each algorithm can
produce. For example, algorithm 17 creates good flute sounds, and algorithm 32 produces
very good organ sounds.
Fbi Each of the 32 algorithms has one feedback path. The output of one operator (usually a
modulator) is directed back to its own or its modulator's input. The Fbi (feedback level)
parameter adjusts the level of the signal returning along the feedback path.
0 No feedback
7 Maximum feedback
The effect of this self-modulation is not unlike that of modulation by another operator. It
is often applied to string and brass sounds, as well as noise sounds with high level
settings.
-4-

Osc.sync
Transpose
Voice name
Each DX7 II operator produces a sine wave. The Osc.sync (oscillator synchronization)
parameter determines whether or not the sine waves all begin at phase 0. If they do, the
timbre of a voice will evolve in the same way each time a key is pressed.
off Do not start operators' sine waves at phase 0 for each keypress.
on Start operators' sine waves at phase 0 for each keypress.
The following diagram illustrates the effect of this parameter.
:::-· ...... ..
etc. etc.
If this parameter is off, the tonal transition will be smoother between notes played legato
and more abrupt between notes played staccato. This is often effective for acoustic
instruments.
Normally, the pitch of the DX7 II keyboard is set so that the key marked with the small
triangle corresponds to middle C (C3) with a frequency of 262 Hz. The transpose
parameter allows you to shift the pitch of this key (and thus the entire keyboard) for any
voice by half steps to as much as two octaves above or below the standard pitch.
C1 Assign the pitch Cl to the marked key.
C5 Assign the pitch C5 to the marked key.
This parameter is useful for adapting the keyboard range to suit the voice. For example, a
flute or piccolo patch would be well served by transposing the keyboard pitch up. A bass
sound would need a downward transposition.
This parameter lets you name the voice you are editing with up to ten symbols. The
available symbols (letters, numbers, etc.) are printed in brown below the Data Entry,
Voice Mode Select, EG Copy, Performance, and number buttons.
To enter a name, move the cursor to the voice name parameter and hold down the Edit
button, which has the word "Character" printed below it. While holding the Character
button, enter the desired symbols by pressing the respective buttons. Pressing the Internal
button while holding the Character button will produce lower case letters. The Cartridge
button will produce upper case letters.
-5-

Output Level
Button (#10)
Part 1
The Output Level button (#10) provides access to various level and scaling parameters in
two LCD displays. For the moment, only the level parameter itself will be described. The
other parameters control the level scaling of the voice, and will be described later in this
section.
The level parameter is accessed by selecting the normal scaling mode and pressing the
Output Level button once.
Level This parameter determines the output level (amplitude) of the selected operator.
Oscillator
Button (#8)
Mode
Coarse/Fine
0 Operator's output level is 0 (operator is oft).
99 Operator's output level is at maximum.
This parameter is of fundamental importance to FM synthesis. The output level of a
carrier influences the volume of the overall sound. Remember that carriers are operators
which actually produce an audio signal. A modulator's output level influences the timbre
of the overall sound. As the output level of a modulator increases, so do the number and
strength of the harmonics in the sound.
The Oscillator button (#8) provides access to the following parameters in a single LCD
display.
This parameter determines whether or not the pitch of the selected operator will vary as
different keys are pressed.
Ratio Specifies that the selected operator will vary in pitch as different keys are
pressed.
Fi xed Specifies that the pitch of the selected operator will remain unchanged
regardless of the keys being played.
The ratio mode is generally used by carriers to produce different musical notes as
different keys are played. The fixed mode is useful for special effects sounds, and for the
noise component found in many acoustic instrument sounds-such as the breath of a flute
or the plucking of a harpsichord string.
The frequency (pitch) produced by each operator is controlled primarily by the coarse and
fine frequency parameters. The coarse parameter adjusts the pitch of the selected operator
in large increments. The fine parameter performs the same task in small increments. They
are used together to establish a pitch for the selected operator. The coarse parameter's
maximum value is less than the highest possible total frequency value. The fine parameter
is used to increase the total value beyond the maximum coarse value.
-6-

De tune
In fixed mode, the coarse and fine parameters specify the frequency of the operator in
Hertz (Hz). In ratio mode, the frequency of the operator depends on the key being played.
The coarse and fine parameters specify the interval between the operator and the standard
pitch associated with each key. For example, setting the coarse and fine parameters to a
value of 2.00 in ratio mode will cause the operator to sound one octave higher than the
standard pitch level of the keyboard. A setting of 0.50 causes the operator to sound one
octave lower than standard pitch.
Fixed mode values (in Hz)
1. OOOHz Lowest fixed mode value.
1000 Hz Highest coarse value
9772 Hz Highest fixed mode value.
Ratio mode values
0. 50 Operator sounds one octave below standard pitch.
1.00 Operator sounds at standard pitch.
2. 00 Operator sounds one octave above standard pitch.
31.00 Highest coarse value (nearly 5 octaves above standard pitch).
61. 69 Highest ration mode value (nearly 6 octaves above standard pitch}.
Remember that doubling the coarse and fine parameter values raises the pitch of the
operator by one octave. In ratio mode, octaves below and above the standard pitch are
obtained at values of 0.50, 1.00, 2.00, 4.00, 8.00, and so on. The ratio value forming a
fifth with the standard pitch is obtained at 1.50 and the ratio value forming a third with the
standard pitch is obtained at 1.25.
The detune parameter provides a "super fine" frequency control for each operator. It is
used to shift the frequency of an operator by as much as 2 cents up or down (1 cent =
1/lOOth of a semitone). This parameter is independent of the coarse and fine parameters.
-7 Shift operator frequency down 2 cents.
0 Do not shift operator frequency.
+7 Shift operator frequency up 2 cents.
-7-

EG Button (#9)
This parameter has many uses, particularly when simulating acoustic instruments. By
nature, such instruments are never in mathematically perfect tune anyway. Small detune
values increase harmonics, while large values create a chorus effect useful for large
ensemble voices such as brass or strings.
Each operator includes an envelope generator (EG), which allows you to specify how the
operator's output level will vary over time from the moment a key is pressed until after it
is released. This is used to create the envelope or "shape" of a sound.
For example, think of the difference between the sound of a note played by striking a
piano key or bowing on a violin string. The volume of the piano note peaks almost
immediately and decays very slowly until the key is released. The violin sound reaches its
peak more slowly and retains a high level as the bow moves across the string.
Volume
piano
Volume
bowed violin
All acoustic instruments have characteristic envelopes which shape the volume, timbre,
and even the pitch of each note. The EG associated with each operator provides a means
of simulating these envelopes in any DX7 II voice. By controlling an operator's output
level over time, the EG of a carrier affects the shape of the volume envelope of a voice.
The EG of a modulator affects the shape of the timbre envelope of a voice.
-8-

Each operator's EG is specified by four rates and four levels. These parameters are
explained in detail below. The following diagram illustrates the output of a typical EG.
Output
Level
99
Key on
L1
L3
L4
------------------------------------------~Tme
The EG button (#9) provides access to the following envelope parameters in a single LCD
display.
Ll-L4 Each envelope consists of four levels which affect the output level of the selected
operator. These envelope levels are relative to the overall output level specified by the
oscillator level parameter.
0 Level is 0 (silent)
99 Maximum level value
If an EG level is set to 0, the operator with which it is associated will produce no signal
once that level is reached. Once an EG level of 99 is reached, the operator's signal will be
at the amplitude specified by the oscillator output level parameter.
Levell (Ll) is the first level reached after pressing a key. L2 and L3 are intermediate
levels reached while a key is held down. Once L3 is reached, the operator output remains
at this level until the key is released. L4 is reached after the key is released. Since most
sounds fade to silence after a key is released, IA in a carrier EG is almost always set to 0.
The time it takes to reach each of the EG levels is determined by the rates, which are
described below.
The envelope architecture employed by the EGs provides much more flexibility than the
ADSR (Attack-Decay-Sustain-Release) envelopes found on older analog synthesizers. For
example, the volume envelope of a flute cannot be simulated using an ADSR EG.
However, it is a simple matter to simulate such an envelope with the EGs found on the
DX7 II.
-9-

Rl-R4 The time it takes to reach an EG level parameter during the course of a note is determined
by the corresponding rate parameter.
0 Slowest rate (longest time) from one EG level to the next.
99 Fastest rate (shortest time) from one EG level to the next.
Rate 1 (R1) determines the rate at which the operator's level rises from IA of the previous
note (almost always 0) toLl. R2 specifies the rate at which the level move from L1 to L2,
R3 specifies the rate at which the level moves from L2 to L3, and R4 specifies the rate at
which the level moves from L3 to IA after the key has been released.
Used in conjunction with EG levels, rates provide a completely flexible means of creating
various volume and timbre envelopes. These can be used to simulate acoustic instrument
envelopes or to invent new envelopes never before heard.
Rs The first parameter in the EG display is the Rs (rate scaling) parameter. This parameter
determines the extent to which EG rates will speed up as higher notes are played on the
keyboard.
0 EG rates will not be affected by playing higher keys.
7 EG rates will be strongly affected by playing higher keys.
Rate scaling is used to simulate the change in the envelope of higher pitched notes evident
in many acoustic instruments. For example, if you play the lowest and highest notes on a
piano with equal force and hold the keys down, you will notice that the highest note dies
away long before the lowest note. As higher notes are played, the EG rates become faster.
Rate scaling allows you to duplicate this effect in your own DX7 II voices.
-10-

Pitch EG Button
(#13)
Many musical sounds vary in pitch as well as in volume or timbre during the course of a
note. The DX7 II includes a separate envelope generator that is applied to pitch, in
addition to the individual operator level EGs. As with each operator's EG, the pitch EGis
specified by four rates and four levels. These parameters are explained in detail below.
The following diagram illustrates the output of the pitch EG.
Higher
Pitch
Lower
Pitch
99
Note:
Key on
L1
L4
The pitch EG affects only those operators set to the ratio oscillator mode described
with the Oscillator button (#8) above.
The Pitch EG button (#13} provides access to the following pitch envelope parameters in
a single LCD display.
Ll-L4 The level parameters of the pitch EG are very similar to their counterparts in the operator
EGs. The main difference lies in the fact that the pitch EG levels refer to pitch rather than
output level. A pitch level of 50 represents the standard pitch of the instrument
0 Lowest pitch level.
50 Standard pitch level.
99 Highest pitch level.
The difference in pitch between level values of 0 and 99 is determined by the range (Rng)
parameter, which is described below.
Rl-R4 The pitch EG rates are identical in function to the rates found in the operator EGs.
0 Slowest rate (longest time) from one pitch level to the next.
99 Fastest rate (shortest time) from one pitch level to the next.
-11-

When a note is played, its pitch level starts at IA from the last note played. The pitch level
moves to L1 at rate Rl, then to L2 at rate R2, and then to L3 at rate R3. The pitch stays at
L3 until the key is released at which time it moves to IA at rate R4. Unlike the operator
EGs, IA is not necessarily set to 0.
Pitch envelopes can be very effective for a number of voices such as electric bass or
plucked strings. However, it can become difficult to stay in tune with other instruments
when you have set IA to a value other than 50. To avoid this, set the pitch EG rate R4 to 0
or shorten the voice's release time by increasing the R4 rate in the carrier envelope(s).
Rng The Rng (range) parameter determines the difference between the pitch level values 0
and 99.
1I 2oct Maximum pitch difference is 6 semitones (Vz octave).
loct Maximum pitch difference is 1 octave.
2oct Maximum pitch difference is 2 octaves.
Boct Maximum pitch difference is 8 octaves.
Special effect voices often use large pitch range values to produce some rather crazy
sounds.
Vel The Vel (velocity) parameter allows you to control the intensity of the pitch EG's effect
with key velocity. As the keys are played harder (faster), the changes in pitch specified by
the pitch EG become larger.
off Key velocity has no effect on pitch EG.
on Key velocity effects pitch EG.
This parameter gives you very realistic control over "natural" voices such as bass, and can
add a great deal of expression to "synth" voices.
Rs This parameter performs the same function as the operator EG rate scaling. In this case, it
affects the pitch EG. It determines the extent to which the pitch EG rates will speed up as
higher notes are played on the keyboard.
0 Pitch EG rates will not be affected by playing higher keys.
7 Pitch EG rates will be most strongly affected by playing higher keys.
As you play higher notes on the keyboard, the pitch EG rates become faster. Like operator
EG rate scaling, this aids in creating more natural sounding voices.
- 12-

LFO Button
(#12)
Vibrato and tremolo effects are achieved using a low frequency oscillator (LFO). An LFO
generates a slow waveform at a frequency usually well below the range of human hearing.
This waveform is used to modulate the pitch or output level of the operators. For
example, applying LFO to the pitch produces vibrato. Application to operator output
levels produces tremolo (for carriers) or a "wah-wah" effect (for modulators).
The LFO button (#12) provides access to the following LFO parameters in a single LCD
display.
Wave The waveform generated by the LFO is specified with this parameter. The available
waveforms are shown below.
Triangle Wave Square Wave
' '
' '
~·· l·lm·lmlmmr
' :
Sawtooth (down) Wave I Sine Wave
~---
fdb······
Sample and Hold
·~···
The best way to get acquainted with the effect each of these waveforms has on the overall
sound is to try each one after learning how to adjust the LFO parameters. For example,
the triangle or sine waveforms produce the most natural sounding vibrato and tremolo
effects. The sample & hold waveform produces a random signal which can result in some
very unusual effects.
-13-

Speed The speed parameter adjusts the frequency of the LFO.
0 LFO frequency is 0 (LFO oft).
99 Maximum LFO frequency.
Try the entire range of speeds to become familiar with this parameter's effect.
Delay Most acoustic musical sounds do not begin with vibrato or tremolo immediately. These
expressive techniques are usually employed after a certain delay. This parameter allows
you to simulate this by specifying a delay time before the LFO signal is applied.
0 No delay time. LFO is applied from the beginning of each note.
99 Maximum delay time.
Experimentation is the best way to become familiar with the effect of this parameter.
Mode This parameter can also be called the trigger mode. It is used to specify whether you wish
all notes played to respond to the signal from a single LFO or to the signal from their own
individual LFOs.
Si ng1e All notes respond to a single LFO.
Mu 1t i All notes respond to individual LFOs.
The DX7 II includes 16 LFOs, one for each of the 16 notes it can produce simultaneously.
In single mode, the signal of one LFO is applied to all notes regardless of the rhythm or
relationship between them. The LFO is applied to the first note played and all subsequent
notes with the same phase. In multi mode, a separate LFO is invoked and applied to each
note played, so the LFOs on the various notes will not be in phase with each other. This
can be used to achieve uncanny realism in string ensemble voices, particularly with an
adequate LFO delay. Since there is only one set ofLFO parameters to specify on the
DX7 II, the parameter values apply to all LFOs equally.
-14-

Pmd There are two ways to produce vibrato by applying LFO to pitch: "automatic" (LFO is
applied to any played note) and "controlled" (LFO is applied by operating a continuous
controller such as the mod wheel). The PMD (pitch modulation depth) parameter controls
the amplitude or intensity of the LFO signal as it is applied to pitch "automatically." This
parameter acts like an output gain control for the LFO signal routed to modulate the pitch.
(The intensity of "controlled" vibrato is determined by the Pmod parameter, which is
described in the next section.)
0 No LFO is applied automatically to pitch.
99 LFO is applied automatically to pitch at maximum amplitude.
It is largely up to your discretion whether or not a voice should include automatic vibrato.
It depends on the musical context and your playing style.
Amd As with vibrato, the application of LFO to the operator output levels can be "automatic"
or "controlled." The AMD (amplitude modulation depth) parameter controls the
amplitude or intensity of the LFO signal as it is applied to output level "automatically."
As with Pmd, this parameter acts as an output gain control for the LFO signal routed to
modulate the operators' level. (The intensity of "controlled" tremolo or "wah-wah" is
determined by the Amod parameter, which is described in the next section.)
0 No LFO is applied automatically to output level.
99 LFO is applied automatically to output level at maximum amplitude.
As you may recall, application of LFO to the output level of a carrier modulates the
volume of the voice, producing a tremolo effect. Application of LFO to the output level of
a modulator produces a "wah-wah" effect as the timbre of the voice is modulated.
Sync The Sync (key synchronization) parameter performs a function similar to that of the
Osc.sync parameter. In this case, it determines whether or not the waveform produced by
the LFO will begin at phase 0 every time a key is pressed.
off LFO waveform does not start at phase 0 for each keypress.
on LFO waveform starts at phase 0 for each keypress.
Turning the Sync on is useful at slow LFO speeds for producing an identical effect during
the attack of each note. Turning the Sync off produces more natural chorus or rotary
speaker effects, since the LFO cycle is not influenced by the keys being played.
-15-

Sensitivity
Button (#11)
Velocity
The sensitivity parameters provide separate control over the intensity of effect the LFO
and keyboard velocity have on each operator. Following the analogy drawn above, these
parameters act as input gain controls for each individual operator.
The Sensitivity button (#11) provides access to the following parameters in a single LCD
display. The operator to which they apply is selected in the usual manner using the
operator select keys (#1-6).
This parameter controls the effect of key velocity on each operator's output level.
0 Key velocity has no effect on operator's output level.
7 Key velocity has maximum effect on operator's output level.
Setting this parameter to a high value for a carrier will enable you to regulate the voice's
volume by key velocity. Application to a modulator will provide key velocity control over
the voice's timbre.
Ams The Ams (amplitude modulation sensitivity) parameter adjusts the sensitivity of each
operator's output level to the effect of the LFO.
0 Selected operator's output level will not respond to LFO.
7 Selected operator's output level will respond with maximum sensitivity to LFO.
This parameter is used with both "automatic" and "controlled" amplitude modulation.
Pms The Pms (pitch modulation sensitivity) parameter is the exception among the sensitivity
controls in that it affects all operators equally. It provides an input gain control for pitch
modulation in the same way that Ams provides it for amplitude modulation.
0 Pitch will not respond to LFO.
7 Pitch will respond with maximum sensitivity to LFO.
As with Ams, this parameter is used with both "automatic" and "controlled" pitch
modulation.
-16-

Output Level
Button (#10)
Part2
Scaling mode
Now that most of the basic voice parameters have been presented, it is time to finish with
the rest of the output level parameters. In part 1 above, you learned how to adjust the
basic output level of each operator. Other parameters are used to modulate this output
level. The rest of the output level parameters can also be used to modify the output level
of each operator independently.
Pressing the Output level button (#10) toggles between two different LCD displays. The
first screen allows you to select the scaling mode, which is described below. The second
screen depends on which scaling mode you have selected.
The keyboard level scaling mode determines which scaling mode is used to alter the
output level of the operators relative to the range of keys played on the keyboard. This
allows you to change the volume or timbre of a voice in different regions of the keyboard
Keyboard level scaling is extremely important in creating realistic acoustical instrument
voices. For example, consider the piano. The timbre changes as notes of different pitch
are played. In addition, hitting the top and bottom keys with equal force does not produce
sounds of equal volume. These effects can be simulated with keyboard level scaling.
The two scaling modes are described below. Each is accompanied by descriptions of the
parameters which appear in the second LCD display for that mode.
Normal Scaling
The normal scaling mode is illustrated by the diagram on the front panel of the DX7 II. It
is reproduced here for easy reference.
The meaning of this diagram will become evident as you read about the various normal
scaling parameters.
-17-