Yamaha DX7 Product Manual - Page 65

60 Fingered Porta This is an abbreviation for "fingered contain varying amounts of overtones (harmonics) in Key Pitch Retain This is one of the two ways the portamento." This is a functional mode of the DX7 addition to the fundamental; the overtones create the portamento or glissando effect can be set when the which is available only when the keyboard is set to unique timbre of a given instrument. In the DX synthe- synthesizer is in the POLY (polyphonic) mode. If you MONO operation. Provided the unit is set to fingered sizers, the carrier often defines the fundamental pitch of play a note or chord and hold down the sustain pedal, portamento, and the portamento time is greater than 0 a voice, but not always; sometimes, due to the effects of then release that note or chord and play any other note (actually greater than 30 for any significant effect), you the modulators, the frequency of the fundamental may or chord, the sustaining pitch(es) from the first note/ will hear portamento only when you continue holding be higher or lower than the set frequency of the carrier. chord will continue to sustain at their original pitches. At down one key and then press and release another key Pressing one key at a time will produce no portamento. FM An abbreviation; see "Frequency Modulation." Harmonics These are integer multiples of a fundamental frequency The "first harmonic" is the fundamental. The second harmonic is twice the fundamental, and so the same time, the most recently played note or chord will begin at the pitch of the sustaining note/chord, and will then slide up or down to the proper pitch(es). Frequency Modulation When the output level of one waveform is made to vary in frequency by a circuit which combines it with a second waveform, the resulting complex waveform is said to be the result of frequency modulation. This is not the simple mixing of two frequencies, but rather it is a process which results in the creation of sum and difference frequencies (the fundamental plus the modulating frequency, the fundamental plus twice the modulation frequency and so forth, and the fundamental minus the modulating frequency and so forth). Some of these "sidebands" theoretically extend below 0 Hz, which is actually impossible in an analog synthesizer. However, the FM digital synthesizer correctly follows the equation for FM by "reflecting" the negative frequency components back into the positive frequency domain, but with their phase shifted 180 degrees. In some cases, these "reflected" components will subtract from the level of the fundamental or certain harmonics. Therfore, frequency modulation not only creates side frequencies, it also changes the balance between the fundamental, harmonics and subharmonics. This is one reason why FM synthesis can create such interesting harmonic structures. In the DX7, all the various, complex waveforms are created by means of frequency modulation with sine waves. FUNCTION mode This is a mode of operation wherein the overall performance parameters of the instrument are programmed, such as polyphonic or monophonic operation, or modulation from the modulation wheel, after touch, breath conroller and foot controller. FUNCTION mode is also used to tune the keyboard, to check the backup battery condition, to save or load voices from a RAM cartridge, and so forth. Fundamental This is the basic pitch of a musical note. A note consisting only of the fundamental is a "pure" tone, a sine wave. Most instruments play notes that also forth. Harmonics are similar to overtones, except the first overtone is the second harmonic. In the DX synthesizers, harmonics are generally created by the interaction of the modulator(s) with the carrier(s), although parallel carriers set at integer multiples can also produce harmonics. Hz This is an abbreviation for "Hertz," the unit of measurement for frequency 1 Hz is equal to one cycle per second (1 cps). INIT This is an abbreviation for "initialize." In the DX synthesizers, there is no such thing as erasing a voice memory. The memory including the editing buffer, will always contain some data... some numbers that describe a voice. If all data were set to zero, you would hear nothing, and it would take a lot of programming to get any sound at all. Therefore, when you INITialize the buffer memory or the entire RAM cartridge (which you can do with the [CART FORM] button in FUNCTION mode), the DX7 stores a very simple, basic voice in the memory This voice has all "square" envelopes (all rates and levels at 99 except level 4, which is 0 - operator 1 output level at 99 and all others at 0 - all frequency ratios at 1.00 - all modulation and other parameters set to 0 or minimum value). INT This is an abbreviation for "internal," as in "internal voice". The DX7 has two primary places to store voices, in the cartridges or in its internal memory The LCD display often abbreviates the source of an internal voice as "INT." Key Pitch Follow This is one of the two ways the portamento or glissando effect can be set when the synthesizer is in the POLY (polyphonic) mode. If you play a note or chord and hold down the sustain pedal, then release that note or chord and play any other note or chord, the sustaining pitch(es) from the first note/ chord will slide up or down to the most recently played note/chord. kHz An abbreviation for "kiloHertz," or 1,000 Hz. LCD This is an abbreviation for "liquid crystal display." This is the type of display technology used to indicate the name of selected edit parameters, functions and voices on the DX7. Liquid crystal displays operate by means of special chemicals which change their light polarization characteristics when voltage is applied to them. In combination with a constant polarized layer, the voltage-altered crystal cancels out the light completely forming the black dots which create the alphabetical and numerical symbols in the display. You can test this effect by looking at the LCD with polaroid sunglasses - at a certain angle, the display will be completely black. LCD displays do have a limited viewing angle due to the effect of light polarization, and at very high or very low temperatures they may not function correctly However, they are reliable, quite visible in bright light, and they use very little power (making them popular for wristwatches and calculators). LED This is an abbreivaition for "light emitting diode." This is the type of display technology used to indicate the number of the selected internal or cartridge voice on the DX7. Numerical light emitting diode displays actually consist of 7 segments for each number. Voltage applied to the diodes is converted to light, red light in this case. The DX7 LEDs are very visible in low light levels and can be viewed over a wide angle. LFO This is an abbreviation for "low frequency oscillator." Like the sine wave "oscillators" in the operators, the LFO in the DX7 is actually a digital oscillator. However, it can be set to create a square wave, a triangle wave, an upward moving sawtooth, a downward moving sawtooth, or a sample-and-hold wave (random output) as well as a sine wave. The LFO output can be varied in "speed" over a range from under 1 Hz to about 50 Hz. The LFO can be assigned to vary the amplitude of individual operators, or the pitch of the entire voice.