Yamaha DX7 Product Manual - Page 36

RATE] as required so you can use [DATA ENTRY] to adjust Rate 3 to a value of 50. NOTE Ifyou are familiar with ADSR envelope genera- long it takes for the sound to die away. Even though 31 tors, you'll probably see the similarity between this Rate 2 and Level 2 are the next segment programmed envelope and the typical ADSR envelope. However, we in the envelope, the sound is not moving toward have not yet "used" Level 2, and it can significantly Level 2. Instead, because you released the key the alter the situation, asyou' l l now learn. sound moves from Level 1 directly toward Level 4. 6. Press [EG LEVEL] until LEVEL 2 appears in the That's why Rate 4 (the slower rate) applies. display then adjust [DATA ENTRY] for a value of 45. Then press [EG RATE] until RATE 2 appears in the display and adjust [DATA ENTRY] for a value of 50. Play a note and hold the key down for a full minute, then release the note. Remember, what you hear is coming from the same EG settings you had established in Step 6 above. If you could see what happens when you "prematurely" let go of the key. the envelope might look like this. When you play the note, observe how the sound builds to a maximum, then falls to almost nothing, then builds to the intermediate sustain level and stays there until you release the key after which the sound slowly fades. This "double" note is made possible by the 4- segment envelope which, if it were visible, would look something like this: When you play a note, observe how the sound builds to a maximum, then falls to the sustain level at a moderate rate and stays there until you release the key, after which the sound slowly fades. If you could see this new envelope, it would look something like this: *The DX7 envelope rates are internally programmed so that each segment of the envelope behaves similarly. A level of 99, whether it is LEVEL I , 2, 3 or 4, is always the same. However, as mentionned in the preceeding text, when a given rate is used for moving from a lower to a higher level, that rate will be faster than if the envelope is moving from a higher to a lower level. This is done because naturally occuring "attack" times are typically faster than "decay" or , "release" times. If all rates were scaled identically you might have to work with the highest numbers for attacks and the lowest numbers for decay or release. Instead, the DX7's "smart" programming lets you maintain a full 100 step resolution within the range you need it. This explains why even though Rate 1 and Rate 4 are both 25 in this case. Rate 1 is faster; it is an upward moving rate. 7. At this point, you're ready to see one more "fine point" about how the envelope functions. We showed you how Rate 4 adjusts the release of the note as it fades from Level 3 (the sustain level) to Level 4 (the final level) which was set at zero. In fact. Rate 4 sets the release time from whatever level the envelope has achieved at the instant you release the key This may seem a subtle distinction, but you can hear it by experimenting with the envelope you have just created. 8. Hold down the key until the note is well info Level 3 (the sustain level). Then release the key, and listen to the length of time it takes for the sound to decay Play several more notes, and compare that time to the rather short time it takes for the sound to fall from the initial peak at Level 1 to the low point at Level 2. The difference is because Rate 2 is 50, which is considerably faster than Rate 4, which is 25. 9. Now play a note and let go of the key just as the sound reaches the first peak at Level 1. Notice how Learning to change the operator FREQUENCY settings The frequency of the sine wave produced by each operator can be set so it follows the keyboard. This characteristic is set with the [OSCILLATOR-MODE/ SYNC] button, and is called "Frequency Ratio" mode because the frequency produced when you play a key is not necessarily tuned to the pitch of that key; it can be multiplied by almost any number you wish by using the [OSCILLATOR-FREQUENCY COARSE] and [OSCILLATOR-FREQUENCY FINE] adjustments to reprogram the operator. For most voices, the DX7 is set to this ratio mode. (The Voice Intialize function also-sets the DX7 to ratio mode.) The frequency does not have to follow the keyboard, however. Instead, it can be set to a single frequency that does not change regardless of which key you play. The "REFS WHISTL" voice of the "Master Group" on the #3 DX7 VOICE ROM uses this "Fixed Frequency" mode. While you can adjust the frequency characteristics of operator 1 (fixed/ratio mode and actual frequency) using the envelope you just created, we recommend changing the envelope. The sustain level (Level 3) is now at 80, and if you hold down a key to experiment with the frequency settings, you will not hear it at full volume.