Yamaha DX7 Product Manual - Page 41

36 7. To compare what the sound is like with and without modulation, you don't have to turn down the output level of operator 2; you can simply turn it off. Press [OPERATOR ON/OFF 2] to turn off the modulator, And again adjust [DATA ENTRY] to hear the results of different frequency ratios as you play play a few notes, then press the button again to turn the modulation back on. Then move [DATA ENTRY] while playing a note (or several) Leave Operator 2 set to a frequency ratio of 2.00 And see the display change from this Listen and watch the display as the ratio changes from a minimum of 0.50 to a maximum of 31.00 The sound you now hear will be simitar to that of a square wave in a conventional synthesizer. In this case, it is created by sine wave modulation of the carrier by another sine wave at twice the frequency, and at a somewhat lower level than the carrier. This is the modulator which creates the harmonics Note that the current operator has automatically switched to OP1; remember it can only be set to an operator that is on. And see the display change to this Note the current operator stays at OP1. If you again want to adjust any parameters for Operator 2, you will have to press the [OPERATOR SELECT] button. In this case, the effect you get as you move [DATA ENTRY] is similar to sweeping a high pass filter in an analog synthesizer. You're not moving a filter, of course, but instead you are controlling the entire harmonic structure of the note by changing the carrier frequency relative to a particular modulator frequency. 8. Now lets see what happens when we leave the modu- lator (Operator 2) set at a frequency ratio of 2.00, and change the frequency ratio of the carrier (Operator 1). Since the current operator automatically switched to OP1 when you turned off OP 2 above, you can just press the [OSCILLATOR-FREQUENCY COARSE] button and play a note while slowly adjusting [DATA ENTRY].