Yamaha DX7 Product Manual - Page 40

Press this button (Don't confuse it with [EG LEVEL], button 22) Then move this slider upward slowly Just to review the changes you have made, notice that the right hand stack (Operators 3 to 6) are turned off, while Operator 2's output level is now increased to 99. This is the modulator which creates the harmonics And repeatedly play notes until the display shows maximum output level Only the frequency should change in the display 35 From a minimum of 0.50 to a maximum of 31.00. Listen to each ratio. You are changing the entire harmonic structure of t h e sound by changing the frequency of the modulator. However, because the modulator output level is at maximum, the bandwidth of the harmonics is great (there are a lot of very high frequencies caused by a lot of modulation). Musically, most of these sounds are "extreme". You can achieve rather different sounding results by simply reducing the amount ot modulation, as demonstrated in the next step. 6. Press [OPERATOR-OUTPUT LEVEL] and thin move the [DATA ENTRY] slider down to decrease the level from 99 to 69 Then press [OSCILLATORFREQUENCY COARSE] and again try playing notes as you adjust the modulator frequency. If you are familiar with analog synthesizers, you may see a parallel between this sound and that of a sawtooth wave which is going through a filter that has a lot of resonance. In fact you are frequency modulating one sine wave with another sine wave; both are set to the same frequency and the same level. There are no filters involved. 5. Press the [OSCILLATOR-FREQUENCY COARSE] button and play a note while slowly adjusting [DATA ENTRY]. In fact play several notes at each frequency setting, and observe the sound. Then move this slider down and gradually raise it or use the [-1] and [ +1] buttons while playing Make sure OP2 is current And see this Then move this slider down slowly or press the [-1] button Until the display shows this output level