Yamaha DX7 Product Manual - Page 29

24 Algorithms can be programmed to change over time, just as a of the sound you achieve is highly dependent upon the Different arrangements of operators are known as plucked string changes its overtones as the note decays. frequencies and levels you program into the operators "algorithms." An algorithm is something like a "patch" Depending on the selected algorithm, operators can (modulators and carriers). The 32 algorithms available in on a modular synthesizer; it defines the way the opera- be stacked up vertically ("series connected"), arranged the DX7 were selected because they offer a broad spec- tors are interconnected, only instead of using patch side by side ("parallel connected") or both. In the vertical trum of useful programming possibilities. cords, the DX synthesizers digitally switch the operators arrangement, when the output of one operator is con- to make up the various algorithms. The DX7 lets you nected to the input of the next, the result is modulation select among 32 different algorithms. Referring to the - the essence of FM synthesis. By convention, we call ALGORITHM #5 diagrams on the top panel of the synthesizer, the small the operator at the bottom of a vertical stack the "car- Algorithm #5 has 3 carriers and 3 modulators boxes numbered 1-6 are the operators, and each "map" rier", and any operators that are above and which feed pf operators (numbered 1-32) is an algorithm: its input are known as "modulators." By increasing the output level of the modulators) going into a given the ALGORITHM #1 carrier, you increase the number of harmonics present, Algorithm 1 has 2 carriers and 4 modulators extending the bandwidth of the voice (making it more "brilliant"). stack of 3 modulators & 1 carrier The bottom operator of a stack is called a CARRIER. Any operators which are connected to the carrier's inputs are called MODULA- TORS. YOU CANT HEAR A MODULATOR DIRECTLY, but you hear its effect by listening to the carrier's altered (modulated) output. A given operator can be ALGORITHM #I6 Algorithm #16 has 1 carrier and 5 modulators. either a carrier or a modu- lator: the only difference is how it is "connected" in a given algorithm. A given arrangement of OPERATORS is called an ALGORITHM. The available Algorithms are numbered. Illustrated here is Algorithm #1, which happens to have 2 parallel STACKS, one with 2 operators, and the other with 4 operators. The relationship between algorithms and the sound By changing the relative frequencies of each operator, you can change not only the fundamental pitch of the note, but also the frequencies present in the note's harmonic structure. Thus, the timbre of the voice can be precisely controlled. In addition, because each operator has its own envelope, the harmonic structure of a note Most algorithms have multiple carriers and modulators. In one algorithm a given operator may be a carrier, while in the next algorithm it may be a modulator - the only difference is how it is connected. In algorithm #5, for example, there are 3 vertical stacks connected in parallel, and each stack has a single modulator connected to a single carrier. Thus algorithm 5 has an equal number of carriers and modulators (3 of each). In contrast, all 6 operators in algorithm #32 are carriers... there are no modulators, while in algorithm #16 there are 5 modulators and just 1 carrier. As you move from algorithm #32 to #1, there is a greater potential for increased harmonic complexity due to the structure of the algorithm. However, the algorithm alone does not determine the sound. The actual nature ALGORITHM #32 Algorithm #32 has 6 carriers and no modulators.