I was speaking of the plugin.For example, WTF are you talking about with the "original five years ago"?
[edit: I wrote wrong algo 1, I meant 32 although you can use algo any where they are both carriers]A change of 0.025 (which in pratice is much less because it is 0.025 of the index on the left) produces basically inaudible results
Using Algo 32, turn off all operators except one and two.
Leave OP1 at 1 and set OP2 at 1.01 (you will need to use something other than Arturia)
Using C3, as you change from 1:1 to 1:1.01 you will hear a reinforced sine take on a beat frequency. Changing to 1.02 pretty well doubles that beat frequency. The difference is very audible and if you move from C3 to C2 you will notice the beat frequency 1:1.02 move down to C2 to give roughly the same result as C3 at 1:1.01 We use such a change to move our BFO up and down the keyboard as preferred by our choice of register.
Using an oscilloscope and you can see and hear the stark difference between 1:1, 1:1.01, 1:1.02
The engineers at Yamaha were neither stupid nor pedantic. They had good reason to use such fine detail.
Now I first used a DX7 in 1986 and my ears have taken a beating since I started playing in 1968 but I can still easily hear that difference.