Tides v2 Different Frequencies Mode - Shift Voltages

I am adapting a chord sequencer on the Teletype for the Tides v2 in Different Frequencies mode and wonder what the logic behind the voltages is that need to be sent to the Shift jack in order to select the different chord structures? I figured out the values, but wonder if there is a formula that I can use instead of creating a lookup table. Many thanks in advance for the help!

parameter = knob + attenuverter * CV / 8.3

Where knob goes from 0.0 (CCW) to 1.0 (CW), and attenuverter -1.0 (CCW) to +1.0 (CW) and 8.3 is +/- 3%. Then parameter is clamped between 0.0 and 1.0 ; and is used to look up an entry in a table with the 21 ratios.

So assuming you have the attenuverter fully CW, and the knob fully CCW, you’ll change a chord for each increment of 21 / 8.3 = 0.4V.


Thank you so much for the quick reply Émilie, this information is super helpful!