Thank you for bringing this to my attention... that means this modification makes sense with the other version of the EML 101 that has the SEQ input instead of the EXT OSC CONTROL input. Mine has the EXT control jack.

I asked because the guy used a sequencer KORG SQ1 to demonstrate the mod, which is absolutely not necessary in that context of use.

The EML uses non-standard CV scaling, 1.2 V/octave. Of course, any modern MIDI-to-CV converters won't scale up properly.

A sequencer can be very useful to tune any synths from any musical temperament systems.

So I am not sure why you did this modification on the EML-101.