when we exchanged the potentiometer of the EMT JPA 66 we had to come up from 6mm to a 8mm shaft for the poti-knob. At a first action I drilled a larger hole for the knob but I was not really happy because of two points: First of all the knob did not fill the full depth range to the control board. Secondly the material the knob originally was made of I am not really fond of, it is a light plastic one. You might say it doesn’t matter when you touch the knob. No – it does.

This is the Alps poti we built in:

and this is the 8mm knob I found. Heavy and good material to touch. It comes with a serious High End feeling (believe me: the touch and handling feeling is quite important for a High End unit). Sometimes the haptics are the buying reason for someone to decide going for it.
In this case it is the other way round 😉

Never change a “vintage design”. Yes, but if you have a chance to see and feel the difference you will accept quickly.

I like the combination and enjoy turning the knob every time I do, also with the same 6mm switching knob on the left side. The knobs with the outer custom grooved black rings match superbly with the EMT design, in cosmetic & grip.