A/B/ab switch where ab has one amp has a isolated ground constant. No leds simpl

[FaithElectronix]

Wanted to convert my old line 6 fbv2 footswitch into an aby switcher without leds and my switches only have 3 posts.

[FaithElectronix]

Also, what size drill bit is needed for 1/4" jacks? I forgot 10 or 11mm?

[bluebunny]

Also, what size drill bit is needed for 1/4" jacks? I forgot 10 or 11mm?

Depends on the jack.  Mine are all 9mm.  But get yourself a step bit, rather than one bit for each hole you anticipate drilling.

[FaithElectronix]

Basically my switches only have 3 prongs and how to make one, without any groundlift.

[mth5044]

If they only have three 'prongs', it sounds like they are SPDT switches. They might also be momentary. You need at least DPDT.