Hi. I'm searching for locking tuners for my PRS SE Singlecut and came across these Schaller machine heads:


There are 2 options, the screw ins and ones with no screws but a pin. Is the pin a fit for guitars that have a mechanism for it or do they fit universal guitars without the need for drilling new holes to attach to the headstock ?

And any recommendations would be welcome, preferably with the easiest installation possible !

By the way, are there issues with the Planet Waves Auto Trim tuners when you want to de-tune from standard to drop D and further, due to the excess string being cut ?