The pot diameter on both brands I have here is 24 mm, bushing diameter 8 mm.I've used the 24mm .375" bushing Alphas and haven't noticed any real dimensional differences from CTS. The shafts were .25" by .33". Do yours maybe have .25" length threaded bushings? I believe most amp pots are .375". I've never used the 8mm bushing Alphas.
Thanks, I’ll check them out.I normally buy all of my Alpha pots from Valvestorm. They don't give the exact length but they have never come up short on any of my builds with a steel chassis/plexiglass faceplate.
Edit; This store focuses mainly on Marshall circuits so they may not have some of the values needed for other amp brands.