I'm looking to buy gold colored metal control knobs for Alembic Activators.  Any advice as far as what size or specifics?  Thanks.

There have been two shaft sizes.  Early Epics, Distillates, and Spoilers have a 1/8" shaft size, while all others have a 1/4" shaft size.

If you currently have Hat knobs, you'll need a 1/16" Allen wrench to remove it.

If you currently have Collet knobs, see this page for removal:
http://club.alembicguitars.net/index.php?topic=217.0

Thanks!

If the are new Activators, fine. On older ones (before ~1990) are before Clarostat offered the wave washer so you will get static when you turn a metal knob on those.

The post are all 1/4" shaft on the Activators.

Thanks, yes for the new activators I bought!