Yes it will work. It is fairly simple to build. You need two jacks, a box and a pot. Google volume box images. They are also available pre-built.
Ampeg uses a 25K audio taper pot for their master volumes. You can use just about any valued pot within reason.
It will work on any Ampeg amp that has a pre out and power amp in.
Official Ampeg Portaflex Club #89
Last edited by beans-on-toast : 08-02-2013 at 10:11 PM.