It's so much easier to control bead annealing w/a digital controller.
I started out w/a kiln w/an analog controller for lampworking because it was cheaper. It was so much harder to get correct annealing temps w/o a whole bunch of experimentation and it had to be watched constantly just to be sure of retaining correct temp.
W/o any controller at all it would be a difficult thing to reach/keep correct temps for annealing.
If it's fusing, metal clay or something other than lampwork annealing I haven't the experience to comment on difference in type of controller usage.
Here's an article that might answer some questions on controllers
https://www.soulceramics.com/pages/g...ln-controllers
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