Reddit reviews Rumba+ Motherboard Upgrade Rumba Control Board for 3D Printer Triple Extruder Multi Color 3 in 1 Out Diamond Hotend

A RAMPS 1.6* kit would be the cheapest. Best would be something like a Einsy RAMBO* (a board very similar to the one on the Prusa MK3), but that's $120. A good middle of the road solution is the RUMBA+* combined with some stepstick format stepperdrivers. The stock anet uses A4988's*, there's also the option to use DRV8825's* (better resolution, but some people experience resonance related issues) or TMC2130's*. (allows for very silent running) and a screen* (if not included)

In any case, make sure that it has some kind of overcurrent protection. I prefer solutions with blade fuses (also commonly referred to as automotive fuses) It really pays to do some research of your own and to see what you want to get out of a printer. Eventually most A8 frames get converted to other models using the other parts of the kit for the electronics. You should check out the wiki, it contains a couple of good pointers to get you started.

*^(please note that the links provided are meant as illustrations and that I don't necessarily mean to endorse the linked products)

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As stated before, just toss the melzi and/or anet controller. They're fire hazards. And while you're at it, better improve rather than sidegrade.

Have you seen this?