You must have this to roast coffee. I couldn't get enough current to get my hot-air poppers to roast the beans......just batch after batch of baked beans and never a wisp of smoke. One I plugged into the Variac, first crack at 1 1/2 minutes, second crack at 4 1/2 minutes and then beautiful black oily espressor roast!
Negative Product Points
Buy some spare fuses. That small of a fuse in 20 amps is hard to find....you won't find it at ACE or Radio Shack. I've blown a few fuses in the couple of months that I've owned it. I just ordered five more tonight.
I got the 20 amp unit, I think amperage is the key, not voltage. I keep it pegged on 120 volts( but it goes up to 130 volts). I have to have it alone on the circuit. Most home circuits are only 15 amps so it stresses it a little. If I'm using any lights on the same circuit at the same time, the breaker flips. I have a Poppery I "roaster" and it flies on the variac! The steady even current that this provides will even help standard roasters. I've seen reviews on some roasters that the buyer sent them back because they "weren't hot enough". I'm sure if they had been using a variac that wouldn't have been a problem. I have a friend who has a Hearthware I-Roast. I got him to buy a variac and he says it cut his roasting time in half. His roasting results are now much more reproducible. As for me, I simply can't roast without it.
Coffeebeancorral was great. The first one I got had a dent in the side. It still worked fine but they had me ship it back (they paid) and a new one was shipped from the manufacturer. These things are heavy so I'm sure the shipping wasn't inexpensive.
Three Month Followup
A word about the fuses. I think something is wrong with my variac's fuse circuit. Whenever they burned out, the fuse holder was very hot. I think the fuses just melted inside. I never ran the variac over 120 volts. Finally, after I had burned up all of my fuses, I opened the front compartment of the variac. I found the two wires of the circuit running into the fuse holder. I just twisted those two wires together. Of course I also accidentally broke one other solder connection which I had to re-solder. Fortunately it worked. I am now going fuse-less with my variac. Thankfully, its working fine since I have obviously voided any warranty it came with. I figure that if something shorts, my breaker will flip. Incidentally, I bought an I-Roaster which so far works great with the variac. I get very reproduceable results, which is the goal of ownin g a variac.