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Variac Voltage Transformers - Allen Marsalis's Review
Posted: January 1, 2004, 10:30pm
review rating: 7.7
feedback: (0) comments | read | write
Variac Voltage Transformers
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Arrow The Variac Voltage Transformers has 5 Reviews
Arrow The Variac Voltage Transformers has been rated 8.84 overall by our member reviewers
Arrow This product has been in our review database since January 25, 2003.
Arrow Variac Voltage Transformers reviews have been viewed 37,592 times (updated hourly).

Quality Reviews
These are some of the best-written reviews for this product, as judged by our members.
Name Ranking
James Schulman 9.63
Ed Bourgeois 8.50
Allen Marsalis 7.66
Ed Bourgeois 6.50
Matt Romans 6.00

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Ratings and Stats Overall Rating: 8.6
Product Reviewed: AEEC-2090
Manufacturer: KRM Quality: 8
Average Price: Varies Usability: 9
Price Paid: $110.00 Cost vs. Value 9
Where Bought: Coffee Bean Corral Aesthetics 8
Owned for: 2 weeks Overall 9
Writer's Expertise: I love coffee Would Buy Again: Yes
Similar Items Owned:
Bottom Line: Simply put, if you roast coffee at home, you are going to need one of these.
Positive Product Points

- Easy to operate
- Makes home roasting more fun and rewarding
- Fulfills a need at a reasonable price
- Really does the trick!

Negative Product Points

- Not Child proof
- May pose problem for persons with trouble lifting heavy objects
- Industrial in nature (which may be negative or positive to you)
- Adds to the true cost of owning a electric home roaster

Detailed Commentary

I purchased my variac from Coffeebeancoral.com who offers two models, the 590 and the 2090.  The model number is the amperage rating of the product with "90" appended to the end.  That is, the 590 is rated at 5amps and the 2090 is rated at 20 amps.

So what is a variac you might be asking?  Simply put, it is a device that you plug between your wall outlet and your coffee roaster that allows you to control the Voltage flowing in between.  It is like a big volume knob for your coffee roaster!  The variac allows you to step up or step down from 0-130VAC.

The pricing of the two models is such that for twice the price, you get four times the power capacity or so called "rating".  The 590 runs $55 while the 2090 runs $110 plus shipping.  The 2090 has two nice handles that make it easy to manage the larger heavier unit during storage on a shelf or in a cabinet.

Coffeebeancoral.com was very expedient and the product arrived in good condition sooner than I expected since the device is heavy and I chose to ship it "UPS Ground".  But apparently, this company has two points of shipment and my variac arrived the very next day out of Mississippi.  My shipping cost was just under $10, which I though was very reasonable considering the heavy weight of the unit.

Although the unit is "industrial" in nature, I was surprised when it arrived in a retail box.  The box shows the full part number to be "AEEC-2090" and the brand name is "KRM".  I found it interesting that the box listed possible applications - that is, uses for such a device:

- Control Motor Speed
- Control Label Printing Machines
- Physics and Chemistry Lab
- Power Supply Testing
- UPS Testing
- Satellite Equipment Testing
- Rail Road Switching Testing
- Telecommunications Equipment Testing
- High School, College, Vocational School
- University Electronics Lab
- Transformer testing
- Automation Control
- Stage Lighting Control

No mention of Coffee Roasting at all! Now how intimidating does all that sound? No, you do not need a PhD or clearance from the FCC to operate this device!  But you may feel a little more important, and well, scientific than you once did as you roast your next batches!  I must admit that I sort of felt like I was reliving a scientific experiment during an earlier age before chips and keyboards.  Or maybe it felt like I was operating a old model train set with large transformer and big speed dial.

The vendor website goes into good detail on how some roasters that may exceed 5amps draw may still work with the 590 since its specs are written on the conservative side.  However I wanted to stay within factory spec so I went ahead and purchased the larger 2090 model for my Cafe Rosto.

Basically the device is a huge "rheostat" aka "potentiometer" like a volume control on an older stereo amp, only larger.  It operates like a transformer with a movable "center tap" so that voltage can be adjusted by turning a knob.  It reminds me of something that Nikola Teslas might have had in his laboratory.  But don't let it scare you.  It is mounted and protected in a fairly decent enclosure that should keep you safe unless you poke something metal though one of its ventilation slots.  It is very art deco if you ask me, but my wife might disagree and would not want it on display like an artful espresso machine.

If you do by chance drop a knife, screwdriver, or other metal object that lands on or in the unit, play it safe.  Do not touch it.  Unplug the unit from the wall outlet before attempting to remove any metal object resting on or near the variac.  The device is made in China and is industrial in nature.  It is not "child proof" by a long shot! So always remember, "Safety first".  If the unit is not in use and being monitored, unplug it just as you would a hair dryer or other potentially dangerous appliance.

To operate the device is incredibly simple.  Turning the dial to clockwise increases the voltage.  And you can hear the motor inside the roaster increase in pitch accordingly so there is an audible feedback to your hand adjustments while roasting.
Conversely, turning the dial counter-clockwise lowers the Voltage to the roaster, and the roaster's motor decreases RPM's accordingly. There is a power switch on the unit as well.

Now on to the good part, actual roasting!  All I can say is that the unit is superb, probably because the need was so great.  I am now able to control my roast whereas before, I was not.

I was doing all sorts of crazy things in a kluged attempt to control my roast.  Things like cycling my toaster on and off, which sits on the same circuit as the outlet I used for my Cafe Rosto.

This device is a must for anyone roasting using grid power, which varies slightly from home to home across the country.  This is why "one size" doesn't fit all, when it comes to electric coffee roaster factory settings.  We need to be able to adjust the power output of our roasters. I would not have thought that 5 or 10 volts of difference would make such a large difference in my roast but it does.  It may make the difference between a 7-minute roast and a 15-minute roast.

Needless to say, I highly recommend this product for anyone roasting with electricity.  Go ahead and go for the larger 2090 unit.  Who knows, you may end up owning a new roaster someday with different requirements.

A few notes and tips are all that is left for me to discuss.  The unit has a Voltmeter.  And the dial also has a voltage scale printed around it.  However the two readings don't necessarily match.  I would not worry about this. If you stay between 90 and 110 on the dial, you will be fine.  Likewise if you stay within the "green" range on the meter, you will be fine.  Just make small adjustments, clockwise to speed up your roast, and counter clockwise to slow it down.

The website warns of using two high of a voltage, and although the variac is capable of raising the Voltage of a outlet up to 130VAC, this is not recommended for the sake of the roaster and its input Voltage specification which often does not go up that high.  So plan to use this unit as a "down converter" for the most part until you are plagued by particularly low Volage in your area.  But in my case using the Cafe Rosto, what I use as a setting is about 95-100 Volts on the dial for what its worth.  (Your mileage may vary)

Buying Experience

- Great vendor
- Fast Shipping
- A real asset to the coffee community

Three Month Followup

I am pleased to report no problems or issues with my Variac after three months of regular household use.  The Variac is an indispensable addition to my roasting routine and I do not know how I once roasted without owning one.  It is easy for me to laugh at the memory of turning on my  toaster (on the same outlet) to lower the line voltage in order to slow down my roast a little bit.  This was not an "Energy Star" approved solution to say the least!

Unfortunately in the world of home roasting using electric power, "One size fits all" just doesn't work.  Variables such as line Voltage, altitude, humidity, and the moisture content in the green beans demand that we have some control of the roasting process in order to respond to these variables.  A Variac is one solution to this need, and a properly sized unit should last for many years roasting pound after pound with little or no wear or tear.  After all, there is only one moving part (the armature) and once I have found the "sweet spot" around 95VAC, then I hardly ever touch the control knob.

I highly recommend a Variac for control over your roast to speed up or slow down your roast time.  The difference in taste between an 8 minute roast verses a 15 minute roast can be considerable, even if they both result in the same darkness in the end.  Roasting fast leads to a quicker 'first crack" with lots of beans popping almost like popcorn.  A slow roast results in less violent "first crack" and produces a richer darker flavor even if the beans are not actually roasted any darker. If I roast too fast, my wife will tell me that she senses a slight "green taste" and I know that I need to back off on the Voltage on the next batch to produce a longer roast time and a more "well done" bean.  (I swear she has drank one too many Starbucks if you know what I mean.)

There are few simple pleasures in life that match a carefully pulled shot or two of  fresh roasted Arabica from a newly cleaned machine.  If you do not roast your own beans yourself, I hope you are a weekly customer of one of the fine micro-roasters who dedicate their business to serving fresh roasted coffee beans to the discriminating public.  If you do neither, then you are missing out to some extent on what coffee has to offer you.  For me, that is a significant escape - downtime from the fast paced e'life that so many of have grown accustomed to.  My thanks to Coffeegeek.com members for introducing ideas and sharing information so that more people can share in the love of coffee, and help quality coffee bean farmers around the world stay the course.

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review rating: 7.7
Posted: January 1, 2004, 10:30pm
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