Update

Sunbeam read the original review of the Rheobus Extreme and listened. Since then, they have worked to tweak the Rheobus Extreme and have sent me a newer version to correct the problems I found in the original. To recall the original faults I found during the review:

• Fan connectors along the back edge were all seated differently
• Some of the heatsinks wobbled a lot
• Lower right solder pad missing, and other pads were not holding the heatsinks all the way
• Large voltage drop (as much as 1V off the top end)

The original Rheobus Extreme Sunbeam sent me is on the left, and the newer one is on the right. Since the review I had gone through and straightened all the fan connectors on the original unit by hand, and the new version is just as straight. Also, though it is a little harder to tell from the picture, the large heatsinks are straighter, too, and definitely more secure. All of the "heatsink wobble" of the original unit is now gone.


On the bottom of the unit, the printed circuit board is now covered with a sponge material. This helps to protect the PCB from shorting out and at the same time helps to protect it from damage.


Sunbeam has removed some of the resistors on the power lines. In the original unit on the left, multiple resistors can be seen in each of the red boxes. On the right, the new unit only has one resistor inside each of the red boxes. How this translates into the voltage readings is reflected in the table below.


Surprisingly, Sunbeam has changed the voltage range. The original Rheobus Extreme was rated between 4V and 12V, but the new version is 0V to 12V. I checked the new package and the new manual, but neither of them reflected this change. Then I checked the website, and found that the voltage has been changed in one instance (under "Specifications") but not the other (under "Features").

With the first review sample I found that the voltage dropped nearly one volt (as much as 0.86V to be exact), which I felt was a bit too much. With the latest sample the number is about the same ( as much as 0.92V). However, this time I crunched the numbers and realized that the high-end output is still within the rated specification of 10%, and the voltage probably seems very low due to may aging PC/XT power supply. Also, the output voltage will depend a lot on which fans are used and how much voltage they are supplied. Channel 1 supplied 10.55V with all six fans running at full speed, but that voltage rose to 10.84V when channels 2 through 6 were turned all the way down.