Go to Home Page

Click Here to Go to Index for All Audio Accessory Reviews.

 

Product Review
 

Rotel RLC-1080 AC Line Conditioner and UPS

Part II

September, 2006

Kevin Lichterman

 

Electrical Performance

With respect to electrical performance, I examined the various power backup and conditioning features of the RLC-1080. From the manual, these include Pure Sine Wave Battery Backup, Automatic Voltage Regulation, Surge Protection, and Isolated Noise Filter Banks. For these tests I utilized a dedicated 20 Amp circuit, a Tektronix oscilloscope, two Hoover vacuum cleaners (real nice ones), and a hand mixer. Let's just say I don't think my 'lab' is UL certified.

First of all, I made some reference measurements comparing the power directly from the AC outlet to the power output of the Rotel under normal conditions. Shown in the graph on the left, the orange line reflects the output from the AC outlet and is measuring 124 V (Volts) at a 60 Hz frequency, close to the ideal measurements of 120 V and 60 Hz (guess I'll have to send that check in to the power company this month with a smiley face). The output of the Rotel, in blue, is measuring 122 V and 60 Hz, a slight difference from the input.

References aside, let's take a look at the features. Using layman's terms (which is as much as I can manage) the "Pure Sine Wave Battery Backup" feature of the Rotel means that the power generated in battery or UPS mode will closely emulate the power provided by your power company. If compared side by side, the AC power sine wave from the UPS should be the same. It can be seen in the graph that the output is indeed a sine wave at 60 Hz, slightly flattened at the top (indicates harmonics).

There is a small peak that can be seen in the wave that might be an issue. However, the 60 Volts RMS measured would indicate that the power provide by the Rotel in UPS mode only is lower than when connected to the wall. If power does go out, I'd hesitate cranking things up - high powered ampifiers may be starved for power. To be realistic about the whole thing, you really should just power everything down if your AC supply goes down, and wait for it all to come back again. The battery backup is not really intended for continuing to watch a two hour action film.

Next I took a look at the "Automatic Voltage Regulation" feature. This feature is designed to ensure that no matter what happens to the power coming out of the wall outlet (well from 90 to 140 Volts at least), the voltage provided to your equipment is consistent and within acceptable limits neither too high nor too low. I didn't have the equipment on hand to test the too high portion of this claim, but I could test the too low, and well, I must say, this test sucked.

What I mean is that it took two vacuum cleaners running on the same 20 A circuit to lower the line voltage significantly enough to activate the low voltage protection feature. With both vacuums on, the Rotel detected that the input voltage was lower than acceptable limits and automatically adjusted the voltage to my gear (that and it illuminated a reassuring blue light to let me know all was OK). The blue line in the graph shows that the Rotel did indeed adjust the voltage output adjusted the sagging line voltage of 120 Volts to 127 Volts. I was a little surprised that 120 Volts was the default trip point, because according to the manual, I would expect between 90 and 100 Volts.

Finally, I took a look at the Surge Suppression and Isolated Noise Filter Banks features. Surge Suppression refers to the Rotel's ability to absorb potentially damaging spikes in power from entering and damaging your gear. Noise filtering refers to the ability of the Rotel to remove electromagnetic and radio frequency noise from the power supplied to your equipment, allowing for the best possible reproduction of audio and video. In the case of the Rotel, not only is the input power filtered but the equipment itself is isolated from one another through the use of twointernally separate sets of outlets.

As in the over-voltage test above, I lacked the facilities to fully test either of these features. What I did have on hand was a hand mixer from the kitchen. Electrically, this was the nosiest thing I could find in my house. As can be seen in the spikes in the orange line in the graph, connecting the blender to the circuit caused some measurable noise to be injected into the Rotel. On that same graph, you can see in the blue line that the Rotel removed that injected noise from the line just as promised.

UPS Performance

Although I noted the results of the electrical test of the UPS in the Electrical Performance section, your may be asking, "So how does it work?" In a word, seamlessly. To test the feature I fired up my system and waited for the next thunderstorm to hit . . . and waited . . . and waited. Ok, I really just had someone disconnect the dedicated line to my theater at the circuit panel, but a thunderstorm would have been cooler. As soon as power was disconnected, the Rotel immediately switched to UPS mode. An "On Battery" light illuminated on the display, and a fan kicked in, allowing the equipment to continue without glitch.

How long can you run on battery? It depends on the power needs of your equipment. So to find out, you could either pull out your calculator, or let the Rotel do the work for you. For every piece of equipment connected and turned on, the amount of runtime that will be provided is re-calculated by the Rotel and displayed. In my system with the TiVo on and the rest of my system off or in standby, I got 120 minutes of runtime. With everything on, this drops to 20 minutes. Not bad really. Plenty of time to cool the projector lamp, and if you must, watch the first part of the Pearl Harbor attack scene.

Although not available for my review, the Rotel also provides a path to increase the on battery runtime. An external battery back, the RBB-1080, may be attached via the provided connection on the back of the RLC-1080. I guess you might need this if you want to watch the entire attack scene before shutting down.

Wish List

I lived with the Rotel for a number of months in my system, and while it performed as designed, there are a number of my things that would be on my wish list to truly match my own needs.

  • I wish that the delayed power-up feature were more useful in my system. Let me explain. The delayed power-up feature is controlled by the On/Off button on the front panel. This button controls all the outlets on the back of the Rotel - everything connected is either on or off. Two of the outlets, generally assigned to amplifiers, have a programmable delay from the time the on button is pressed before they turn on. This feature helps to lower the current drawn by the system at power-up (in-rush current) and to reduce audible 'thumps' from your speakers as the system powers up (which potentially could damage a speaker). In my system, I have components that must always be powered on to operate, such as my TiVo. With the Rotel always on to power the TiVo, I am left with two options to control the power-up of the system. Either manually power everything on and off or use an automatic power-on trigged by my preamp. Neither choice is ideal. The manual method is, frankly, annoying, and the triggered method causes a sizeable current in-rush at power-on. This in-rush of current overwhelms the Rotel and triggers its current protection circuit. When this happens, power drops to my TV, causing it to reset. This could be simply solved by allowing the configuration of some of the outlets to be always on.

  • I wish the unit were smaller or at least a different size. This is a big unit, the depth of the Rotel exceeds the maximum depth of my Bell'O equipment rack. To fit the Rotel in, it needed to protrude out the front of my rack. Doing this looked a little silly. Also, having a piece stick out is just asking to get it bumped into and potentially cause a nasty scratch . . . though . . . sniff . . . I'm recovering. Also, even pulled forward, connections in the back are tricky. Perhaps Rotel could re-engineer the piece to save depth at the expense of additional height.

Conclusions

Although I had some changes on my wish list, the Rotel RLC-1080 is an impressive piece of AC line conditioning home theater gear that fills a new niche in the home theater market: to keep the equipment powered on temporarily so that proper shutdown can be manually achieved - just like with computers.
 

- Kevin Lichterman -

Copyright 2006 Secrets of Home Theater & High Fidelity

Go to Table of Contents for this Issue.

Go to Home Page.

 

About Secrets

Register

Terms and Conditions of Use