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Rotel RB-1092ICEpower a Cool Way to Enhance Your Sound       

By Jim Bray
November 27, 2007

There's a better mousetrap being built in the world of audiophile equipment, and you may see it in your audio stand one of these days.

In the world of higher end audio equipment, separate components still rule and all-in-one home theaters in a box are looked upon with disdain. In this heady atmosphere, power amplifiers have meant traditionally that you owned a huge and heavy box that generated enough heat to make your fireplace superfluous.

Thus has it been almost since time immemorial, or at least from the days when amplifiers were invented.  

This is changing as companies such as Bang and Olufsen and Rotel create and utilize an innovation that's dragging the hulking, old tech power amplifier into the 21st century.

The hero of the piece – the better mousetrap – is Bang and Olufsen's ICEpower, a switching power conversion technology the inventors call Intelligent, Compact and Efficient (hence the ICE acronym). ICE modules need little cooling and draw far less power than traditional power amplifiers, without compromising the sound quality.

According to their website, ICEpower is a joint venture between Dr. Karsten Nielsen and Bang & Olufsen, forged in 1999 and based on the results of Dr. Nielsen’s PhD work at the Technical University of Denmark.

ICEpower modules have made possible audio amplifiers such as the series of Class D amps from Rotel, a company that likes to be thought of as "great sound and an affordable price." What "affordable" means depends on the size of your checkbook, but in this case it means stuff that costs quite a bit more than the average stuff you see at Best Buy, but which is still far less expensive than a lot of audiophile equipment out there.

In my experience, Rotel equipment is an excellent compromise between "mainstream" consumer equipment and the stuff that requires you to take out a second mortgage.

I first ran into Rotel back in the 1980's, when their local dealer let me use one of their amps as a reference for a while. I was impressed with the audio quality for the price, something that doesn't seem to have changed much since then.

Rotel RMB-1095More recently, I used a five channel Rotel RMB-1095 amp that cranks out 200 glorious watts into five home theater channels. You can still buy this "traditional" amp; it's about the size and weight of a Mini Cooper and may make the room lights dim for a moment when you turn it on. It sounds great, though, and if you don't trust newfangled gadgets like ICEpower, it would serve you well, while (like its competition in the traditional amplifier market) making you beloved by your local electric company.

But Rotel began unleashing ICEpower onto an appreciative audience a couple of years ago, with its terrific little seven channel RMB-1077 power amplifier. According to Rotel's Michael Bartlett, in an email conversation when I wrote about that amp, "The…amplifier is very efficient and, because of the "power on demand" link back from the output stage to the power supply, when current is needed the circuit can draw it immediately."  What this means, basically, is that the power supply is being turned on and off very quickly as the amplifier operates.

Rotel RMB-1077"The input analog signal is converted into a PWM (digital) signal using patented Controlled Oscillation Modulation (COM) technology," Bartlett told me. "After the power stage, the PWM signal is fed back to the Multivariable Enhanced Cascade Control (MECC) system, which compares the PWM signal with the original input signal and compensates for any differences, thus suppressing the distortion introduced in the power stage."

I won’t dwell on the technology because (to be perfectly honest) I don’t understand it a whit. But I do like the results, at least as Rotel has achieved them. This is real stuff, not vaporware, and it works as advertised.

Rotel's embrace of ICEpower since that first Class D amp has continued  virtually nonstop, and now the company has an entire line of these amps, ranging from the abovementioned seven channel RMB-1077 to the spectacular RB-1091 with its 500 watts into one channel and the brand new RMB-1076, a 6 channel, 100 watt amp designed for custom installations.

Rotel RB-1092 and 1091I haven't tried the RMB-1076 or the 100 watts x 2 RB-1072, but I'm currently using two stereo RB-1092's and a mono RB-1091 amp to create a 500 watt per channel home theater powerhouse that makes me smile giddily every time I even think about firing it up. Each amp is about the size of a VCR, so I've been able to stack all three in the same space taken up formerly by the old five channel RMP-1095, but with the advantage of having two-and-a-half times the power – from amps that run so cool I've had to bring out my old snuggle blanket to keep warm down in the home theater.

Amplifiers such as these aren't cheap (the stereo RMB-1092, for example, retails for about $2500), but considering the glorious sound you get from them, and the newness of the technology, they don't seem overpriced. And of course the technology is trickling down through the consumer electronics market, including into some car audio systems, so it's inevitable that you'll be seeing ICEpower in an increasing number of products over the next few years.

Suits me.

It just goes to show how technology can march on even in areas that traditionally changed very slowly, while giving the companies that exploit it something to differentiate themselves from the herd.

And it sounds great, too!

Jim Bray's columns are available through the TechnoFile Syndicate.

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