do you have a question?
Frequently Asked Questions
Can I connect my computer to my Rotel system for audio?
Yes - if your Rotel product has a back panel input labeled "PC-USB", you can simply connect your computer to this USB input using a standard USB cable. The computer should then recognize the Rotel system as an audio device and you can then play music from your computer through your Rotel system. Do note that you may need to select the speaker as the primary output device for the computer.
- For windows users this can be done by Navigating to Start -> Control Panel -> Sound and Audio devices -> Playback.
- Mac OS X users should navigate to System Preferences -> Sound -> Output.
If you have a Rotel product that does not have a PC-USB input, if your computer has analog or digital audio outputs you could connect your computer to a Rotel receiver or surround processor using one of the analog or digital inputs as you would connect any other source component such as a DVD player or CD player.
Or, for even better sound quality, add a USB DAC to your system such as the RDD-1580. The RDD-1580 features a rear panel PC-USB connection that can be used to connect your computer to the system for high quality audio playback. The DAC would then connect to your Rotel system using the analog output of the DAC into an analog input in the system.
Can I put Rotel components into a rack for custom installation?
Absolutely, Rotel has rack ears available for many of the 15 series products, either included or available as an optional accessory. Talk to your authorized dealer for details on this.
For other Rotel products such as the 12 and discontinued 10 series, rackshelves from manufacturers such as Middle Atlantic are often an alternative. The Middle Atlantic RSH series rack shelves offer custom faceplates to provide a seamless look when using a rack shelf with many Rotel products.
How do Class D amplifiers work?
A Class D amp works by taking the analog input signal and creating a PWM (pulse width modulation) replica of it-essentially a train of pulses, which correspond to the amplitude and frequency of the input signal. In its most basic form, a comparator circuit is used to match the input signal with the PWM signal. The PWM signal is then amplified by an output stage operating in switch mode, which is to say there are two states, on or off, at very high speed, corresponding to the PWM pulses. A linear amplifier's output stages, by comparison, see a continuous waveform and, to avoid distortion, are on for more than half the waveform (Class A/B) or for the complete waveform (Class A), thus greatly reducing efficiency and generating heat.
The amplified PWM waveform is low pass filtered to recover the audio waveform and eliminate spurious ultrasonic noise before outputting it to the speakers. This process seems digital but is in fact analog in nature. The signal is not "digitized", i.e., assigned a numerical value; the PWM pulse train is an "analog" of the input audio signal. What distinguishes Rotel Class D amps from other designs on the market are innovations in the area of generating a highly accurate PWM signal (COM, which stands for Controlled Oscillation Modulation) and in the feedback circuits (MECC, Multivariable Enhanced Cascade Control) to provide a stable filter characteristic in spite of variable loudspeaker impedances. In simple terms, this means that our Class D amps offer full bandwidth performance at very low distortion in "real world" applications-just like our linear amps, but with the benefits of being smaller, cooler and much more energy efficient.
Why aren't there more Class D amps on the market? For starters, creating stable, full bandwidth Class D circuits while controlling RF/EMI byproducts isn't easy. Few companies have the technological know-how to do it. It also requires extensive use of Surface Mount Devices (SMDs), again putting it out of technological grasp of most audio manufacturers. We have invested with a technology partner to realize these designs.
Here's another key detail that often causes confusion. The Switch Mode Power Supply (SMPS) is not what makes these "switching" amplifiers. As just described, the amplification stage is a high speed switching circuit and what defines this design as Class D. A Class D amp could, in fact, use a conventional power supply; and a linear amp could use a SMPS. A traditional power supply stores large amounts of energy, but wastes "excess" energy not demanded by the load in the process. An SMPS matches output to real-time requirements, supplying only the power required by the load, as a result operating very efficiently. The analogy is a water tank (linear supply), which is always being refilled and spills over if demand is insufficient; compared to an endless series of buckets (SMPS), which can be slowed down or sped up as required. The SMPS in our Class D amps reflects the fact that the Class D amplification circuit does not require the massive energy storage of a linear power amp, so the more efficient/compact SMPS is a better choice.
To sum up, our Class D designs offer:
- Excellent audio performance, testified to by numerous critical reviews and awards. Rotel Class D designs are the most advanced in the world.
- High energy efficiency (90%+, compared to 50-60% for Class A/B amps). In our increasingly "green" world, this is an important point.
- Compact size relative to power output.
- Cool running as little energy is wasted as heat.
- Low output impedance translates to high damping factor, or control over the loudspeaker.
- Low impedance load tolerant.
How do I connect my Bluetooth device?
Rotel models with a front USB input will support Bluetooth streaming when the supplied Bluetooth dongle is connected. Models with built-in aptX Bluetooth streaming can skip step 1 as the Bluetooth module is already active.
- Insert the supplied Bluetooth Dongle into the front USB of the Rotel and make sure the front USB input is selected.
- From your mobile device, look for “Rotel Bluetooth” and connect to it.
- Connection is normally automatic, but if prompted for a password, please press “0000” then enter on your device.
NOTE: Not all Bluetooth dongles will operate with the Rotel device. Please use the one supplied. If you do not have the dongle, please contact your local Rotel dealer for assistance obtaining one.
Should I use spades, banana plugs, or bare wire for my speaker cables?
There are several ways you can opt to terminate your speaker wire, depending on what connections your amplifier and speakers have. The easiest and most direct connection is bare wire, but you risk breaking off strands each time the wire is disconnected, or possibly causing damage if opposite stands touch one another or your equipment.
If you expect to be disconnecting and reconnecting your speakers often, perhaps to move them in other locations, you may find banana plugs, spades, or pins more convenient. Most Rotel equipment accepts banana plugs, but not all accept spades or pins. Check with your dealer if you will be using spades or pins.
What brand cables does Rotel recommend?
This is perhaps the most subjective category of all. When you buy a new car, you can look at hard data to aid you in your buying decision. Things like fuel economy, repair history, resale value, crash tests, owner satisfaction, average repair/maintenance costs, and other factual information can prove invaluable. But when it comes to interconnects, it is not as easy.
Rotel does not recommend a particular brand of cable (read: speaker wire) or interconnect for use with its products (there isn't one that's "best"), but we can assist you with some basic pointers. This is really where your local dealer can be very helpful, as they have more experience with using different brands, as well as getting feedback on what their customers have had success with. Of course, what one person thinks sounds best may not be what you think sounds best, so you may want to see whether or not you can get some cables on a "loaner" basis to try out. It is a very crowded field...there are a plethora of cable/interconnect manufacturers, each with their own philosophy on what makes good cable, each having their own price points, and each sounding different from the other.
Cables and interconnects are more important than you might think. If you were to remove all of them from your system, it would be rendered useless. Typically, those that come boxed with the components you buy are quite basic, intended for people who haven't any cables at all. These should be treated the same way you treat that spare "donut" tire in your vehicle's trunk... it does the job temporarily until you can get a new tire on. And when you put that new tire on, you notice the ride, handling, traction, fuel economy, and noise are much improved. Like new tires, but maybe not quite as dramatic, better interconnects allow you to take full advantage of what your equipment can do.
Generally speaking, you should keep your cable/interconnect runs as short as practically possible. Speaker cable should be the same length to each speaker and at least 16 gauge. They should sport durable jackets, be well shielded, and employ high purity copper. Gold-plated connectors will prevent corrosion. When installing your cables, be sure the connections are snug. Keep power cords away from your interconnects, and separate digital and analog interconnects from each other.
What do you mean by 1U, 2U, 3U etc. in the product specifications?
The "U" stands for "Unit Height" and is a standard 1.75" throughout the industry. Therefore a 2U component would have a height of 3.5" and so on. By having these standards it allows a custom installer to quickly predict what combination of U height electronics will fit efficiently into a standard rack.
What is bi-amping and bi-wiring?
These two terms are often confused as they both utilize two pairs of speaker cables that are connected to one speaker.
Bi-amping involves the use of two separate amplifiers however, which deliver separate voltage and current to the bass drivers and midrange/tweeters. To do this, the speakers must have two pairs of binding posts that can be physically separated, usually by removing connecting wires or a metal bridge. This will separate the bass section from the midrange/tweeter section. There are definite sonic advantages to bi-amping that we can't go into great detail here, but damping factor increases and intermodulation distortion goes down.
Bi-wiring requires the same physical separation of the bass and midrange/tweeter circuitry as bi-amping, however, you are only using one amplifier, so both pairs of cables are attached to the positive and negative binding posts on the receiver or power amplifier. In some cases manufacturers have supplied additional binding posts on the receiver or amplifier to help simplify this type of hook up. Bi-wiring has more subtle performance advantages than bi-amping, but it is also less expensive to do than bi-amping.
What is the warranty length on Rotel components?
The North American warranty periods are listed below. For regions outside of North America, please contact your local Rotel Distributor for this information.
Amplifiers, Integrated Amplifiers, Preamplifiers, Surround Processors, Tuners, DACs and Receivers: 5 years
CD Players, DVD Players, Line Conditioners and Cooling Fan Kit: 2 years
Remote Controls and Keypads: 1 year