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Equipment Review

October 1999

Yamaha RP-U100 Receiver

by James Causey


Review Summary
Sound Definite improvement over most computer sound systems, but doesn't live up to audiophile standards for music-only reproduction.
Features USB port allows extensive software control; includes ability to mix sound from tuner or AUX input with the sounds generated by the computer; small, attractive and easy to use.
Use Be sure to install the drivers before the application software and disregard the descriptions given for the drivers in the owner’s manual.
Value A convergence product that may be difficult to justify when compared to cheaper computer-sound options, although its good looks and coolness factor may be enough for some people.

In the modern world of computing, most users take the ability to watch and listen to multimedia content for granted. Many of them don’t remember the days when most desktop computers (IBM compatibles, anyway) had no sound other than what they could produce from a tiny onboard speaker. In those days, we had to walk uphill for miles in the snow with no shoes just to get a bleep or a blip from our computers -- and we liked it! Of course, more erudite people simply used a computer from competitors like Apple and Commodore to get better sound, but we won’t even go there!

All this began to change in the early 1990s, when enterprising companies like Roland, Adlib and Creative Labs began producing add-on sound cards for PCs that provided multiple voices of digital music and effects. Suddenly, IBM PC compatibles became the premier platform for computer games. However, no one would mistake the sounds produced by those early sound cards as being particularly realistic, and the quality of the powered speakers used with most of these systems was equally poor.

Within the past couple of years, however, there has been a major revolution in computer sound quality. Sound cards have begun to sport decent-quality MIDI instruments, engines capable of decoding high-quality digital samples, and on-board amplifiers that can produce sound that doesn’t make the listener flee from the room. A number of new music technologies have sprung up to take advantage of this improved hardware, including the new-media darling MPEG Audio Layer 3 (MP3), a compressed music format that claims "CD-like quality" at high bit rates. Additionally, many computer games sport surround sound and detailed music and effect tracks; many people also use their computers’ DVD-ROM drives to view DVD-Video content.

The new high-quality formats now available to computer users provide sound quality beyond that which can be reproduced by cheap op-amps and $19.99 powered speakers. Yamaha hopes to provide audiophiles with a new way to enjoy the audio content produced by their computers with the new RP-U100, a device that Yamaha calls a "Personal Receiver."

"Personal Receiver" defined

The RP-U100 is a merger of that consumer-electronics mainstay, the receiver, with technologies normally found only in multimedia computer systems. The idea is to bridge the gap between the two, and provide the basis for a quality computer-audio experience. Yamaha considers the RP-U100 a computer accessory suitable for nearfield listening. As they have pointed out, they make other products for home-theater and audio-only use.

First, as you might expect, the RP-U100 combines an AM/FM tuner with two channels of amplification. It is rated to deliver 30Wpc and has a specified frequency response of 20Hz-20kHz with 6 ohms nominal impedance. The RP-U100 also includes three RCA inputs for external devices (labeled "PC," "AUX1," and "AUX2") and includes a number of DSP effects that attempt to model the soundfield of small clubs, concert halls, and the like. Additionally, the RP-U100 provides "Virtual Dolby Digital," a technique for attempting to reproduce the psychoacoustic effects of a six-speaker AC3 system using DSP effects.

The RP-U100’s PC input, however, is special. Rather than using the RCA connectors, the RP-U100 can also connect directly to the Universal Serial Bus (USB) port on computers so equipped, bypassing and replacing the computer’s sound card entirely. This connection method requires the use of a USB-compliant operating system; right now, the RP-U100 only has driver support for Windows 98, but support for the MacOS is expected soon.

This direct USB connection also provides a number of other features. The application software included with the RP-U100 lets the user access a number of additional features, including selection and modification of DSP parameters, amplifier volume, input, and the selection and naming of FM and AM tuner presets. The RP-U100 can also, much like the AMC 3020 that Greg Smith discussed in his March 1999 "Fringe" column, mix the sound of the currently selected input with the PC sound sent over the USB connector, allowing you to listen to All Things Considered while still hearing the sound effects from a relaxing game of Solitaire.

The RP-U100 carries a suggested retail price of $500, relatively steep for a computer-audio accessory. Even with the combined functionality, is the RP-U100 worth the money?

Associated equipment

Because the RP-U100 is designed to be used with a Windows 98-compatible computer, it spent most of its time in my computer room. My PC is a home-brew system using an Intel Celeron-A 300 overclocked to 450mHz, with 128MB of RAM, a Toshiba DVD-ROM drive, Matrox Millennium G200 AGP video card and 12GB hard drive. This system has a Creative Labs Live! Value sound card connected to a pair of Yamaha YST-M5 powered speakers. The computer and RP-U100 were both connected to an APC Back-UPS Pro 650 uninterruptible power supply for surge protection and line conditioning.

In the computer room, the RP-U100 was used both with a pair of Grado SR-60 headphones connected via the receiver’s headphone jack, and with a pair of B&W CDM2SE loudspeakers on Target stands. Due to the RP-U100’s use of spring-clip speaker connections, I was forced to use a pair of entry-level Monster Cable braided speaker wires, the only ones I had on hand that could be used without stripping off expensive spade or banana connectors.

I also did comparison listening with the RP-U100 in my two-channel audio system to get an idea of its intrinsic sound. The RP-U100 was placed on a granite block, and connected to the B&W CDM2SE speakers using the same Monster Cable wire. My Parasound CD/P-1000 integrated CD player served as the source, connected to the RP-U100 via Kimber HERO interconnects and using an Essential Sound Products A/V Power Flow power cord. All cable and power connections were treated with Caig Labs ProGold (special thanks to SoundStage! Paradise Correspondent Jim Saxon for this tip).


Installing the RP-U100 under Windows 98 was a rather simple affair. You begin with the power off to both the computer and the RP-U100, then connect the included USB cable to one of your PC’s available USB ports and to the RP-U100 itself. Then you power up the receiver and the computer itself, and allow plug-and-play to do its work and hopefully detect the new device. On my system, Windows 98 detected the Yamaha receiver by name, then asked me for the Windows 98 CD so it could install a driver for a "Composite USB Device." This went smoothly, as did the subsequent requests for drivers for a "USB Human Interface Device" and a "USB Audio Device." In all cases, the necessary driver files were found on my Windows 98 CD. When the installation process completed, Windows 98 finished booting and I was greeted with the familiar Windows start-up sound, but from the speakers connected to the RP-U100 rather than through my Creative Labs sound card. The driver installation was complete.

Next, I shut the computer down, and disconnected the USB cable from the RP-U100. The manual strongly insisted this was necessary before installing the application software, a demand reinforced by a large yellow warning sticker on the bag containing the USB cable itself. I rebooted into 98, and popped in the CD-ROM included with the RP-U100. The CD automatically launched an application that walked me through the process of installing the application software used to control the Yamaha receiver; after a few seconds of copying files from the CD, the final installation was complete. One more reboot, this time to safely reconnect the USB cable, and the RP-U100 was ready for use.

Though the installation went flawlessly, I feel compelled to point out two problems with the RP-U100’s owner’s manual. First, the sequence in which the various steps of the installation are presented is somewhat confusing -- it describes the application software installation before the driver installation. The application software will not work properly without the driver installed and the RP-U100 reconnected, and this sequence of instructions could confuse less technically savvy users. Second, in the section of the manual that describes the driver installation, the user is instructed to verify that the drivers have been properly installed by looking in the Windows System Control Panel, in the Device Manager tab. Yamaha’s descriptions of the devices that should appear under "Human Interface Devices," "Sound, video and game controllers," and "Universal Serial Bus controller" are inaccurate. Rather than carrying the specific names listed in the manual ("YAMAHA RP-U100 HID Audio Controls," for instance), each device carries a more generic name, such as "USB Human Interface Device." Even though the receiver appeared to be working properly, these descriptions caused me to try reinstalling the receiver using Yamaha’s CD rather than the Windows 98 CD -- an impossible task, as no actual drivers are included on Yamaha’s CD-ROM. This will definitely cause confusion among less-confident users.


The Yamaha RP-U100 has a cleanly laid out faceplate, with a large weighted volume knob, a power button, buttons to select the current input, and buttons to select the current DSP mode and tuner preset. All of these functions, plus many others, can also be controlled via the application software installed on the host PC, via the USB connection.

When you first launch the RP-U100’s control software, you receive a tiny floating control panel designed to look like the faceplate of the receiver itself. This control panel reflects the current state of the receiver’s selected input, power state, and volume level, all of which can be adjusted. For example, dragging on the volume knob’s pointer controls the receiver’s volume level within an adjustable range, and the change in volume level is simultaneously reflected in the control panel and on the receiver’s LCD display. The same principle works in reverse; if you twist the volume knob on the receiver itself, the pointer on the control panel’s facsimile knob responds in real time. You can even turn the receiver off and on through the same software.

The real power, however, comes in the series of additional dialog boxes and drop-down displays that can be invoked. Clicking a drop-down arrow in the tuner input field brings up a window that allows you to tune to a different station, change bands, or even manipulate presets (you can create, name, and select your own). Clicking the center of the panel’s volume knob allows you to select the receiver’s DSP soundfield (Virtual Dolby Digital, Movie, Live, Game, Hall, Jazz, and Church), and also to adjust the EQ and virtual speaker parameters for each soundfield.

There are a number of different control dialogs that can be invoked, allowing you to modify or adjust nearly all aspects of the receiver’s performance. Though quite pretty, most of the panels are not mentioned or documented in the manual at all, though the online help is rather thorough. Novice computer users or audiophiles might be somewhat overwhelmed by the vast number of configurable options, but this is also the case with any modern A/V receiver, and the presentation of controls through attractive menus actually makes the tasks easier and provides more feedback than through traditional receiver control panels or on-TV user interfaces.


I evaluated the RP-U100’s sound on two levels: first, as a multimedia accessory for a computer, designed to enhance the sound of computer games, DVD movies, and music played on the computer or its CD/DVD-ROM drive itself; second, as a two-channel receiver for audiophile music listening. I chose to do most critical listening with the onboard DSP disabled (set to "Thru" mode), as none of the available soundfields were terribly impressive to my ears. The "Virtual Dolby Digital" mode did a passable job on surround-encoded material, but sacrificed dynamic range and clarity.

The combination of RP-U100 and B&W CDM2SE speakers provided a distinct and meaningful improvement over my computer’s sound card and Yamaha powered speakers. Not only could sound be pushed to a much higher volume level without distortion, music and sound effects both carried significantly more authority, power, depth, and detail.

The WWII tactical war game Close Combat: A Bridge Too Far (developed by Atomic Games, distributed by Microsoft) simulates Operation Market-Garden, in which an Allied airborne force consisting of over three divisions attempted to capture a series of bridges in northwestern Europe to facilitate the advance of Britain’s XXX Corps into Germany. The game includes driving music and digitized voices and sound effects -- in fact, most of the weapon sounds were created by recording the firing of authentic examples (or copies) of the original firearms themselves. On the RP-U100, these sounds became quite striking, making me jump frequently when entering ambushes or discovering previously unknown enemy forces.

An even better test came with Sierra’s Half-Life, a first-person adventure game in which the player takes on the role of a government scientist attempting to fight his way out of a secret research laboratory after an experiment goes horribly wrong. This game relies heavily on the sound system to place sound effects, including gunfire, environmental sounds, the voices of other characters within the game. Again, the RP-U100 provided a dramatic improvement, not only in the clarity and depth of sounds but also with the specific -- and often frighteningly realistic -- placement of sound effects. With my standard multimedia sound, these effects often seemed to come directly from one of the speakers or precisely in between them; the RP-U100, on the other hand, did a superior job of throwing sounds outside the plane of the two speakers, as well as giving a wider range of effect locations between the two B&W speakers.

Music played by the computer was also dramatically improved, whether generated by audio CDs played on the system’s DVD-ROM drive or via MP3 files. Pink Floyd’s The Division Bell [Columbia CK-64200] was distinctly better. Pacing came across more realistically, the dynamic range was dramatically improved, and bass material carried more weight, detail, and punch. Highs were also more clear and distinct. As with the computer games, soundstaging was massively improved as well.

The RP-U100 had the somewhat dubious effect of more clearly revealing the flaws in MP3-encoded material, particularly with tracks encoded at lower bit rates. Tracks that sounded nearly identical to the original CD audio material via my sound card were clearly different via the RP-U100; the changes were more subtle on some materials than on others, and varied widely based on the bit rate and quality of the MP3 codec used. Highs often became tizzier and more spitty, while all aspects of the performance showed certain amounts of smearing and dynamic compression when compared with the original CD.

The RP-U100 fared significantly less well when used in my listening room, perhaps due to the fact that it is meant for nearfield listening -- what you would be doing when using it with your computer. To compare the RP-U100, connected with entry-level Monster Cable, against my McCormack DNA-1 and TLC-1 connected with JPS Labs Ultra Conductor speaker wire, is an inherently unfair comparison, particularly when considering the $3500 price differential. The RP-U100 did, however, exceed my performance expectations; though its sound was somewhat muddy, compressed, and exceedingly dry when compared with my expensive two-channel system, it carried little of the harsh, fatiguing quality normally found in mass-market receivers. Despite its relatively low power rating (30Wpc), it proved capable of producing enough volume from the relatively insensitive (87dB) B&W speakers to satisfy me.

On all musical material, the RP-U100 did far better with simple acoustic instruments than with more complex, layered, or electric/electronic instruments. On Dead Can Dance’s Toward The Within [4AD 45769], the first track, "Rakim," opens with a series of percussion instruments, and gradually escalates into a pounding, rhythmic performance, with a vast array of instruments layered along with Brendan Perry and Lisa Gerrard’s voices. The RP-U100 did a surprisingly good job of reproducing the tinkling percussion of the track’s opening, but completely fell apart as the track’s pace increased. Soundstaging went from impressively realistic to muddied, and instrumental placement went from realistic to a series of blobs located around and between the speakers. At no time, however, did the sometimes-harsh cymbal tones ever edge over into becoming truly fatiguing.


The Yamaha RP-U100 provides me with a difficult dilemma. While it never made me hate listening to music, and certainly never drove me out of the room with harsh or fatiguing assaults to my ears, it didn’t really come up to snuff by audiophile standards. However, I could probably say this for most low-priced mass-market receivers. On the computer, however, which is its intended use, the RP-U100 was a different story. It provided a dramatic and welcome improvement over my low-cost powered speakers and sound card. The tuner was also very handy, and I definitely enjoyed using the included control panels.

What the Yamaha RP-U100’s $500 list price buys you is a gorgeous little device to sit next to your computer, along with a tuner, 30Wpc of amplification, and some nifty software toys to control everything. The B&W CDM2SE speakers and Target stands I used add another $1000 to the system price, for a total of $1500. By comparison, the sound card in my computer cost roughly $130 by itself. Though my current El Cheapo powered speakers, at $40, aren’t terribly impressive, I could easily purchase a similar-quality four-speaker surround-sound multimedia speaker set for not much more, and get real (rather than virtual) surround sound for games and DVD movies. Though the sound on two-channel material would not likely match that of the RP-U100, the surround effects would likely be better than the DSP-generated virtual surround, and I’d have several hundred dollars in my pocket to widen my smile even further. I could also look into buying a good low-priced integrated amp and speakers, the combination of which would cost more than the RP-U100 alone, but would probably give me better sound too. The unique sound-mixing feature of the RP-U100 is quite handy, but is also available in the aforementioned AMC integrated amplifier.

But if you use a computer exclusively in Windows 98 or the MacOS (to take advantage of the USB port, without which you can’t use the majority of the receiver’s features), have a decent set of bookshelf speakers, don’t really care about surround sound, and want to maximize your enjoyment of two-channel CD audio, computer games, and Internet audio files, the RP-U100 might be the receiver for you. When matched up with a pair of giant-killers like the PSB Alpha speakers, the gorgeous little RP-U100 will both look and sound quite nice in your computer system. It also combines your computer with a sound system, saving you space and letting you listen while you work -- or play.

...James Causey

Yamaha RP-U100 Receiver
$500 USD.
Warranty: Two years parts and labor.

Yamaha Electronics Corporation, USA
6660 Orangethorpe Avenue
Buena Park, CA 90620
Phone: (714) 522-9105

Website: www.yamaha.com

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