Surround Sound Preamplifier/Processor
Rotel,
a company with a history of making quality audiophile products for the
consumer electronics industry, recently introduced their latest digital
surround processor, the RSP-976. The design looks simple, yet strives
to fulfill the sonic quality audiophiles demand in today's new digital
products. Capable of DTS, Dolby Digital and Dolby Prologic decoding, the
RSP-976 is designed to mate with virtually all audio and home theater
products. A total of eight components can be connected to the unit with
up to five of those being video products. This preamplifier supports two
independent zones and is fairly simple to set up even without the user's
manual, which by the way is very well written.
The front panel has a large knob that controls the volume, while two smaller knobs control the bass and treble levels. The bass control varies ± 8 dB at 100Hz and the treble control varies ± 8 dB at 10kHz. A dedicated button for each component on the front panel makes switching between different source material simple and fast. Additional buttons are used for controlling two and three channel stereo, Prologic, 5.1 analog inputs, dynamic range, and record select. Zone 2 can also be controlled with either the front panel buttons or the optional external IR sensor when using the remote control. The front panel LED flashes to let the user know Zone 2 is still active when the unit is placed in the Standby mode.
The
rear panel is loaded with plenty of goodies including discrete 5.1 inputs
for support of the more recent DVD-Audio and multi-channel SACD. The two
channel audio-only inputs have predefined names labeled CD, Tuner, and
Tape. However, the names for the five audio/video inputs can be customized
by the user, making it easier to identify each component. The on-screen
System Status displays the current component, listening mode, record
output, input selection (analog or digital) and the current volume level.
The normal display mode includes the current component, listening mode,
and input selection. This on-screen display data has some limitations
on the video outputs. The composite output displays the status of any
input, but the s-video output is limited to only video components with
active s-video signals at the input. The component outputs do not display
any on-screen information at all. Three dedicated audio-only inputs are
provided as well as five audio/video inputs that include composite and
s-video. A pair of component video inputs is also available, but is limited
to 480i video. Five digital audio inputs are available, two being optical
and the remaining three coaxial. There is also one optical and one coaxial
digital output. The RSP-976 has the ability to be controlled by a computer
or automated controller using basically the same operating codes available
on the remote control. A standard RJ-45 ethernet-style modular plug is
used to communicate with the unit. There is also a Zone 2 remote input
that only controls the Zone 2 functions in the RSP-976. The user can have
exclusive Zone 2 control when an IR sensor is connected to this input
from the zone 2 location. In addition, there are two IR outputs and two
12-volt triggers for controlling amplifiers or other similar devices.
The
internals of the RSP-976 consists of four boards joined together by bundles
of wires. We would have preferred to see ribbon cables used here instead
of loose wires. In my opinion, performance tends to be more consistent
with ribbon cables. The lower board holds the power supply electronics
along with composite video switching and some of the line level audio.
The large digital board shown in the right of the picture performs most
of the digital processing. The smaller board just to the left of the digital
board holds the video switching for s-video and component video. The top
board contains more line level audio along with IR and remote connections.
A robust power supply is designed in this unit to maintain the best sound quality. Low ESR (Effective Series Resistance) capacitors are used to minimize the effective impedance of the filter capacitors and keep the power supply ripple low for maximum performance even during peak demands. The RSP-976 uses the Crystal Semiconductor CS492604 DTS/DD Multi-Channel Audio Decoder for all surround processing. AKM Semiconductors are located throughout the unit for data conversion, including the front-end analog-to-digital and back-end digital-to-analog conversion. Two-channel analog inputs are 64 times over-sampled using the AK5351 dual 20-bit A/D converters. A trio of AK4324 24-bit/96KHz stereo DACs is used for the 5.1 channels. Video switching makes use of the same Toshiba TC9163AN chips used in the $3500 Parasound AVC-2500u we recently reviewed. These devices perform well with 480i video signals, but have an upper bandwidth limitation at around 10MHz. Therefore; they are not suitable for 480p nor either of the high-definition video rates running at 720p or 1080i. An interesting observation was made with respect to the implementation of the video switching chips. In more than one place, video switching chips were mounted on smaller boards stacked on top of one another. This approach can be beneficial since the power pins are common and it takes less space on the main board.
The
RR-969 Universal remote included with the preamplifier is one of the best
we've seen. The body is made from a material that grips well to your hand
to prevent slipping. Each time a button is pressed a beep can be heard
to acknowledge the command. The bottom of the remote has a panel that
slides down exposing even more buttons. Custom programming makes this
remote very user friendly once it's set up properly. Zone 2 can be controlled
with this same remote and once an IR receiver is properly setup, the user
will have full control of the system using the RR-969 remote in the Zone
2 location.
Up to nine other components can be controlled by the remote. Since this remote is fully programmable, each key has the ability to learn a command from an existing remote. The RR-969's integrated clock is a nice feature that comes in handy. The back-light works well and provides easy reading of the buttons in a low-light environment. However, the lower section of the remote under the sliding panel does not light up.
Our review system consisted of three M&K S150THX front speakers and two M&K SS250 Tripoles® for the rear channels. A pair of M&K MX-350THX subwoofers handled bass. The speaker setup menu included the usual small or large speaker configurations as well as the delay settings for the center and each surround channel. We used the small setting and let the subs take care of the rest. All channel levels can be set independently, as one would expect. A nice feature of this unit is the ability to set the subwoofer level differently for DTS, Dolby Digital, Stereo and Music modes. Typically movies have a slightly higher level of bass in my own environment, so this was a welcome feature. We relied on our Sencore SP295 Audio Analyzer to help us set the channel levels for evaluation.
We evaluated both the Dolby Digital and DTS audio using some of our latest 5.1 material. The audio quality was superb in both formats. Pearl Harbor offered an array of aggressive material, particularly in the surrounds, so we used this disc for a large part of our listening tests. We also reviewed various portions of U-571 and the more recent version of Gone in 60 Seconds. Sound panned seamlessly throughout the room giving us an impressive and realistic experience. The deep bass emanating from our M&K MX-350's really made us feel like we were there. We then moved to some of our favorite DTS 5.1 audio discs including the Boyz II Men's version of Yesterday where their vocals came to life. Then there was Steely Dan's Nineteen. Once again the RSP-976 delivered amazingly clean sound with all the attributes one would expect from a more expensive preamp/processor.
Since our review of this unit was running behind schedule, we decided to include the latest Kenwood Sovereign DV-5900M DVD Audio/Video player as a source. The DVD-Audio capability was particularly interesting to listen to on RSP-976. Bypassing the A/D circuitry allowed us to hear the capabilities of this preamplifier in the most transparent configuration. The performance of the analog 5.1 inputs was excellent. Absolutely no grain or edginess could be heard from our source material that included Fleetwood Mac's Rumours and The Doobie Brothers The Captain and Me. Another impressive DVD-Audio recording is track 2 (Fire) from the new Studio Voodoo disc. This disc includes some fast-paced and rather intense collection of African-style music mixes and the RSP-976 had no problem revealing the qualities of this recording.
At just under $1200, Rotel has proven that you can make a great sounding,
yet affordable and full featured home theater preamp. Receivers are nice,
but in the world of high-end home theater, nobody wants to compromise
sound quality for an all-in-one package. Keeping the amplifier separate
from the preamplifier has clear advantages that usually results in a more
flexible system. After all, space constraints in most receivers greatly
limit the ability to drive difficult loads. Mating this preamp with a
moderately priced amplifier such as the $1199 Rotel RMB-1075, will most
likely give you better sound quality than what we've heard from any $2400
receiver. On the downside, the RSP-976 lacks some new decoding features
such as Dolby Digital Surround EX, DTS-ES 6.1 and Dolby Prologic II decoding,
but for consumers who want to enjoy high quality DTS or Dolby Digital
5.1 material, the RSP-976 delivers. Overall, we thought the RSP-976 performed
exceptionally well especially given the price tag. Rotel's focus on sound
quality shows that they are putting their efforts in the right area.
- Kevin Nakano