McGary Audio

Thursday, September 17, 2009

Review! Rotel Home Theater Flagships:
RSP-1570 7.1 Channel Processor/Preamp
RMB-1575 Five-Channel Surround Amplifier

Rotel Matched-Set Refreshingly Easy to Set Up

by John Gatski
Since the early 1960s, Rotel hi-fi products have been a contender in the quality sound/good pricing arena. I remember Rotel’s 1980s receivers, entry-level audiophile RP turntables, and, later, the CD players and home theater gear — all have been successful in the marketplace.
Building on its sonics/price heritage comes two very nice, home theater products, the RP-1570 preamp/processor and the RMB-1575 five-channel amp. Both offer very good performance, and an ease of use and ergonomic simplicity that are much welcome in this age of increasing A/V complexity.

With the high level of audio/video performance now extracted from Blu-ray players the RSP-1570 preamp processor, priced at $2,199 was designed with to bring out that quality in a home cinema system: 7.1 channel audio, 32-bit DSP engine, 24-bit/192 kHz audio converters, Faroudja video engine and plenty of connection options. And considering the complexity of full featured home theater processors, this is one the easiest preamps to use.
Made-in-Rotel's manufacturing plant in China, the RSP-1570 has most features any videophile would want, including 1080P video, 7.1 decoding for all home cinema audio formats (Dolby Tru HD, DTS Master), as well as straight ahead uncompressed PCM. Two-channel hi-fi buffs get analog bypass of the internal processing and video circuitry for a straight analog signal path.
The RSP-1570 will also pass DVD-Audio format soundtracks up to 24-bit, 192 kHz via the HDMI jack, but you have to have one of the rare DVD-A players with HDMI output. Unlike the Integra processors, the RSP-1570 does not relay DSD digital signals via the HDMI input. SACD is decoded via the player and connected to the preamp analog inputs.
The Rotel processor/preamp is programmed with numerous DSP modes to enhance surround, normal stereo and mono soundtracks. Digital SPDIF inputs allows PCM audio to feed the preamp for 24-bit stereo audio up to 96 kHz. The HDMI input also accepts these digital signals, as well as the previously mentioned surround formats.
The Faroudja video engine offers excellent upconversion of DVD video to near HD quality, as well as decoding of true Hi-Def sources up to 1080P. The video processor supports Deep Color as well as 1080P-24 frame video via the HDMI v1.3.
The RSP-1570’s connections options are numerous and can support just about any device you want to connect to it: 7.1 analog inputs, four HDMI inputs, three sets of zone audio and video jacks, tape loop, stereo CD and tuner inputs, four optical and three coaxial digital audio inputs, and coaxial and optical digital outputs.

The processor also maintains compatibility with older A/V components (laserdiscs, VCRS, non-HDMI DVD players) with S-video, composite and component I/Os. An RS-232 ethernet input allows for direct software updates and computer control of the unit. The 12V triggers enable remote powering of the RMB-1575 or other 12V components.
Curiously, unlike the Integra and Onkyo high-end processors, the Rotel does not have any XLR audio inputs/outputs that high-end videophiles often use to connect to high-end balanced amps. Oh well, you can’t have everything. (Rotel says that most competing products with XLR connectors are not truly balanced and the more-economical, unbalanced RCA signal path is quite immune from noise in the typical short runs of home theaters-ED.)
The preamp includes a very nice, easy-to-use, well-lit remote control that allows control of all RSP-1570 functions. There are also front panel controls, including volume, EQ (HF, LF), input switches, stereo and surround mode buttons, and the multichannel analog engage button. The front-panel display is just the right size and LED brightness to make it readable from a dozen feet away.
Deep into the setup menus, there are numerous settings that have to be selected to get your Rotel home theater operational, such as assigning the desired video and audio input to the component, speaker setup, delay, subwoofer crossovers, selecting the desired surround speaker set up (5.1 or 7.1 for example), zone setup, and speaker level/delay/size/selection. Video parameters are easily adjusted via the selected menu, including output screen resolution and input source. Rotel also has a handy setup utility available on its web site.
Priced at $2,799, the RMB-1575 amplifier, made in the same factory, is a Class-D amp that provides exemplary efficiency and low-heat generation, netting 250 watts per five channels, yet consuming only 600 watts of AC at full power with all channels driven. Its features are minimalist: a power switch, five RCA unbalanced input jacks, five sets of WBT-five-way speaker cable binding posts and a 12-volt trigger input/output.
The amp is housed in a attractive silver finish cover (black is available) with an abundance of vent holes (maybe too abundant, considering its heat generation was almost nil under normal operation). Like the RSP-1570, the RMB-1575 has no XLR connectors.
Overall, the RMB-1575 supplies analog amplifier with plenty of drive capability for most any music or home theater speakers. Considering the multichannel power, this Class D amp weighs in at a lightweight of 24 pounds.

The setup
I was excited when I took delivery of the Rotel’s flagship preamp/amp tandem. I had heard from Internet scuttle that the preamp/processor was one of the easiest to use. Indeed, that turned out to be true. The RSP-1570’s easy access menus include Input, Delay, Sub setup, Other, Contour, Speaker, Test Tone, Default Test and Video/HDMI.
The Input function allows you to name the input for easy screen ID, assign the video and audio inputs (multichannel or digital) and adjust parameters — such as attenuation for custom component matching. The Default mode automatically selects a surround format if the source digital surround input is not identified. Group Delay helps correct lip-sync discrepancies inherent in digital audio/video systems; it only works with digital inputs. The LFE Direct allows a mono-summed bass signal — derived from 7.1 channels to be chosen — if desired. This mode is another options for multi-channel analog input bass routing, designed for high-pass speakers. Other setup menus worth noting include the Speaker Setup with its advanced setup sub-menus, such as allowing crossover optimization based on surround format recommendations.
The Subwoofer Setup menu has a very cool feature that allows the user to adjust the subwoofer level for the multichannel analog input — independent of the preamps main output. This feature is quite useful. I have found on other preamps and receivers that the subwoofer levels from a BD player’s analog out often are different than the HDMI outputs. In order to get the system to have consistent levels for multiple sources, the multi-channel input sub level option enables precise adjustments so you don’t have to change the level when switching from analog to digital inputs. Very cool, Rotel.
I placed the Rotel RSP-1570/RMB-1575 combo in my home cinema room utilizing it in a 5.1 multichannel set up with the separate audio processor, five channels of amplification, powered subwoofer and a Sony Bravia XBR4 52-inch LCD with 120 Hz refresh rate. BD players included the reference Pioneer Elite BDP-09FD and a Sony BDP-550. The players were connected via HDMI and analog multichannel analog cables to the Rotel RSP-1570 preamp/ processor.
The preamp output was connected to the Rotel amp, or for comparison purposes, a tandem of 200-wpc USA-made, Carver amplifiers I use for reference (three-channel A753 and the two-channel A500X). The Rotel amp drove a pair of professional Westlake LC8.1 speakers for left and right front channels, a Westlake LC2.65, center channel speaker, and a pair of NHT Ones that were used for the two surround channels. The RSP-1570's subwoofer output was connected to a Paradigm Servo Reference 15.
All player-to-preamp/preamp-to-amp audio interconnections were made with Alpha-Core Goertz solid-silver conductor cables; the speaker cables were provided by MIT. PPC’s Locking HDMI 1.3 cables connected the Sony and Pioneer BDPs to the Rotel and the LCD. For clean AC power, I used a Panamax M-7500 power conditioner and Music Cord premium power cords for all IEC-plug components. Channel levels were matched using my professional Audio-Control RTA-3050 Real Time analyzer/measurement microphone and a Gold-Line home theater test signal DVD.
The RSP-1570 gets quite warm during normal playback, but not overly hot. The Rotel amp ran cool as a cucumber, except when cranked for a long period of time, which it only achieved slightly warm status. The RSP-1570 switches very quickly when selecting different inputs — the sound and the video switch almost instantaneously. Other preamp processors I have used are slow in switching the audio/video — taking 2-3 seconds or more before the input is active.

The audition
I tested the preamp/processor with several sources, including the Sony and Pioneer BD players as well as a Yamaha DVD-S2300 Mk-II universal player with SACD and DVD-Audio playback capability. The Yamaha was linked to the Rotel preamp via Kimber Cable interconnects.
First up was Blu-Ray. I popped in the animated feature — Bolt. I first set up the Rotel for HDMI audio/video input from the Pioneer Elite BDP-09FD. In this configuration, Rotel did all all the DTS Master HD lossless decoding. First impression? dynamic, open, crisp transients with tight deep bass. The opening action sequence gives a surround sound system quite a work out with plenty of panning effects front to rear, sub explosions and highly dynamic music.
The Rotel tandem sounded super. The Transformer and Blackhawk Down Blu-ray discs also showcased the Rotel’s internal-decode surround prowess again with impressive panning and clear intelligible dialogue.

The soundtrack imaging of the Rotel's internally decoded soundtrack was well-placed and defined, but not quite as open when comparing it to the output of the Pioneer BDP’s internal converter, multi-channel analog through the Rotel. There was just a bit more space in the surround sound cues coming from the BD player’s internal converters via the Rotel’s analog inputs. But to be fair, no processor that I have auditioned has matched the Pioneer Elite BDP-09FD’s internal decoding. It is that good.
Overall, the RSP-1570's analog input sound is very good with surround or stereo. Versus an Integra 7.1 preamp I borrowed, the sound was pretty close, although the Integra was slightly warmer and and smoother on transient-heavy pop music, such as big band and jazz music.
My stereo SACDs sounded great through the Yamaha universal player and Rotel’s analog inputs. On the DMP SACD, Steve Davis Quality of Your Silence, the Rotel handled the high-res piano quite well. Elton John’s Tumbleweed Connection SACD, a very well recorded and remastered pop music disc with a nice multitrack airiness, was relayed nicely by the Rotel — with just a slight bit of crispness in the transients.
The RSP-1570’s video processing is outstanding! With Blu-ray at native HD resolutions or DVDs that are upconverted to the desired HF format, the video processing had no artifacts, and I could not tell a difference between the BD players’ HDMI direct feed to the LCD or the RSP-1570’s HDMI video output.
Although priced at nearly $3,000, the RMB-1575 five-channel amplifier is perfect for home cinema use; its powerful, crisp, punchy character — combined with a well-defined imaging — makes for an A/V amp that projects the nuances of soundtrack with out the mushy haze of cheaper receivers and amps. The clarity stays put no matter how loud you play it. Through several audiophile stereo preamps, it lacked the audiophile warmth and ultimate openness on stereo tracks, but that is not really its purpose.
There were no real sonic or user complaints with the Rotel duo — other than the omission of balanced inputs/outputs. The Integra and the Onkyo Pre/Pro processors both have them.

The verdict
The RSP-1570 is a high-end preamp that is one of the easiest to set up that I ever used. Couple the ergonomic friendliness with plenty of connectivity and quite good sound quality, and you got a preamp that is recommended for home theater. If you like to stick with the same family, the RMB-1575 amp is a nice mate for the RSP-1570. The preamp, especially, is definitely a Stellar Sound winner!
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