Rotel RSP-1068 surround preamplifier-processor
By Robert Deutsch   •   July, 2004 Rotel has been in the audio business for four decades, and they were among the first to recognize the importance of the developing home theater market. The last Rotel surround preamp-processor I reviewed was the RSP-1066, in January 2003, and it was a honey: good-sounding, full-featured, and priced at an affordable $1499.

However, all products that include digital components suffer from the phenomenon of built-in obsolescence, and no manufacturer of such products can afford to rest long on their laurels. For pre-pros, there are always new DSP chips and D/A converters coming down the pipeline, and the folks at Dolby Labs and DTS are always introducing new surround modes. The Rotel RSP-1068 is an evolution of the RSP-1066 that incorporates more advanced digital technology, even more features, and additional refinements of analog circuitry.

Technology and Features
A surround preamplifier-processor has three digital components: A/D converter (for analog sources that are to undergo processing rather than being passed through), DSP chip (for surround and other audio-processing functions), and D/A converter (for producing the analog output). For the RSP-1068, all three components have been significantly upgraded from those used in the RSP-1066. The A/D converters are now 24-bit/96kHz compared to 20/48 in the RSP-1066; the new DSP chip is a 32-bit Cirrus Logic CS49400, replacing the 24-bit CS49326 (a big increase in processing capability); and the new DACs are 24/192, not 24/96.

Less glamorous than the changes in chips but probably at least as important for sound quality is the change in power supply: the EI transformer has been replaced by a toroidal unit with higher output, and there are bigger power-supply capacitors and bigger heatsinks to accommodate the additional current. The circuit boards are made of a high-quality fiberglass that, according to Rotel's Mike Bartlett, is of a grade typically seen in much more expensive products.

On the video side, the RSP-1068 has 100MHz bandwidth component-video switching, which is high enough for HDTV. (The RSP-1066 I reviewed had only 10MHz bandwidth switching, though it was improved to 100MHz in later production.) And new with the RSP-1068 is its ability to convert composite and S-video signals to component video.

The RSP-1066 had a pretty extensive collection of inputs and outputs; the RSP-1068 retains all these and adds a third set of component-video inputs and a Zone 2 composite-video output—and the multichannel input/output now has eight channels rather than seven. The RS-232 connection allows a host of new changes, including discrete volume access for both the main and second zones, discrete power on and off commands for Zone 2, etc. Like the RSP-1066, the RSP-1068 is software-upgradeable.

The power of the RSP-1068's new 32-bit DSP chip permits a great deal of additional flexibility in audio signal processing. The tone controls (which Rotel refers to as equalization) may now be separately adjusted for each channel (except in the multichannel bypass mode, of course). There are also independent crossover adjustments for each channel, independent subwoofer settings for each surround mode, and a wider selection of subwoofer crossover frequencies, as well as user-specified power-on volume, volume-change speed, and maximum volume. Also included is a feature that I've seen only in very high-end pre-pros, and not all of them: all-channel audio delay, which corrects problems with lip-syncing created by the delay of the video signal due to extensive video processing.

The surround modes include the usual Dolby and DTS array, plus the new Dolby Pro Logic IIx for 6.1- and 7.1-channel systems, Rotel's own XS 6.1 and 7.1 surround, and DTS 24/96. In my opinion, the range of surround formats and modes has now reached a level that I can describe only as bewildering; however, the RSP-1068's owner's manual has some of the clearest explanations I've seen of these formats and modes.

Setup
For those experienced in setting up home theater systems, integrating the RSP-1068 into one should not prove too difficult. Conversely, for the individual who has not yet mastered setting the time on a VCR, the process can be daunting in the extreme. So many cables, so many plugs—so many ways to screw up. And then, assuming you've made all the connections correctly, you have to specify the speaker configuration, set levels and delays for each speaker, determine the subwoofer crossover settings and level (which can be different for each surround mode), match up video and audio inputs, set up the default surround modes for each input, adjust the tone controls for fronts, center, and surrounds, and make a host of other settings that may make you wish for the simplicity of 2-channel stereo.

In short, the price of the flexibility you get with a pre-pro like the RSP-1068 is correspondingly more complex setup and operation. What helps in this case is the logical arrangement of the various functions and the well-written owner's manual. (However, I question the decision to place the instructions for setup, including speaker configuration, at the end of the manual. It seems to me that this should be one of the first things to be covered.) For surround processing of digital sources, the decoding is usually automatic, with no override possible. With digital sources for which manual surround selection is possible, I was generally content to use the default modes, but it was good to have alternatives available when the default didn't sound quite right. My home theater system has five speakers rather than six or seven, because a) finding space for the extra speakers would be very difficult in my room, and b) I'm not convinced that the extra speakers would provide a corresponding sonic benefit.

The metamorphosis of the RSP-1066 into the RSP-1068 has brought with it some welcome changes in setup and operational logic. The onscreen display is now available at the component as well as the composite and S-video outputs—very useful. Delay for individual speakers is set simply by entering speaker-to-listener distances rather than the more cumbersome procedure used in the RSP-1066, which involved calculating delay times.

And the RSP-1068 has a new remote control, the RR-1050, which addresses most of the criticisms I had of the RR-969 remote used for the RSP-1066. Input selection is now controlled by buttons in the main part of the remote rather than by ones hidden under a sliding panel. (But the important EQ and manual Surround Mode selection buttons are still hidden—maybe the next Rotel remote will correct this.) The RR-1050 can control several other components in addition to the RSP-1068; it's a learning remote with preprogrammed codes for Rotel equipment.

One operational quirk is that when a source has been selected, the remote switches over to control the operation of the selected component. If you then want to control the RSP-1068 (which I would expect to be the default mode), you have to press the Audio button. One highly welcome change with the RR-1050 is that Mute (located just below the Volume Down control, where it belongs) can now be overridden by pressing Volume Up, rather than only by pressing the Mute button again, as was the case with the RR-969. Pressing a switch on the side of the remote illuminates most of the buttons, but only when there's very little ambient light, thanks to a light sensor—nifty.