Luxman F-114 Surround Processor/Amplifier

Luxman has long been noted for doing things a bit differently, and its recently introduced F-114 surround sound processor/amplifier carries on that tradition. Rather than attempt to incorporate everything for the audio requirements of a five-channel "home theater" installation, Luxman has chosen to design the F-114 with owners of existing stereo systems in mind. So if you own a stereo receiver or a stereo integrated amplifier, you need only add the F-114 and three speakers (one center and two rear) to enjoy Dolby Pro-Logic decoding of video movie soundtracks, as well as concert hall, stadium, and simulated stereo effects. Also, one of the three Dolby Pro-Logic modes accommodates those who do not wish to add a center-channel speaker. The F-114 is so configured that any or all of its outputs may be fed to separate, more powerful amps if desired; when used in this way, the unit can be thought of as a surround sound processor/preamplifier.

The Dolby Pro-Logic circuitry used in the F-114 consists of a purely analog decoder with low-noise digital delay for the rear channels. Each of the three amplifier channels has an FTC power rating of 50 watts per channel into 8 ohms. Each can deliver 140 watts into 2 ohms under dynamic music conditions. The amplifier design uses discrete driver and output devices in a Darlington full-complementary configuration. A black-anodized, finned heat-sink provides the needed heat dissipation. A heavy double-shielded transformer, fast-recovery rectifier diodes, and large filter capacitors are used in the power supply. The amplifiers incorporate Luxman's Duo-Beta feedback design, utilizing one full-range feedback loop to widen bandwidth and improve transient response, and another, direct-coupled servo loop to maintain d.c. balance while providing good control of subsonic woofer motion.

The F-114 is supplied with a full-function remote control that, among other things, can be used to govern the unit's motor-driven master volume control. When the F-114 is hooked to a TV monitor, an on-screen display shows surround settings, rear delay time, and channel levels. A pink-noise test generator is provided for adjusting relative levels of all speakers when using Dolby Pro-Logic. Separate center- and rear-channel level-adjustment controls are found on both the front panel and the remote. Jacks are provided for control interlinks with some other Luxman components having "Bus Line" jacks, and for connection of remote-control receptors in other rooms.

Control Layout

Versatile as the F-114 is, Luxman has still managed to give it a fairly simple and unintimidating front-panel layout. The power switch is at the extreme left. Nearby is a display with an LED showing approximate input level for each channel and a digital readout showing time delay in mS or output level in dB. Further to the right are indicators for the surround mode in use. Mode selection is handled by a row of seven pushbuttons to the right of the display. The first three, for Dolby Pro-Logic, are "Normal," "Phantom" (for use without a center speaker), and "Wide" (for use when the center-channel speaker is a full-range unit able to handle bass frequencies). The next three buttons select "Simulated Stereo," "Hall," or "Stadium." The seventh pushbutton, "Bypass," changes the sound back to normal stereo, with only the stereo system's original left and right front amps and speakers operating. This mode might be used for comparison with surround stereo or for reproducing program sources that don't lend themselves to surround processing. A button for selecting the desired time delay is near the display, while a large rotary master volume control is at the right. Additional controls arranged along the lower edge of the front panel include center and rear speaker on/off buttons, rotary knobs for input level and balance, and buttons to raise and lower rear and center volume.

Most of the aforementioned functions are accessible from the remote control. Additional functions found only on the remote include "On/Off" and "Manual" buttons for the test-tone generator and a "Display" button used to show the unit's functional status on the screen of a connected video monitor.

The rear panel is equipped with a pair of line input jacks, fixed and variable preamplifier outputs for the front channels, fixed-level outputs for the rear and center channels (including a pair of center outputs, for some reason), and variable rear and center outputs connected by wire jumpers to their respective amplifier inputs. Five-way binding posts are provided for rear and center speaker connections. One video input and one video output are provided; presumably, those owning several video program sources will hook them to their main A/V receiver and connect the receiver's video output to the F-114, as shown by a diagram in the manual. Other jacks include a ground terminal, the "Serial Remote" input and output jacks for Luxman's multi-room remote-control system, and "Bus Line" jacks for hookups to other, similarly equipped Luxman components.

Use and Listening Tests

Setting up the Luxman F-114 and integrating it into my existing surround sound system involved substituting the unit for another preamplifier/surround sound processor I had installed more than a year ago. Amplifier components remained the same for my front-channel speakers, KEF 105 Series II units. I used a pair of fairly small Clements Audio Little "d" speakers for the rear channels and a self-powered Bose Video RoomMate for the center channel, connecting the latter to the center-channel preamp output of the Luxman F-114. Instead of listening to CDs, I chose to use the system for its primary purpose-viewing Dolby Surround-encoded motion pictures and listening to how well soundtracks would be decoded by this unit.

A recent videodisc I acquired is the French film Le Maitre de Musique (roughly translated, The Music Master), released on a Pioneer LaserDisc in Japan (PILF-1016). As all dialog is in French, with subtitles in Japanese, I had chosen this disc not for its story but because its soundtrack-the background music as well as selections that figure in the plot-includes 26 separate classical music excerpts and opera arias. Here in this superbly photographed period piece is everything from Mozart to Mahler, with bits of Verdi, Schumann, Bellini, and even Offenbach thrown in for good measure.

Dialog, using the ''Normal'' Dolby Pro-Logic mode, remained perfectly fixed on screen, where it belonged, while all of this musical treasure enveloped me just as I had hoped a soundtrack would in a Dolby Surround film. To my mind, this kind of visual and aural enjoyment is what home theater should be all about.

I played some concert videodiscs in both the "Hall" and "Stadium" modes and satisfied myself that the time-delay range is more than adequate for most types of music. With 80 mS of delay and using the "Hall" mode, I was able to approximate the acoustics of a small cathedral, let alone a large concert hall. My own preference was for a delay of about 30 to 40 mS while listening to orchestral works, as they might be heard in a typical concert hall. Particularly well reproduced in the "Hall" setting was an early LaserDisc, made in 1982 and issued by Pioneer Artists, featuring the famed Russian cellist/conductor Mstislav Rostropovich playing the Dvorak Cello Concerto in B Minor with the London Philharmonic Orchestra under the direction of Carlo Maria Giulini. This stereo recording was not Dolby encoded, but thanks to the recording's intelligent mix, the solo cello remained centered while the orchestral accompaniment spread out across my re-created soundstage. Rear channels contributed just the right amount of hall ambience, once I adjusted the parameters using the remote control. I find that a remote is especially useful when enjoying surround sound: It lets you make adjustments from your listening location instead of running up to the controls again and again and then discovering, after you finally return to your seat, that the settings aren't what you wanted after all.

The Luxman F-114 seems ideal for the owner of a stereo system who wants to add surround sound without having to scrap a current amplifying setup or receiver. Indeed, the F-114 offers easy (and relatively inexpensive) entry into the world of home theater.

Luxman F-114 Surround Processor/Amplifier photo