Technics SA-TX1000 AV-receiver

Designing a Home THX receiver can't be easy. Not only do the engineers have to add to a normal receiver all the THX processing used to modify the outputs of a Dolby Pro Logic decoder, but they must also comply with demanding THX specifications for the power-amplifier sections. So it's perhaps no wonder that Technics, one of the first companies to issue THX-certified home theater equipment, is only the second to produce a Home THX receiver, the SA-TX1000.

The SA-TX1000 does indeed meet those requirements, with ratings of 120 watts per channel to the front speakers at 1 kHz into 6 ohms in surround mode and 130 watts per channel in regular stereo operation (a negligible 0.35-dB difference). The surround channels are driven by separate 55-watt amplifiers. This high power capability - 480 watts total - is obtained from what is a relatively small enclose sure, though the SA-TX1000 is still large and heavy for a receiver.

Technics says the receiver's compactness is made possible by the company's new Class H+ amplifier circuit, which is designed to enable high power outputs with less heat dissipation than is possible with conventional Class AB amplifiers. And to reduce heat-sinking requirements further, there is a low-noise fan in the back that comes on when the power output rises beyond a certain point.

For a top-of-the-line A/V receiver, the SA-TX1000 has a comparatively small feature set. In addition to the internal AM/FM tuner, there are only five external inputs, designated for a CD player, an audio tape deck, a laserdisc player, a videocassette recorder (VCR1), and a videocassette player (VCR2). The VCR2 inputs are accessible on the front panel as well as the back. Both composite- and S-video connections are provided for the laserdisc player and VCR1, but, as usual, there is no conversion between formats, only separate composite- and S-video monitor outputs. There is no phono input.

Rear-panel connections include amplifier outputs for one complete set of home theater speakers (left, center, right, and two surrounds), as well as a set of surround-decoder line-level outputs. All incorporate Home THX processing when it is switched in. There is also a subwoofer output with a built-in 24-dB-per-octave crossover fixed at the THX standard of 80 Hz. Turning this output on with its nearby switch also switches in 80-Hz, 12-dB-per-octave high-pass filters on the outputs to the other speakers, promoting cleaner sound by relieving them of the burden of trying to reproduce frequencies that are already being handled by the subwoofer. Other rear-panel facilities include two switched AC convenience outlets, outputs for a second set of left/right stereo speakers, and the AM and FM antenna connectors.

Surround modes number three: standard Dolby Pro Logic, THX, and Dolby 3 Stereo (a Pro Logic mode that folds the surround outputs into the front speakers if you don't have separate surround speakers). Switching to THX mode throws in all three processing functions required for Home THX certification: re-equalization (a mild high-frequency rolloff to compensate, for proper balance in the home, soundtracks originally equalized for theater playback), surround de-correlation (a continuous phase scrambling of the two surround outputs relative to each other, to increase diffusion and reduce localizability of the surround speakers), and surround timbre matching (to more closely match the sound coming from side-mounted surrounds with that from the fronts).

Besides the input-selector and surround-mode switches, other front-pan-el facilities include the large tuning and volume knobs, a Vi-inch headphone jack, the speaker selector switches, and small bass, treble, and balance knobs. The thirty-preset tuner section can be tuned in several different ways, controlled by mode buttons and a numerical keypad. Finally, a complete set of surround-setup controls are provided for surround delay (15 to 30 milliseconds in 5-millisecond steps), center mode, and the relative level of each speaker. The THX level-match test signal is activated by another button, and the subwoofer output is thoughtfully included in the signal sequence.

On the test bench, the SA-TX1000 proved to be a competent performer, capable of delivering large amounts of short-term power to low-impedance loads. Following the present fashion, the tone controls provide small changes in response for the first half of their rotation in either direction. The FM tuner section was average to good, the AM section (as usual) average to bad, with the dismal frequency response that is all too common to the breed.

Measured surround performance was generally fine. Particularly good was the perfect surround-channel level calibration in THX mode. Still, while the surround noise reduction had good frequency tracking, it overexpanded by about 2 dB at the lowest test level (-40 dB referred to a 141.4-millivolt input), meaning that the surround speakers will be about 2 dB too soft when the program material's surround content is low. This error is slightly larger than we have been seeing lately but is of little obvious audible consequence. More significant is the somewhat higher than average noise in the surround outputs, which can become audible in some situations if you're seated outside the null of a Home THX surround speaker.

For this price and power level, users might reasonably expect real multiway binding posts for speaker connectors. With the SA-TX1000, if you try to insert dual banana plugs-still the easiest-to-use high-current speaker connectors - you'll find that the "jacks" are not quite spaced correctly and that, in any event, the connectors are actually thumbscrew terminals that accept only stripped wires. In the absence of genuine banana-plug-compatible binding posts, it would be better to have connectors more conveniently fingerspaced for easy and reliable hookup than the ones supplied. And in this price range, I would prefer to see something better than the thumbscrews used as the FM antenna input, which on other, less-expensive receivers is sometimes a real F connector. Even the supplied AM antenna comes with its own plug-in connector.

There are a few other ergonomic problems with the rear panel, though none of them major. The audio and video connectors are arranged so that it is very confusing to change connections by feeling around from the front. Also, the surround- and center-channel decoder-output jacks are turned on only when at least one of the front-panel speaker switches is turned on. The reason is probably to reduce switching complexity within the receiver and to prevent user confusion when turning off all the speaker switches fails to turn off all the speakers in systems using external amplifiers for those channels. On the other hand, it makes it inconvenient to use the decoder outputs to drive a remote surround system.

There are plenty of things to admire about the SA-TX1000's operation, however. The tuning knob, for example, can be switched into auto-search or a flywheel-like manual mode. You can also tune by direct numerical input of the station frequency via the front-panel buttons (the numerical buttons on the remote select only among presets). Selection of which VCR2 input is active is via a front-panel button, which gives the receiver an additional A/V input, though one that is not always accessible from the remote. And whatever else I might not have liked about them, the speaker connectors are logically arrayed: The upper connectors all go to left-channel speakers.

The lettering showing the selected input in the front-panel display is easy to read from across the room. The display is also tied to the potentially useful panic button, which is located next to the volume control knob and labeled "Help." Press it, and the front panel will tell you whether a switch setting (a misset tape-monitor switch, for example) is responsible if, say, you are not hearing anything. Hold "Help" down for a few seconds, and all the receiver's factory settings are restored (except for any tuner presets).

And then there's the sound quality. The SA-TX1000 is a solid performer on both music recordings and soundtracks. In straight music reproduction, its generous power reserves enable distortion-free playback at very high levels. I was disappointed, however, that Technics did not see fit to include even the most basic of music-enhancement processing modes in a receiver of this rank. Simply turning the surround decoder off and feeding a delayed signal to the surround speakers could yield appreciable benefits with many types of music and would be far more useful than the Dolby 3 Stereo mode that is provided (not many people who buy a Home THX receiver will lack surround speakers).

Both Dolby Pro Logic surround decoding and the added Home THX processing were accurate and clean, our only quibble being the slightly elevated surround-channel noise. When connected to a set of THX-certified speakers (including a powered subwoofer) and thrown into THX mode, the SA-TX1000 delivers as much impact as you could expect from a soundtrack.

That is precisely what the Home THX specs are intended to deliver: dubbing-stage sound quality free from added reverberation or ambience. Dialogue clarity was always excellent, soundtrack harshness at high playback levels was reduced, and the surrounds always produced the desired sonic envelopment with less of the "swimmy" tonal quality I've heard from some other Home THX processors. And since the benefits provided by the Home THX speaker and processor standards are more or less independent of each other, you'll get much the same sound quality when using carefully selected non-THX speakers, provided the surrounds are dipoles placed to the sides.

Even something as simple as the THX volume-control calibration has tangible benefits. For example, with the SA-TX1000, if your speakers have impedance ratings of 6 ohms or greater and sensitivity ratings of 87 dB or higher, and if, when playing a CD or laserdisc, you can get the sound loud enough without turning the volume past 12 o'clock, then you can be sure that the receiver will never be running into clipping regardless of the music. (Some underrecorded discs may require higher volume settings.) Using the SA-TX1000, you may be surprised, and you'll definitely be pleased, to learn that a receiver rated at "only" 120 watts per channel can produce what are enormous sound levels in domestic listening. I just wish the marker on the volume control were more easily visible at a distance.

THX approval of a component assures only that certain aspects of its performance meet certain requirements. It's up to the manufacturer then to provide the electronics-to-user link to make a basically well-performing component easy to use - and to hook up. Overall, Technics has succeeded admirably, and at the lowest price yet for a complete set of Home THX electronics. The SA-TX1000 is a reasonably easy-to-install and exceptionally easy-to-use home theater receiver - of somewhat limited versatility, perhaps, but of excellent listening quality, especially on soundtracks.

Technics SA-TX1000 AV-receiver photo