Pioneer VSX-D1S A/V receiver Review

The VSX-D1S is Pioneer’s most powerful audio/video receiver. It contains a versatile AM/FM tuner and a preamplifier with Dolby Pro Logic decoding as well as digital signal-processing (dsp) circuits that can synthesize four additional surround modes. All surround parameters (including the relative levels at all speakers, delay times, etc.) can be altered by the user and the results stored in memory as an additional option. The VSX-D1S has five power amplifiers: one each for left, right, and center front speakers and left and right rear speakers. The receiver’s operating features are so numerous that we can merely mention some of the most important ones.

The main (front) speaker amplifiers are rated to deliver 130 watts each into 8 ohms from 20 to 20,000 Hz with no more than 0.005 percent total harmonic distortion (THD). The center-channel and rear speaker amplifiers are rated at 40 watts each into 8 ohms at 1,000 Hz with 0.08 percent distortion. The preamplifier output and power-amplifier input for each channel are brought out to separate jacks on the rear apron, where removable jumper links permit the use of external power amplifiers.

The tuner section has preset memories for up to thirty stations, either am or fm, using only ten buttons. The display can be programmed to show the call letters and program category (jazz, rock, etc.) as well as the frequency of any preset station.

The preamplifier has audio inputs for a moving-magnet (MM) phono cartridge (with an input-sensitivity control), a CD player, two audio tape decks, another line source, a videodisc player (vdp), three vcr’s, and an additional video sound source. In addition to the composite (RCA-jack) inputs and outputs for three vcr’s, there are separate DIN sockets for use with S-video-compatible vcr’s. There is also an S-video input for a compatible videodisc player.

Video programs (excluding S-video) entering the receiver can be passed through an enhancer circuit to adjust picture quality. A novel split-screen feature enables the monitor to show the original picture on half the screen and the enhanced picture on the other half, simplifying adjustment. Up to five different settings can be stored.

Another novel feature of the VSX-D1S is its multiroom mode. The receiver can supply independent programs to two rooms, and with an accessory MR-100 remote sensor, users in the remote location can control its program source and volume level. When the VSX-D1S is used in this mode, its rear-channel amplifiers drive the remote speakers.

Below the large display window, numbered buttons select preset stations or give direct access to any frequency. Small round buttons to their right select the various factory-set surround modes, identified as Jazz, Dance, Church, Hall, and Theater. The Theater mode can be used with standard Dolby Pro Logic surround settings or with Dolby three-channel logic without a center speaker.

Twelve large, square buttons across the bottom of the panel select the audio and video input sources. Two smaller buttons to their left permit separate selection of program sources for listening and recording.

To the right of the display window is a large volume knob with a red LED index marker. Below it is the multipurpose jog knob, which controls several digitally operated functions, including am beat reduction (am b.r.), tuning, entering station call letters into memory (character), the video enhancer, delay for surround-sound modes, and echo density of the rear channels in a music surround mode (EFFECT).

A small JOG mode button near the dial toggles the control between its various functions, depending on the current operating mode (nonapplicable functions are locked out). In each case, turning the knob varies the setting for the selected function, with the current setting displayed in the window. In the tuning mode, it becomes a tuning knob, supplementing the buttons for step-by-step tuning, auto-scan tuning, preset selection, and direct frequency setting.

Other small buttons near the volume knob operate the audio muting, restore the default settings of the principal operating controls (return), turn on the Digital Simulated Stereo System (DSSS) for use with mono program material, and open the door that hides less-often-used controls. Pressing the door open button causes the entire lower portion of the panel, the part containing the input-selector buttons, to hinge downward, revealing a number of small buttons and the input jacks for VCR3.

Some of the hidden controls are used for tuner operation, such as step and scan tuning, storing station call letters in memory, preset storage, am b.r., and another tuning feature called Hyper Intelligent Tuning System (HITS), the main effect of which is to find the next receivable station in the band. Other controls modify the bass and treble response separately for front, rear, and center channels; there is also a midrange tone adjustment for the three front channels. Another group adjusts the relative levels in the center and rear channels and the overall left/right balance. A test-tone button activates a random-noise test signal that automatically steps through the five channels to help in balancing their levels for surround operation.

The display window, which measures 2-1/8 by 9-1/2 inches, contains a vast amount of information on the status of virtually every part of the receiver. A multibar display shows the program level separately for the left and right channels (front and rear) and the center channel. When you adjust the tone controls, this display changes to show the control settings; it reverts to level readings a few seconds after the adjustment is completed.

At the left of the panel are the power button, a direct button that bypasses all the signal-processing circuitry, and a button to activate the multiroom mode. There are also separate switches for connecting the two pairs of front speaker outputs and a stereo headphone jack.

The VSX-D1S is supplied with a wireless remote control that is designed to serve as a system control. About half of its buttons are duplicates of the receiver’s most commonly used controls (the master volume knob is motor-driven when the remote is used). The markings on the rest of the buttons indicate that they are intended to operate a cassette deck, a vcr, a CD player, a videodisc player, and a tv set. In the control’s SR Recall mode, these buttons are preprogrammed to operate Pioneer components identified with the SR logo.

The remote control is a “smart” one, however, and it can learn the infrared commands for most components from other manufacturers. Although Pioneer cannot guarantee that the remote unit will operate all the functions of every product, the manual offers suggestions for the most effective programming of the controller.

The rear apron, in addition to all the signal input and output jacks, has binding-post terminals for two pairs of front speakers and two center speakers (when it is not practical to locate a single speaker under or in front of the tv set, it may be possible to place speakers symmetrically on either side of it to serve the same purpose). The speaker terminals accept only stripped wire ends, not banana plugs). There are spring-loaded connectors for two rear speakers.

A power impedance selector on the rear apron reduces the operating voltage on the front-channel output transistors for safe operation with 4-ohm speakers. There are binding posts for a 300-ohm fm antenna and the supplied am loop antenna as well as a coaxial jack for a 75-ohm fm antenna. Two of the three AC outlets are switched.

The VSX-D1S is a large, heavy receiver, measuring 16-1/2 inches wide, 18 inches deep, and 6-3/8 inches high. It weighs 33 pounds. Price: $1,400.

Lab Tests

When we tested the VSX-D1S’s amplifiers, we did not attempt to drive all five simultaneously, which would be an unrealistic condition given their phase and amplitude relationships in the surround-sound modes. Instead, we drove the two front channels as for any stereo amplifier, and we later drove the center and rear amplifiers from their rear-panel inputs, bypassing the preamplifier section.

The receiver’s well-ventilated top cover became fairly hot during its preconditioning period and subsequent tests. With both front main channels driving 8-ohm loads at 1,000 Hz, the outputs clipped at 157 watts per channel. With 4-ohm loads the output at clipping increased to 210 watts per channel. The respective dynamic power outputs were 189 and 253 watts. We also measured dynamic power into 2 ohms, for a reading of 324 watts. We did not attempt 2-ohm operation in the continuous-power tests in view of the VSX-D1S’s very high power rating and the risk of blowing fuses or even damaging the receiver.

The rear and center channels each delivered 60 watts into 8 ohms. The 4-ohm output was 83 watts for the rear channels and 93 watts for the center channel. The fact that two channels were being driven in one case and one channel in the other probably explains the difference in available power. The dynamic power outputs of these amplifiers were essentially the same as their clipping-level outputs.

The 1,000-hz distortion (THD plus noise) of the front-channel amplifiers at 130 watts into 8 ohms was 0.02 to 0.04 percent from 20 to 4,000 Hz, rising to 0.06 percent at 20,000 Hz. At 1,000 Hz, it was 0.02 percent at 130 watts. Into 4 ohms, the distortion was about 0.015 percent just below the 210-watt clipping point. The distortion of the rear and center channels was 0.02 percent or less at 40 watts up to 2,000 Hz, increasing to 0.3 percent at 20,000 Hz.

The amplifier section’s frequency response (front channels), relative to the 1,000-hz level, was down 0.4 dB at 20 Hz and 1.5 dB at 20,000 Hz. In the Direct mode (bypassing the signal-processing circuits), the response was flat within ± 0.1 dB over the full range of 20 to 20,000 Hz.

The tone-control response curves were conventional, with the midrange control’s effect centered at 1,000 Hz. RIAA phono-equalization error was less than 0.5 dB from 20 to 20,000 Hz. The rear-channel amplifier response was down 0.1 dB at 20 and 10,000 Hz and 0.4 dB at 20,000 Hz. The switch-able loudness compensation boosted both low and high frequencies slightly, and its response was independent of the volume setting.

The amplifier section required an input of 15.3 millivolts (mV) at a high-level input or 0.28 mV at the phono input for a reference output of 1 watt into 8 ohms. The respective A-weighted noise levels were -76.2 and -70 dB. The high-level (CD) input overloaded at 2.3 volts, and the phono input overloaded at 128 mV at 1,000 Hz and 41.5 mV at 20 Hz. Phono response cut off very sharply above 20,000 Hz, preventing overload measurements at that frequency.

The FM tuner section had good 50-dB quieting sensitivity: 15 dBf in mono and 37.5 dBf in stereo. Mono usable sensitivity was 14.5 dBf, and the stereo threshold was 20 dBf. The fm tuner’s distortion at 65 dBf was 0.06 percent in mono and 0.155 percent in stereo, and the respective noise levels were —75.8 and -72 dB.

The fm frequency response was within +1, —0.3 dB from 30 to 15,000 Hz. Channel separation was 48 to 50 dB from 400 to 10,000 Hz, 38 dB at 20 Hz, and 44 dB at 15,000 Hz. Capture ratio was 2.3 dB, am rejection was 50 dB, and image rejection was 45 dB.

Selectivity was good, measuring 70 dB for alternate-channel (400-kHz) spacing and 10 dB for adjacent-channel (200-kHz) spacing. The 19-kHz pilot- carrier leakage was at a -56-dB level, and the 38-kHz component was undetectable. Power-line hum was -65 dB, predominantly at 120 Hz.

The am tuner’s frequency response was +1, -6 dB from 78 to 2,100 Hz. We also attempted to measure (and hear) the effect of the am beat-reduction circuit. Our measurements indicated that it produced a sharp dip in the audio output, tunable (with the jog knob) from as low as 1,000 Hz to higher than 10,000 Hz. The am frequency response cut off quite sharply above 3,000 Hz, however, and measurement of the null depth was difficult. It appeared to be at least 10 dB.

Comments

The Pioneer VSX-D1S is an unusual, unconventional receiver in respect to its overall concept, features, and performance. At first acquaintance, it is nothing less than overwhelming despite the relatively uncluttered, open appearance of the front panel. The rear apron is enough to drive anyone to the manual.

The manual, all fifty pages of it, is complete and for the most part well written. Nevertheless, there is a lot of it to study, and no matter how familiar you may be with modern stereo A/V receivers, I guarantee that you will not get too far with this one until you get some hands-on experience with it, manual at the ready.

We did not use the receiver with video or phono sources, nor did we attempt multiroom operation (the optional remote sensor was not included). We did use it in a four-speaker surround-sound installation, mostly with tuner and CD programs, and with a videodisc player and laserdiscs to judge its Dolby Pro Logic performance.

Briefly, the VSX-D1S is a component that grows on you with use. At first, I was somewhat turned off by the complexity of its many control functions and features, often identified with obscure nomenclature or acronyms, as well as by a couple of below-average test results (for instance, the CD and other high-level inputs could be overloaded by some typical input signal levels). But after extended use, its performance and versatility prevailed.

The fm tuner section performed well with respect to distortion, interference rejection, and sensitivity. Not only does the VSX-D1S have many more preset memories than most other receivers, but the option of manual tuning with the jog control gives it the feel and convenience of analog tuning along with the accuracy and stability of digital frequency synthesis.

The Digital Simulated Stereo System feature is supposed to synthesize a stereo-like effect from mono programs. I tried it with a variety of programs but was unable to obtain anything audibly different from the source.

The am tuner was typical, which is to say about as far from high fidelity as one can get. The justification for the AM beat reducer seems debatable, since I cannot imagine how a beat tone between stations (10 kHz apart in North America) could possibly be audible through a bandwidth of less than 3,000 Hz. I was never able to hear such a tone, so I cannot judge how effective the tunable notch would have been in eliminating it.

Fortunately, the benefits of the receiver’s other features were very audible and more than made up for its few less-impressive qualities. Obviously, the VSX-D1S is a true powerhouse receiver, more than able to drive the vast majority of speaker systems to their limits without straining its amplifiers. If you want to optimize its performance for Dolby Pro Logic playback, you can flip a switch on the rear apron to drop the left and right front amplifiers' ratings to 70 watts each and increase the rear amplifiers to 50 watts per channel and the center amplifier to 70 watts. This will give better power distribution for Dolby Surround soundtracks, which put a lot of energy into the center channel.

The music surround effects were excellent. The factory-preset characteristics should be suitable for almost any needs, but they can be modified as required and saved as optional modes. Adjusting the “effect level” with the jog control can make a huge difference in the sound quality. Although the manual is not at all specific as to the parameter(s) the control adjusts, it seemed to be largely the echo density (and possibly level).

The final proof of this system’s merits was its Dolby Pro Logic surround mode, which was excellent. Although we did not use the receiver to control the video signals from the laserdisc player, the sound from the laserdiscs we played was everything we would expect to hear from a Dolby Pro Logic setup.

All in all, the Pioneer VSX-D1S is a large, heavy, powerful, expensive, highly versatile, and fine-sounding receiver. Although it might not be suitable for a neophyte, and could challenge the most experienced audiophile, the effort of mastering its intricacies is well justified by the results.

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