Vector's Incredible Music Machine
Vector Research VRX-9500 AM FM receiver, with DBX tape disc noise reduction.
Dimensions: 17 1/4 by 5 1/4 Inches (front panel). 13 3/4 Inches deep plus clearance for controls and connections. AC convenience outlets: two switched (200 watts max. total), one unswitched (200 watts max.).
Price: $1.000: optional VRC-11 remote-control unit. S85. Warranty: "limited," two years Darts and labor. Manufacturer: made in Japan for Vector Research, Inc., 20600 Nordhotf St., Chatsworth. Calif. 91311.
FM tuner section:
MONO FREQUENCY RESPONSE
----------Much of the VRX-9500's flexibility is summed up in this
section of the front panel. The buttons below the preset-indicator
lamps serve to set and select station presets and also as a programming
keyboard in conjunction with the clock/timer program-mode switch
below. The two rotary tape switches and DBX control buttons enable
you to record, play back, and copy standard and DBX discs and tapes
in almost every possible way.
THE SHEER QUANTITY OF FEATURES embodied in the VRX-9500 receiver is startling, and that so pace-setting a receiver should have come from a company that has been on the scene only a few years is at first glance even more startling. Yet this is probably just the sort of product we should have expected from Vector Research. It represents the sort of fresh design thinking and synthesis of current technology that the company has said it intends to make its hall marks and evinces the awareness of the special needs of recordists that is so much in evidence in the company's cassette decks.
First, let's examine the VRX-9500's front panel. There is no ON switch as such; instead, when you press the selector button for any function the receiver turns on.
When you press OFF, the tuner's frequency readout becomes a twenty-four-hour clock (reading " 17:00" for 9:00 p.m., for instance), which works in conjunction with the three-way built-in timer. The timer has three separate functions: It can turn the receiver on and off each day at the times for which you program it; it can be programmed for a one-time turn-on/turn-off cycle in addition to the daily cycle; and it has a sleep feature that automatically turns the unit off after a preset period of time has elapsed. (Both the daily and the one-time cycle include input-selector programming, as well.) The interrelationships among these three timer modes are quite complex in terms of what overrides what, but they are very well thought out and painstakingly explained in the manual. Incidentally, you can always check the time (clock) or timer programming (TIMER READ) with the tuner section turned on, even though its frequency readout normally pre-empts the clock display.
There is also provision for timer-controlled synchronization with Vector's VCX-800 cassette deck, by means of a special jack on the back of the VRX-9500, and a jack for the cable from the optional VRC 11 remote control. (Because we had neither of the ancillary units, we didn't test these features.) A compartment in the rear panel holds a Z battery (composed of four AA cells) to energize the memory functions during power outages or periods when the receiver is not connected to a wall socket.
And there are back-panel pre-out/main-in amp jumpers whose jacks can be used to patch in equalizers, time-delay units, and so forth.
Possibly the most complex feature of the receiver (we found it the most difficult to master, but that's partly a question of how much we had to unlearn from our experience with more conventional switching) is its DBX/dubbing section. The DBX functions are controlled by four pushbuttons three of which, ENCODE, DECODE, and BYPASS, are interdependent and inter locked, while the fourth, RECORD/COPY, operates independently. Because there is only one set of DBX circuits, you can't select ENCODE and DECODE simultaneously and thus can't monitor a DBX recording off the tape, even if you have a monitor-head recorder. Presumably to prevent you from monitoring an undecoded signal, the DBX RECORD/COPY automatically disables the monitoring function and either returns you to the source signal or mutes the output, depending on how other switching is set.
This scheme may sound unnecessarily complicated, but it's really not, considering all the things it makes possible: decoded playback of DBX discs or tapes, undecoded tape copies of DBX tapes or discs, decoded (or differently encoded) copies of DBX tapes or discs, non-DBX copies of non DBX discs or tapes, and DBX copies of non-DBX discs or tapes. Any scheme we can conceive for simplifying the switching would materially reduce these options.
With the DBX section bypassed, the dubbing and monitoring switches operate in the normal, full-function manner, enabling you to monitor either deck while you're dubbing (for example) and to dub in either direction between the two decks.
The tone controls also require a little thought and practice for full mastery. The three-band (bass, midrange, treble), defeatable system offers two adjustments in each band: for amplitude and frequency. Data from Diversified Science Laboratories show that at the detented center of the frequency adjustment the TREBLE shelves at about ± 12 dB above 20 kHz or so-with the whole response curve capable of being displaced about one octave upward or one and a half octaves downward. The MIDRANGE offers ± 10 dB maximum, with a similar frequency adjustment range above and below its detented position (which is centered just above I kHz). The BASS shelves below about 80 Hz at the detent, with a slightly wider amplitude range than the MIDRANGE, and allows a frequency shift upward by a little more than an octave and downward by something less than an octave.
This range of options approaches the flexibility and equals the smoothness of parametric equalization if you're willing to rely on your ears in fine-tuning it. Admittedly, it can't manage the narrow-band (high-Q) effects of a parametric, and at minimal boost or cut settings the controls' effects are usually very subtle. On the other hand, it can more nearly approximate ideal response curves over a much wider range of conditions than one could even hope for with conventional tone controls, and with out the ripple that tends to afflict the response of graphic equalizers where hefty boost or cut is called for over several adjacent bands.
The AM/FM tuner, which has eight station presets for each band, sweeps up or down the chosen band continuously as long as you depress the tuning button in the manual mode. It advances in discrete hops (of 0.1 MHz on FM or 10 kHz on AM) if you just tap the tuning button in manual or continuously until it arrives at a "receivable" station in the automatic mode. If you live outside a strong signal area, you may find the 9500's definition of "receivability" somewhat persnickety: Even when it's switched to MONO, it will pass over stations that light the first signal-strength LED (at about 30 dBf-where mono quieting runs some 65 dB in the DSL data). It seems to need enough signal to trip the stereo thresh old (at 50 dB of stereo quieting-better than 70 dB in mono) before the scanning will stop. Thus, both the signal strength display and the scanning are somewhat less sensitive than average. So is the stereo switching (though without a BLEND feature, many listeners may be reluctant to go for stereo on stations too weak to achieve 50 dB of quieting).
The five-LED signal-strength display can be converted to register multipath at the flick of a switch, but this function also seems relatively insensitive. In a fringe area where other tuners so equipped frequently show considerable multipath, the 9500 registers none. In more typical locations, how ever, where both signal strength and multi-path are considerably higher, the tuner section should really come into its own.
Among the generally very good FM measurements, selectivity should be singled out for special mention. Not only is the usual alternate-channel figure better than usual, but DSL measured 8 dB of adjacent-channel selectivity, which is outstanding.
Even for a top receiver, the amplifier section is opulent, delivering more than 20 dBW (100 watts) per channel into 8 ohms on a continuous basis and the equivalent of 21 1/4 dBW (133 watts) on pulses that more nearly simulate music. Distortion is low and is dominated by the relatively benign second harmonic; intermodulation, which usually is about the same (and in that case goes unremarked in our reports) is here noticeably lower. The infrasonic filter is steep enough to be effective, and though its turnover frequency is, perhaps, a hair higher than average, it is low enough to be below the lower limit of virtually all speakers and musical material. The loudness compensation, which adds about 10 dB in the deep bass and 6 dB in the extreme treble, is unaffected by the VOLUME setting in DSL's tests and strikes us as somewhat redundant, given the unusually capable tone controls. Incidentally, the power meters at the upper left of the front panel are calibrated from 0.05 to 180 watts (-13 to +22 1/2 dBW) into 8 ohms, in steps of approximately 3 dB; a switch increases by 10 dB (ten-fold) the display's sensitivity.
Obviously, this is not a receiver whose capabilities can be assessed at a glance. Nor is it one for which an objective "bottom-line" value assessment is even conceivable, since its multitude of features must be measured, one by one and together, against the needs of individual users. You'll certainly find specifics that don't do much for you-perhaps the power metering or timer turn-on-but their presence doesn't diminish the receiver. Indeed, the diversity of its capabilities is remarkable-perhaps unprecedented. And when you consider what it would cost you to add them all to a conventional receiver of similar performance, by means of outboard accessory units, the VRX-9500 qualifies as a bargain. We suggest that you look at all the features that can be useful to you and make your assessment on that basis. We find it captivating.
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(High Fidelity, Jan. 1983)
Also see:
Technics SA-GX910 A/V Receiver (AUDIO mag, July 1992)
Technics SU-V9 Integrated amplifier (Equip. Report, Jan 1983)