Kenwood KR-V127R Stereo Receiver Review

The Kenwood KR-V127R is a relatively compact, powerful stereo receiver with video switching capability and built-in amplifiers for driving surround-sound speakers. It includes audio matrixing and time-delay circuits for decoding Dolby Surround soundtracks or enhancing ordinary stereo programs.

The feature-laden KR-V127R also has a seven-band graphic equalizer in lieu of conventional tone controls, and its display serves as a real-time spectrum analyzer during normal operation. Five equalization curves of the user’s choice can be entered into memory in addition to five factory-set curves. The equalizer can be used either to modify a program signal before it is recorded or to modify the playback from any signal source.

The digital-synthesis am/fm tuner can be manually stepped in single-channel increments or scan continuously. Up to twenty station frequencies can be stored, in two banks of ten, for instant recall. The same ten pushbuttons can also be used to key in any frequency directly.

The input source is selected by a row of buttons along the bottom of the front panel. The selection is identified in large characters in the fluorescent display window. In tuner mode, the frequency and preset channel number are also shown, and up to four call letters can be memorized for display with each preset frequency.

When one of the volume buttons is pressed, the relative gain of the amplifier section (in 2-dB steps from 0 to —76 dB) temporarily replaces the call letters or source identification in the display. The level is also displayed as a series of lighted vertical bars of different lengths. Other indications in the display window show the operating status of the various front-panel controls, including balance and 20-dB muting.

The audio inputs of the Kenwood KR-V127R include phono (mm or MC), CD, tape 1, and tape 2 (monitor). It can also control the recording and playback functions of two VCR’s, including dubbing in either direction, and playback from a third video source (a VCR or videodisc player). The surround-sound function is controlled by two buttons, which turn it on and off and select one of its three operating modes: Dolby, Theater, and Stadium. The volume of the surround channels can be varied in 2-dB steps over a range of ± 20 dB.

The KR-V127R’s audio section is rated for 130 watts per channel, in normal stereo two-channel operation, into 8 ohms from 20 to 20,000 Hz with no more than 0.008 percent total harmonic distortion. In four-channel (surround) operation, the front channels are rated for 140 watts per channel into 8 ohms at 1,000 Hz with no more than 0.008 percent distortion, and the surround (rear) outputs are rated for 10 watts per channel into 8 ohms from 70 to 20,000 Hz with no more than 0.9 percent distortion.

The rear apron of the KR-V127R contains the audio and video input and output jacks, an output for a video monitor, inputs for a 75-ohm fm antenna and for an am wire antenna or the furnished loop, and coaxial input and output jacks for a cable tv source, which can be selected by a front-panel button, replacing the regular FM antenna. A System Control jack is used to connect the receiver with compatible Kenwood turntables, cassette decks, and CD players so that the input buttons on the receiver also switch the power to the other components. A rear-apron switch sets the amplifier’s operating voltage according to the speaker impedance: for 8 ohms and higher or for lower than 8 ohms. There are spring-loaded output connectors for two pairs of front speakers (they are connected in series when both are selected) and the rear speakers. The receiver is equipped with three switched AC outlets.

A wireless remote control duplicates almost all of the KR-V127R’s front-panel functions as well as many controls specific to the tv, CD, and tape sources that might be used in the system. The remote also switches the AC power for the stereo system and an associated tv set, and it has thirty unmarked keys that can be programmed to duplicate the controls of other remote units.

For all its complexity and power, the Kenwood KR-V 127R is surprisingly compact, measuring 16-1/2 inches wide, 14-1/2 inches deep, and 5-1/4 inches high. It weighs about 25-1/2 pounds. Price: $699.

Lab Tests

Although the top of the receiver became quite hot during its 1-hour preconditioning period, it was no more than mildly warm during normal operation. Into 8-ohm loads, the front outputs clipped at 162 watts per channel. The 4- and 2-ohm clipping outputs (with the rear-apron switch set to 4 ohms) were 150 and 206 watts, respectively. The surround-channel outputs clipped at 15 watts into 8-ohm loads. The slew factor exceeded 25, and the amplifier was stable with reactive simulated speaker loads.

With the receiver driving 8-ohm loads at maximum rated power, the distortion of the front channels was just under 0.01 percent from 20 to 1.000 Hz, increasing smoothly to 0.07 percent at 20,000 Hz. At half power and one-tenth power the characteristic was similar, with generally lower distortion readings. At 1.000 Hz into 8 ohms, the distortion decreased from 0.02 percent at 1 watt to 0.0055 percent at 50 watts before rising to 0.009 percent at 150 watts. Into loads of 4 and 2 ohms the curves were similar, with somewhat higher readings.

The built-in graphic equalizer performed as expected, although each of its individual controls affected the response over a three-octave range. Nevertheless, with a moderate amount of patience and practice it should be possible to obtain almost any response modification that would be required from a tone control. In the Dolby mode, the frequency response of the surround outputs conformed to the general requirements of Dolby Surround, dropping to — 3 dB at 30 and 7,500 Hz. The Theater mode yielded similar results, with slightly less low-frequency rolloff. Response in the Stadium mode was at its maximum between 50 and 500 Hz, falling off at higher frequencies to — 10 dB at 5,000 Hz.

The RIAA equalization error was less than 0.1 dB from 20 to 2,000 Hz, reaching a maximum of +0.3 dB at 8.000 Hz and returning to zero at 20.000 Hz. The phono input (MM) termination was 49,000 ohms in parallel with 183 picofarads. The phono input overloaded at levels from 84 to 92 millivolts (mv) between 20 and 20,000 Hz. The high-level input sensitivity, for a reference output of 1 watt, was 20.7 mv, and the phono sensitivities were 0.29 mv (mm) and 0.028 mv (mc). The respective A-weighted input noise levels, referred to a 1-watt output, were —76.5, —79.2, and -70 dB.

The fm tuner section was quite sensitive, with a usable sensitivity of 11 dBf in mono and 50-dB quieting sensitivities of 14 and 37 dBf in mono and stereo, respectively. Except for image rejection, which was rated as 43 dB and measured 39 dB, all of the fm measurements we made matched or surpassed the manufacturer’s ratings. The am tuner section’s frequency response was + 1.2, — 6 dB from 25 to 2,500 Hz.

Comments

Like most products, the Kenwood KR-V127R has a number of strong points mixed with a few weaknesses. Unlike most others we have tested, however, in the KR-V127R the gap between the two extremes is considerable.

First, the good news! The KR-V127R was a topnotch performer, one of the very few receivers in our experience to meet or surpass virtually all of its tuner specifications. In contrast with the many FM tuners whose antenna inputs are a poor match for our signal generator’s output impedance, which leads to “hot” coaxial cables and poor repeatability of measurements, the KR-V127R was totally unfussy and gave the same excellent readings no matter how the cables were dressed.

The amplifier section was also very good, with a remarkable power capability for its size and weight. Even if its noise and distortion did not approach unmeasurable levels, they were well below audibility. And, like the tuner, the amplifier had a rock-steady output and never showed any instability, regardless of the input and output signal grounds. Its protection relay acted when we tried to drive it to clipping into 2 ohms (which is specifically not recommended), and after a period of high-power testing the thermal-protection circuit shut the whole receiver off for about half an hour while it cooled down. But nothing blew—not even a fuse—or suffered any other damage.

We could only judge the surround-sound operation of the receiver subjectively. We felt that the circuits did enhance the overall sound to a worthwhile degree, though not as much as we have experienced from Dolby Pro Logic decoders or digital ambience synthesizers. In general, the Theater mode sounded best to us; the Stadium mode sounded worst because of its lack of high frequencies in the rear speakers.

Now for the “not so good” news. The receiver’s relatively small front panel contains some seventy (!) pushbuttons, which are mostly quite small, close to their neighbors, and nearly the same color as the panel. All are identified by markings, some in white but many in a light gray against a darker gray background. The crowded panel necessitates small lettering for these markings, and, frankly, it was a challenge even to find certain controls! A strong light and eye-level placement are needed for this receiver to be fully usable.

The supplied remote control could—and should—have been an ideal solution to the ergonomic problem, since it can be viewed under more ideal conditions. Unfortunately, the unit, about twice the size of most wireless remotes, contains no fewer than ninety-three buttons! And, what is worse, all ninety-three are identical in size and shape, and most of them are the same color as well. Doing something as basic as turning the radio on or off, or adjusting the volume, took real study of the controls to achieve.

What it comes down to is that the Kenwood KR-V127R is a first-class receiver, with more features, power, and just plain good performance than most of us will ever need, at a very reasonable price. But it also has the most complex control system I have encountered in a stereo component. I never did figure out how to use several of its features, and the manual’s instructions sometimes seemed to have little relation to what happened on the receiver itself. If you enjoy puzzles, however, the KR-V127R might be a challenge worth accepting.

Read all

Kenwood reviews

Read all