Between the AES convention in Los Angeles and the SCES in Chicago, it seems like I have been reporting on new audio products ad infinitum. Herewith (and with a sigh of relief), I present a near-final roundup of interesting new audio equipment from the SCES.
As I have noted in reviews of the past several shows, the horsepower race in receivers has indisputably ended, probably none too soon, and I understand that sales of receivers of more than 100 watts per channel are considerably depressed. Probably this stems from a combination of price resistance to the high cost of big-wattage receivers and their sheer bulk. On the other hand, the cost of such refinements as quartz, PLL tuning; d.c. amplifiers with fast rise times and high slew rates; digital frequency readout, etc., puts many receivers into the high priced category. Frankly, I have never understood the rationale of the receiver market. To me, once an audiophile develops a certain degree of sophistication, I feel that he will reject receivers in favor of the flexibility and highly specialized qualities of separate components. I certainly have no quarrel with receiver engineers who incorporate refinements in their units to make them more salable. However, I find it a bit incongruous to find a $750 receiver with a built-in pre-preamp for moving-coil cartridges, which on aver age cost about one-third as much as the receiver! Be that as it may, there was a myriad of receivers at the SCES in all price ranges, all with bountiful features in this most fiercely competitive of all hi-fi products. A few that caught my eye were the new Kenwood Hi-Speed Model KR-8050, a 120-watt-per-channel unit, with their pulse-count detector FM tuner and amplifier with a slew rate of 200 volts per micro second; the Sansui Model G-7700, an other 120-watt-per-channel receiver, with d.c. amplification, digital quartz PLL, and Dolby noise reduction; the Yamaha Model CR2040, still another 120-watt-per-channel unit which features bass, treble, and midrange tone controls with continuously variable turnover frequencies, PLL and pre-preamp for moving-coil cartridges.
New Amps
I know some far-out audiophiles (in the guise of friends of dealers) who stalk the corridors of the hotels át the SCES which host the high-end, esoteric exhibitors, looking for the new and nifty in preamps and amplifiers. Al though I thought there were fewer high-technology amplifiers than usual, there were a number of interesting new designs .... David Hafler, who re-entered the kit market with his remarkably successful DH-101 preamplifier, has introduced his new DH-200 100-watt-per-channel amplifier. Available as a factory-built or kit unit (with the latter at less than $300), the DH-200 features exceptionally low THD and IM distortion and very low values of TIM. In fact, his sales brochure shows a series of spectrum analysis photos of IM content of his amplifier versus some decidedly unflattering views of competing amplifiers. The DH-200 can be bridged to a 300 watt/ channel monophonic amplifier. For those who need brute power, the new Audire DM-700 may well be the answer at a relatively modest $1,200.00.
The product of former space-program engineer Julius Siksnius, the DM-700 can deliver over 400 watts/channel be fore clipping, is said to be very stable for all types of speaker loads, and can put out as much as 700 watts/channel into two-ohm loads. It is a pretty fast unit at 80 V/uS, and I heard some of my own direct-disc recordings through, a pair of Dahlquists, and the sound was smooth on the top, finely detailed, with solid, clean bass.
Audionics of Oregon is a small company doing big things. To wit, after years of work and cooperation with Wesley Ruggles of Tate Systems, they have introduced their Space and Im age Composer unit. Essentially this combines super-sophisticated SQ de coder (with over 40 dB of interchannel separation) and the Tate stereo directional enhancement system which can retrieve out-of-phase ambient information and highly directional sound vectors from conventional stereo recordings. With separation and "panorama" controls to augment and facilitate this information retrieval, this unit is far beyond any similar device in the past. For one thing, it operates as a Class-A device with exceptionally low distortion. Among its unique features is "axial tilt" correction, which electronically corrects by plus or minus seven degrees deviation from true perpendicularity of the phono stylus in the record groove. There is also a tri angular display of LEDs which gives visual indication of the directionality of sounds. Quite apart from what feelings you might have about quadraphonics and SQ, this system does some really extraordinary things in the way of stereo enhancement and image synthesis. In due course, I'll bring you a full report on this device. Besides this unit, Audionics introduced their interesting BA-150 analog/digital hybrid solid-state/tube stereo amplifier. This is the final result of the David Berning (of the National Bureau of Standards) design of several years ago. In this unit a Class-A solid-state circuit drives pairs of 6FL6 tubes (normally a pentode used in the horizontal circuits of color TV receivers) to an output of 150 watts/channel into either 4, 8 or 16 ohms. As most users of tube amplifiers are aware, their ongoing problems are tube life and the maintenance of proper bias and balance throughout the tube life, as well as the necessity of obtaining matched tube pairs when replacement is necessary. In this BA-150, a CMOS digital logic circuit samples the operating parameters of the output tubes seven times per second and automatically and continuously adjusts tube bias and balance to the proper values.
With this system, matched tubes are not needed, and the life of the 6LF6 is estimated at over 30,000 hours! Another unique feature of the BA-150 is a front-panel switch which gives the user the option of applying 14-dB, 8-dB, or 0-dB negative feedback. I freely admit I am not a tube man, but many audiophiles are aficionados of tube amps, as witness the devotees of Audio Research. Incidentally, after having decided not to manufacture tube amplifiers anymore, Audio Research has evidently changed their mind and had a new 80 watt/channel tube amp at the SCES. In any case, my antipathies aside, this BA-150, while a hybrid sys- tem, has the best sound of any tube amplifier in my experience.
Crown can truly be credited with starting the "super power" amplifier business with its pioneering DC-300. After several updatings of this amplifier, now they have an entirely new design, the PSA-2, rated at 220 watts per channel into 8 ohms and, in its mono bridged mode, a whopping 700 watts into 8 ohms! The "SA" designation stands for self-analyzing, and, literally, Crown has an analog computer in each half of the output stages to monitor the operating parameters of the 16 output transistors used in this amplifier. Unlike its predecessor, the PSA-2 has a two-speed, forced-air cooling system and a power transformer for each channel, rather than the single common transformer used in the DC-300. Crown claims very low values of TIM for this amplifier and, with a slew rate of 30 V/uS, is considerably faster than the older amplifier.
Crown also introduced its new DL-2, "digilogic control center" and preamp, which has to be the ultimate "whistle and bells" system. A fascinating unit, with digital readouts of gain and computer interface buss, with separate phono module (and, in the last few days, their new moving-coil phono module), this is far too complex for description report will be forthcoming.
It is always a pleasure to visit Mark Levinson's room, where he displays and demonstrates the fruits of his on going devotion to his philosophy of "no compromise" audio technology. He has made some subtle refinements to his HQD loudspeaker/amplifier sys tem, resulting in higher output capabilities and even greater sonic purity.
Mark was playing some tape recordings on his ML-5 ... a Studer A80 modified with Levinson record and play back electronics. The recordings were made on this tape machine by Peter McGrath, the very bright and articulate owner of Sound Components, Inc., of Coral Gables, Fla., who is one of Mark's premier dealers in the U.S.
Peter used a "purist" technique of a pair of omnidirectional Bruel and Kjaer microphones, with a specially modified Levinson LNP-2 preamplifier as his recording "console." A Chopin piano concerto was particularly well recorded, and, as heard through the HQD system, the reproduction was stunning in its clarity, transparency, and sheer uncolored musicality. Once again, the best sound at the SCES. On display was Mark Levinson's newest item, the ML-3 stereo power amplifier. This 120 Ib. monster, sensibly equipped with handles front and rear so that two people can safely cope with its bulk, is built with the same "no holds barred" quality and precision of Mark's fabulous ML-2 Class-A amplifier. He uses a 1.2-kV/A toroidal transformer for each channel of the unit, along with 20 out put transistors per channel! This Class AB amplifier is rated nominally at 200 watts per channel, but more importantly, it is capable of 45 volt pulses and a rather staggering current output of 30 amperes per channel. More about this $3,000.00 beauty at a later date.
Speaker Intros
Now to loudspeakers ... needless to say, there were acres of them, a benumbing array of walnut boxes, generally of a stale sameness. As usual, I have to throw barbs at a great many speaker exhibitors for their simply awful demonstrations. Poor positioning, poor amplifier interfacing, incredibly bad demo music, terrible balances and gross distortions, all of which apparently were not audible to the generally inept personnel. Thank goodness, there are always notable exceptions to this cacophony, with some fine loudspeakers being demonstrated.
In my report on the AES convention, I mentioned Bob Fulton's new Premiere loudspeaker, an evolutionary de sign of his "J" system. This imposing monolith of a speaker stands 60 inches high, is 25 inches wide, and 22 inches deep. The speaker driver complement is one 12-in. subwoofer, one 12-in. mid-woofer, one 10-in. upper woofer, one 8-in. midrange, and three special tweeters. Bob has abandoned the electrostatic tweeter array he used in the "J" system, mainly because of power handling limitations. His proprietary three-tweeter array is fused to handle one kilowatt of input! Crossover frequencies are 39 Hz, 122 Hz, 425 Hz, 2.4 kHz, 8 kHz, and a somewhat optimistic 26 kHz! I'll buy a bottle of Dom Perignon champagne for anyone who can adjust the top tweeter by ear. Well, Bob has some interesting theories on the production of ultra low- and high-frequency difference tones in a sym phony orchestra, and he would rather offer the bandwidth for the probability of these frequencies than ignore them.
As you would expect, the crossover network is very complex indeed, and it can be used for bi-amping or bi-wiring inputs. The Premiere can handle power inputs of more than 400 watts, and it can produce some awesome sonorities. The system is phase compensated, and imaging is very precise and stable.
Throughout its entire range the Premiere is very smooth and neutral, with no obtrusive resonances. Strings are a special delight, free of the stridency that faults so many systems. Bass is subterranean, solid, with no overhang.
If you can afford $4,900.00 per pair, you get one of the most musical speakers extant and one of the few speakers capable of coping with the dynamics of digital recording. If the Premiere is too rich for your musical diet, Bob Fulton has an alternative in his new Nuance speaker system, a sort of baby brother of the Premiere.
Standing a more modest 34 inches high, the Nuance is 14 in. wide and 13 in. deep. The speaker complement is one 10-in. woofer, one 5-in. mid range, one mid-tweeter, and one super-tweeter. Crossover frequencies are 760 Hz, 6.5 kHz, and 15 kHz. Here too, the crossover permits bi-amping and bi wiring. The Nuance has many characteristics of the Premiere ... quite smooth sound, detailed and sweet top end, good imaging, and bass claimed to be a respectable 38 Hz. At $990.00 per pair, the Nuance should fare well in the marketplace. Bob Fulton doesn't have dealers in every hamlet, so if you want information on his products he can be reached at the new location of Fulton Musical Industries, 4204 Brunswick Ave. N., Minneapolis, Minn. 55422; tel: 612/537-7076.
Acoustat was on hand with their full-range electrostatic speakers, now featuring their impressive Monitor Four unit in a redesigned cabinet sans the pedestal of the earlier unit. Brings down the bulk a bit, and permits better coupling to the room. The Acoustat X original design has been replaced with the Monitor Three. This uses their new "thin-wing" array of electrostatic panels to eliminate panel-frame resonances. Output has been increased and is now claimed to be a maximum of 110 dB at 20 feet from a pair of the units in a 14x24-foot room. As usual with Acoustat, a lovely clean sound, with sparkling transients and well-chosen demo material.
JBL was showing its new L150 speaker, a sort of scaled-down consumer version of last year's big L220 system. The system features a newly developed 12-in. woofer, with a 3-in. hand-wound voice coil, and a 10 1/2-1b. ferrite magnet. A 12-in. passive radiator is also used in the bass section. A 5-in. midrange, with 3/8-in. voice coil is placed in its own sub-chamber, and high frequencies are handled by a 1-in. dome radiator. The speaker is in the JBL tradition of high output, with lots of punch and presence, and solid bass. An indication of this is their recommendation that best performance is with amplifiers of up to 300 watts per channel.
Last, but hardly least in loudspeakers at the SCES, was the latest offering of B&W ... Bowers & Wilkins of England. This was their Model 801, the first of what they call their Series 80 systems. Genial John Bowers was on hand to explain that the 801 is B&W's first "no compromise; cost no object" speaker system. All the resources of modern technology were brought to bear in the design of the 801. Thus, a laser interferometer, courtesy of the Atomic Energy Research Establishment at Harwell, was used to measure vibrational modes in the speaker drive units, and this was interfaced with the company's in-house computer. Cross over networks were designed by computer synthesis, and special materials developed for the cones of the drive units. A three-way system, the 801 em ploys a 270-mm woofer with a thermo plastic cone and PVA compound coating, the 100-mm midrange driver is made of Kevlar, an aromatic polyamide fiber matrix, PVA impregnated, and a 26-mm tweeter made of multi-filament polyester weave, with a voice coil treated with high-temperature epoxy. The low-frequency system is a closed-box acoustic suspension, with system resonance at 37 Hz. Mid- and high-frequency drivers are in their own enclosures, and the entire system is phase compensated. There is a great deal more to the 801, which we will report on at a later date. The B&W demonstration was, as always, a model of a civilized, professional presentation, completely unostentatious and using superb demonstration material.
The B&W 801 has to be one of the most important speaker designs in some time. It is meant to be used as a monitor in the strict sense of that abused term. It is capable of 106 dB SPL in rooms up to 7,000 cubic feet, and, with a special protection circuit, there's no upper limit placed on amplifier power! The sound is phenomenal ... utterly clean, utterly uncolored, no spurious resonances, superb transient response, outstanding imaging, and tight, unboomy bass with remark able extension for an enclosure approximately 38x20x23 in. There is no question that B&W has done a remark able amount of original research on this design, and the superb sound justifies all their efforts. I am hoping to get a pair of these 801 units before long and will report on them in depth.
I see that, with the best intentions to wrap up the SCES, I'll have to write a little supplementary report on some turntables, cartridges, and a couple of specialized items.
(adapted from: Audio magazine, Nov. 1979; Bert Whyte)
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