FM Tuners: A Hopeless Dilemma for the Serious Audio Reviewer (Vol.2, No.2: 1979)

FM Tuners: A Hopeless Dilemma for the Serious Audio Reviewer: NAD 4080; Sequerra Model 1; Series 20 Model F-26; Yamaha CT-7000.

A dependable evaluation of FM tuners from the audio purist point of view appears to us at the moment to be both unfeasible and irrelevant. Nevertheless, we report what little we've found out about just a few interesting tuners.

The central fact of the present-day FM scene is that nearly all stations are broadcasting a signal of inherently poor audio quality, not much more enjoyable when received with an excellent tuner than over the kitchen radio. Most of the music is on beat-up LP records, played with inferior pickups misaligned both laterally and vertically; the occasional live broadcast is likely to be carelessly microphoned with second rate equipment. So the first and most obvious question is- why would anyone want to buy an expensive FM tuner of audiophile caliber to listen to this junk? The best answer we can expect is that a few metropolitan areas in the country-maybe three or four-each have one good-music station that worries about audio quality, but even that isn't a good enough answer. We have perhaps the best such station, WNCN New York, about 18 miles from our antenna, and we can tell you that the same records sound incomparably better when played on our Reference A system than when received from WNCN via our Sequerra Model 1 tuner plugged into the same system. Why? Because no FM station, not even the fussiest, uses top-notch moving-coil cartridges with line-contract styli (not rugged enough for back-cueing by DJ's), and no FM station tunes the VTA separately for each record, even if the tone arm is correctly aligned for lateral tracking geometry.

We don't consider the sound of WNCN to be sufficiently transparent and focused to serve as a reference in determining the limits of a tuner's ability to resolve audio information and in making meticulous A-B listening comparisons. Not that it isn't a good enough sound to permit some tentative conclusions (see the brief reviews below), but the confidence level just isn't the same as in our preamp comparisons, for example. We hardly need to add at this point that, without such listening tests, all bets are off; tuners are subject to the same elusive time-domain distortions as other electronic devices in the signal path, and you already know how far black-box measurements on the lab bench get you in looking for these things. So, just for openers, FM tuner quality is both academic and inscrutable, at least under the present circumstances.

It has been suggested that a reference-quality audio signal, out of a preamp or a tape deck, could be fed via an FM signal generator directly into the antenna terminals of a tuner under evaluation. That would certainly eliminate any possible objection to the program source; unfortunately, real world conditions aren't duplicated by such a listening test.

One of the most important requirements in an FM tuner is that it mustn't act as an AM tuner. All AM, including multipath, must be rejected as sharply as possible, otherwise it will confuse the FM detector and impair the sound. This crucial aspect of clean FM reception isn't tested at all when the front end of the tuner is driven from an FM generator. The winner in this kind of listening comparison could conceivably be a loser when the roof antenna is connected. Incidentally, one of the most common shortcomings of routine FM tuner testing on the lab bench is the lack of attention to AM rejection. Sometimes it can be the whole ball game.

Maybe what we should do is to rent a local FM station with a good transmitter during the night hours when it normally doesn't broadcast, drag the phono and tape components of our reference system there, and run a listening comparison of tuners in our laboratory. That would probably work. Frankly, we don't think it would be worth the effort, even if they allowed us to do it. We'll wait until the average quality of FM broadcasting improves a bit. Meanwhile, here are our impressions of a few tuners, old and new, on the basis of A-B listening comparisons using WNCN and other local stations as the program source. We doubt very much that we'll do this again in the near future.

NAD 4080

NAD ( USA), Inc., New Acoustic Dimension, Mackintosh Lane, PO Box 529, Lincoln, MA 01773. Model 4080 AM/FM Stereophonic Tuner, $285. Two-year warranty. Tested #4806152, on loan from manufacturer.

This is from the same people who make the astonishing y good low-priced integrated amplifiers reviewed elsewhere in this issue. The 4080 is their top-of-the-line tuner (yes, the others cost even less); like all NAD products it's made in Taiwan, of unimpressive parts that are nevertheless of reasonably good quality in strategic places. The construction and cosmetics are well above expectation in this price category. Lots of features, too, including multipath indicator and switchable Dolby equalization (though no decoder).

In direct A-B comparison with our Sequerra Model 1 reference tuner, the NAD sounds a little less transparent, with inner detail not quite as airy and sharply defined. It's also a bit noisier. All in all, however, the difference is amazingly small, even to the point of inaudibility on some program material. We don't see why anyone would need a better tuner than this, except possibly to tape record the one or two lives broadcasts a year that are genuinely clean. The 4080, like most good tuners, is still heavily overqualified for the job of faithfully reproducing day-to-day FM garbage.

Sequerra Model 1

The Sequerra Company, Inc., 143-11 Archer Avenue, Woodside, NY 11435. Model 1 FM Tuner, $3600. Five-year warranty. Tested #1022, owned by The Audio Critic.

Still the acknowledged ne plus ultra of FM tuners after all these years, despite its lack of quartz-locked tuning and other newfangled wrinkles, the Sequerra Model 1 survived Dick Sequerra's departure from the company bearing his name and is made today pretty much the same way as ever, except perhaps without Dick's fanatical attention to alignment.

A full description of the tuner would take pages and is probably unnecessary in view of its long-standing reputation; we still chuckle, though, whenever we use its “panoramic display.” which is actually an RF spectrum analyzer. The legend is that this started as a joke; somebody said to Dick, “Come on, what can you possibly put into a tuner for that kind of money-a spectrum analyzer?” and Dick said, "Yes!" Then he just had to do it and figure out some justification for it. But he also put all sorts of other good things into the tuner, and it all works very nicely. We own the 22nd one ever made, and it has never given us any trouble.

Sonically the Sequerra is a small cut above any other FM tuner known to us; it's just a little cleaner, more trans parent, better focused, more detailed on top, and quieter than the others. But the difference isn't dramatic; it's audible only on truly exceptional broadcasts. In fact, most of the people we know who buy Sequerra tuners aren't typical audiophiles but obsessive elitist perfectionists who can't stand the thought of anything but the best. Like us.

Series 20 Model F-26

Series 20 (a division of Pioneer Electronic Corp.), 85 Oxford Drive, Moonachie, NJ 07074. Model F-26 FM Tuner, $1000. Two-year warranty. Tested #YF3600195M, on loan from manufacturer.

Very much in the contemporary Japanese high-end tuner idiom, the F-26 is beautifully built, elegantly functional, highly automated, with quartz-locked tuning and all that jazz. In A-B listening comparisons, however, it doesn't quite measure up to the Sequerra Model 1, sounding just a bit more constricted overall and less wide-range (or call it less fast and defined on top). The Yamaha CT-7000 also appears to be marginally superior to it in these respects. We can't get too excited about the differences, though; the F-26 is still a very fine tuner in a world of lousy FM stations.

One feature that gave us a little trouble is the automatic (and undefeatable) switching between wide and narrow IF passband, designed to track the incoming signal quality as sensed by the tuner and provide optimum audio quality at all times. The circuit can occasionally be fooled by irrelevant phenomena such as, for example, the presence of an SCA subcarrier. The switching between the two IF bandwidths is accompanied by a click, which can ruin tape recordings, among other things, if it comes in the middle of the music.

This erratic behavior is probably the only negative aspect of what is otherwise a very slick little FM tuner.

Yamaha CT-7000

Yamaha International Corp., 6600 Orangethorpe Avenue, Buena Park, CA 90620. Model CT-7000 FM Tuner, $1200 (price as of late 1977, unit no longer made). Tested #1735, on loan from owner.

When this tuner first appeared on the scene, it was hailed as the only possible rival of the Sequerra Model 1, at a fraction of the price. Some even claimed it was indistinguishable from the Sequerra in audio quality and a number of other respects; a few said it was actually better. Our A-B comparison indicated a IND (just noticeable difference) in favor of the Sequerra, but as we pointed out these FM listening tests aren't very rigorous. The Sequerra appeared to have just a shade better top-end definition, transparency and dimensionality, but it was by far the smallest and most elusive difference in any of our FM tests. On indifferent program material the two tuners sounded absolutely identical.

Some time ago, the CT-7000 was discontinued, but there are always a few of them being traded in the second hand market. Ata good discount, we'd say it's an unbeatable bargain. Meanwhile, the Sequerra is hanging in there as the sole representative of unmitigated overkill in FM tuners, and just one of those is more than enough in our opinion.

Recommendations

None. Why would you want to buy expensive new shoes when all the streets in town are unpaved and muddy? Use whatever you have or whatever you can get cheap. Or pick one of those reviewed above, if it intrigues you. When it comes to FM the way it exists in the U.S.A. (quite aside from its inherent potential), the reaction of The Audio Critic is to walk away from it.

---------

[adapted from TAC]

---------

Also see:

Yes, Preamplifiers Are Still Getting Better All the Time: Audionics RS-1 ; Audire 'Legato' 535; Bauman PRO-400 ; Hegeman 'Hapi Two' ; Precision Fidelity C7 PS III and PS LCC

Why We're So Mean, Vindictive, Arrogant, Negative--and Truthful

Various audio and high-fidelity magazines