Marantz ST 6000 Tuner

Surf that air wave!

And in style, baby!

Product: ST-6000 FM/AM/LW tuner
Manufacturer: Marantz - Holland/Japan
Serial No.: M2000102002716
Price: app. $220 Euro
Reviewer: Dejan V. Veselinovic
Reviewed: September, 2001

Marantz st6000 tuner

What's this then, since when is TNT doing tuners? It isn't actually, it's just me being controversial again. Actually, I must confess - I'm a radio freak. When I was in the first grade, way back in 1959, on Saturdays I used to get up at 6:30 in the morning, go out to do my mother's shopping and have breakfast before 8:00, when there was a radio drama for kids, which I just never missed. That's how it started, with a Schaub-Lorenz radio, and went on to this day.

I don't know how radio stations are where you live, but over here, there are 63 active stations, each less than 10 miles away from me, some of which have such good sound, music selection wise and technically, that there's very little difference between them and listening to most home-orientated CD players in the economy range. Assuming, of course, that you have a decent tuner and at least a decent aerial. And I live in a densely populated urban area, in addition to which Belgrade is rolling on hills all the way anyway, which makes my reception conditions rather difficult at best. My arch enemy's name is Multipath.

Just a bit of background ...

In 1970-1980 era, tuners used to be bought on specifications alone. Everybody wanted great specs, especially the wrong ones, for not much money. Very few people knew what those specs actually meant and how they practically related to reception. In this, they were wholeheartedly helped by the audio industry, which was happy developing new interfrequency (IF) ceramic filters so they could get better selectivity figures, and some truly wild, but man oh man, WILD capture ratio specs were quoted.

This approach was shot dead by one man, one Mr Richard Sequerra. He started selling his legendary Sequerra 1 tuner (if memory serves) in early 70-ies, which lives on to this day as Day-Sequerra, in an improved form. He offered two versions, one with an oscilloscope instead of classic meters, and one without, the second one aimed at affluent aficionados, the kind of people who buy Krell and Levinson today. But the point was, his specs were rather different to the norm of the day, and it took some knowledge to realize that Mr Sequerra was, beside being a brilliant electronics engineer breathing FM instead of air, also a very practical man. He pumped his tuner where it really mattered, and was happy with less than brilliant specs elsewhere. I was lucky to be able to audition it in the late 70-ies, and I was shocked then, as I am in memory today, that a tuner could play such music. And that was then.

Since those days, we've come a long way. Very few audio technologies have made such excellent cost/benefit leaps forward as tuners have, and they are, in my view, unjustly overlooked today. No more sexy analog scales (tuner equivalents of suspender belts and nylons), all digital (pantyhose) today, but just like the ladies, so the tuners have also grown and evolved.

But let me say it outright - unless you know you have some decent radio stations you can pick up, don't bother with a tuner. If however you do have them within range, do think about a good tuner, these days they are cheap.

And so, we come to the subject of this text, the Marantz ST6000 tuner.

What it has

As most other Marantz models, so this unit too is available in champagne or black finish. My test sample was black, looking mean but not so lean. Its dimensions are 440x96x307 mm (app.17.3x3.8x12 inches) WxHxD, weighing in at merely 3.8 kg (app. 8.7 lbs) unpacked. With it, you will receive a (junk) stereo cable, an AM connection chord, an FM "indoor antenna" (actually just a piece of wire you throw somewhere and hope for the best) and an AM loop antenna. The instruction manual has all of 6 pages in several languages, but is relatively informative.

The front controls are many. From left to right, there's the power on/off switch, the antenna selector (1 or 2, LED indication, for FM only), IF selector switch (Wide or Narrow, LED indication), time adjustment (when turned off, the tuner acts as a digital real time clock), Station Name/Display selector, Tuning Mode selector (Manual or Fine), Tuning Up/Down buttons, Cancel button (if you make a mistake, and you will), the Next command (for more complex operations), Timer On/Off and Set buttons (so it switches off and on at programmed times), Preset Station Selector Up and Down, FM Mode (mono or automatic stereo), RDS switch and Band selector. You can memorize 30 stations for FM and 30 stations for AM for instant recall. Memory is internally backed up for about a week even if the tuner is unplugged from the socket, so you're pretty safe (look, mama, no batteries!).

Rear connections

At the back, beside the usual connectors for antennas, stereo output, etc, you will also find a Reset button - in case the tuner is hit by a voltage spike, thunder or a nuclear device, which might upset it and throw it into an epileptic fit, you might need to reset it.

The fascia is metal, and very nicely brushed it is too - the tuner looks like it costs about 3-4 times its actual price. It feels solid too, with its sexy brass side screws, a Marantz trade mark by now. The centrally located indicator window uses a dot matrix LED display, mostly in blue but some in red too, a necessity for RDS, which has to write out messages, not at all practical with classic 7 bar LED displays. But visibility is good, and lettering quality is what you would expect of such a manufacturer, very good.

Technology, Specifications

The above Mr Richard Sequerra started out as a young engineer in this very company, Marantz; of course, in those days, it was still owned and run by the late and much lamented Mr Saul Marantz himself, one of The Greats. It seems fitting then that this odd one out text be dedicated to a company which did very much for tuners in general in its golden days.

The tuning range is the common 87.5-108 MHZ. The 30 dB S/N ratio in mono is achieved with just 1.2 micro volts, a very good result. THD at 1 kHz is quoted as 0.08/0/15%, but without mentioning whether this applies to FM wide or narrow selectivity, so you should assume it's for wide. Selectivity is switchable between 65 and 80 dB; the 15 dB difference really means 5.6 times more, both good figures, but I must say having 65 dB as wide is more than just good, it's unusually high, and in real life, you won't be needing the narrow selection too often. Frequency response is quoted as "20 Hz - 15 kHz, +1, -3 dB", which is good but nothing special. Image response is gives as 70 dB, a borderline value between three and four tuned circuits (more is better); in practice, I suspect this is a very conservative figure, since the front end does have four tuned circuits.
AM suppression is quoted as 55 dB, a good value, but not outstanding, and this is a very important capability for urban area tuners worth their salt. Signal to noise ratio, always a problem with tuners, is given as 80/75 dB mono/stereo, both excellent figures. Finally, stereo channel separation is given as 50 dB, a very good value indeed.

So far, so good, but some specifications are not mentioned at all, and I regret this. Notably, no capture ratio is provided (I assume due to available selectivity choice), and no pilot tone (19 kHz) and subcarrier (38 kHz) suppression are mentioned. These two can cause "birdies", a sound like birds chirping, if not efficiently cut, not unlike the need to filter CDs at above 22 kHz - now you know how the CD guys learnt their trade, from FM. Marantz does mention in their literature that they have an "anti-birdie filter" installed, and frankly, I didn't experience any problems, but I'm still unhappy about lack of specs.

Inside the st6000

As for the technology, what you get is fairly mainstream, but mainstream done well. I saw two ceramic filters in the IF strip and one in the AM/LW section. The Dual Gate MOSFET front end is, as usual, a buy-in item from a third party. I counted 24 discrete transistors (in addition to several ICs) in the FM section. The analog output section consists of one NJR 4558 dual op amp, unfortunately in a single-in-line package, so changing won't be easy (but still possible).

The power supply section uses two three point stabilizers by Motorola, for +5 and +15V. This is filtered by a 3,300 uF capacitor, preceded by a discrete diode bridge rectifier, with the diodes properly bypassed by small value capacitors. All in all, classic, but solidly done technology.

Reception

Well, testing a tuner is really hard, but also much fun. I have tried reception from a total of seven locations in the 2.5 million people strong city of Belgrade. Depending on the location, I experienced less or more trouble with the reception, as I kept changing my location relative to the station's broadcast aerial, but this was less than I expected. In all cases, and in order to equalize the conditions as much as I could, I used an active indoor antenna, with an effective gain of 22 dB (app 12.6:1). I suspect this is how most city dwellers will probably use it, though I urge one and all to go for a decent outdoor antenna, preferably rotating. Not all of us are going for digital radio yet.

ST6000 helped me there with it signal strength meter, expressed in dB, though there's no mention what's the 0 dB reference point. Nevertheless, once you're above 40 dB (100:1, whatever the "1" is), you have no noise to worry about any more.

In most borderline cases, all I could do was switch the selectivity from wide to narrow, and in most cases, this helped. When it didn't, the signal strength was usually very low anyway, and there was too much noise to allow listening.

All in all, I'd say this was a good air wave catcher, which refused to be put off with reception problems. In fact, in view of its relatively modest price, I'd say it put in a very fine performance, definitely above expectations - and the norm.

Microdynamics

There's a local station which plays my kind of music, so it's no wonder our musical tastes coincide. It's even less wonder, then, that I used it as an auditioning reference point, since there was many a time they played music which I have on my own CDs. This is good, even necessary, for any serious listening.

I was rather pleasantly surprised by what ST6000 offered me, which was a sound very near in quality to what I get at home. Fine details came across rather well, though some of them were lost along the way - no wonder, when you consider what happens in between the radio station's player and my speakers. But the overall loss of fine detail was considerably below what I expected at this price point.

Vivaldi's "Four Seasons", for example, lost a little of their ambience, but the entire structure of the music was there, and much more important, the passion was almost untouched. I'd like to say "totally untouched", but obviously, I cannot, some nuances were in fact lost. Yet the overall feeling of the piece was there, hardly touched at all, perhaps a little shifted across the spectrum, with a touch more prominent bass than is really needed.

The usual failing of tuners, poorer performance above 10 kHz, caused by sharp pilot tone (19 kHz) and subcarrier (38 kHz) filters, was fortunately not noticeable; percussion came across in most of its glory, though it was a little dulled, losing a bit of its expected sting. Yet, for all that, I would say this was an above average performance overall.

Macrodynamics

Much the same as above. This tuner gives little by way of sound quality, though it can't compete on a head-to-head basis with a good CD player. Hardly surprising, I'd say, but the real question is how much does it leave out? Well, very little, again, surprisingly little.

I had radio program blast away in the house, courtesy of my Karan KA-i180 and AR94, and it sounded good, it sounded like music I could leave on playing interminably. Rock and modern music fared especially well, and believe me, at the levels I was hitting, I would have heard any serious distortion, especially multipath and AM, if it came my way. I'm not saying there was none, but what there was, was low in level and quite unobtrusive.

Fortunately, somebody decided to play the entire CD of a newly released percussion quartet; my love for percussion is well documented, and I heard some very thundering and most convincing sounds (as did my neighbors). 55 minutes of pure drum kit, with tons of adrenaline, showed the Marantz in a really good light. The staccatos were especially impressive, clean and well defined.

The Ultimate Test

For all that, the ultimate test of a tuner is to take him to a lab which has an FM modulator, connect the two, and try A/B tests via the modulator and tuner on one side, and directly into the amp and speakers on the other side. I don't have that equipment, but I know who does, and fortunately, we are on excellent terms, so a session was arranged.

That's when the Marantz ST6000 really impressed me. Listening to radio stations introduces variables one is not even aware of, like what the DJ did to his graphic or parametric equalizer, what kind of equipment they have, how good is it, that sort of thing. But an A/B test via a modulator is most revealing regarding the tuner's true abilities.

Here, I was downright impressed by the Marantz. It did show up some slight faults too. Its high frequency range was a little below par compared to a straight CD player, a function of, I think two things: 1) its pilot tone and subcarrier filters, and 2) the op amp in the output stage. It's arguable whether one needs a high quality, super fast op amp when one's bandwidth is by default limited to 15 kHz, after which one must start to filter very sharply however you look at it, but then, high speed op amps will still deliver their goods with less distortion, even if their speed is actually wasted.

But the sound was vibrant, alive, not sterile as in lesser units, washed, even stripped clean of any and all emotion. It had its faults, but these were mild in nature, partly unavoidable, and only partly recoverable by still better design. Perhaps using superior components would have improved matters, but they would have hiked the price up rather considerably, still leaving the variables of the radio station unresolved.

Overall

Marantz' ST6000 tuner is a very impressive piece of kit. It has a slight loudness-like response, tending to accent the bass a little in comparison with the treble, but this could just as well be very linear low range and slightly depressed high range, caused by the need to filter out the pilot tone. Nevertheless, this is an extremely listenable sound, with a bit more warmth than is absolutely needed.

Its wide selectivity is 65 dB, an uncommonly high value, which is, I believe, its probably greatest asset. To get low distortion figures, manufacturers drop this down to the 40-45 dB range, 10 times lower, and for difficult reception, they hike it up to 80-85 dB. Marantz is to be congratulated for selecting 65 dB as its wide selectivity option because this is high enough to offer good selectivity to the point where you will rarely need to switch to narrow and its 85 dB value (10 times more). I do believe this is where a rich history of tuners shows up, a history few, if any, can match.

I regard RDS functions as relatively unimportant, since they were introduced for motorists rather than stationary tuners, but that said, I must admit Marantz has implemented them in a commendable way. You can have all the information you want, and sometimes, it can be very helpful; while skipping the air waves, I caught a pop song I never knew who played it, and was informed by the display of the performers. Touché.

This is Marantz' better tuner (ST4000 is the cheaper variant), though they offer still better higher up in the range. I would describe ST6000 as the sane audiophile's tuner - it does what it is supposed to do better than expected or led to believe for the modest price. It has its faults, but they tend to pale in comparison with its virtues.

I'm not going to say that it sounds now as the original Sequerra did in its time, but I am going to say it shows how far the art of tuners has come after all these years - very far indeed. I'm not sure I'd dare listen to Sequerra's offering today, I'd probably be sick for a week for not being able to afford it.

If you want a tuner which will spare you the plasticky sound of most cheaper units on the market today, including products from some famous names, look no further, Marantz ST6000 does the job. More than that, it does the job considerably better than you would expect it at its price point. In tuner terms, it is a bit more than the lowest tier, but the performance is way above that level.

In short, ST6000 offers an outstanding price/performance ratio. Its FM section is as good as they come for the money, and for more money than you are expected to pay, while its analog output section is way above the price norm, despite the slight loudness effect. It's not an audiophile sound quality, but it is above average Hi-Fi quality, where "Hi-Fi" truly stands for High Fidelity. Well done, Marantz.

© Copyright 2001 Dejan Veselinovic - http://www.tnt-audio.com
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