Friday, October 29, 2010
Marantz 20B Sweet Rockin' Bad Boy
My Marantz 20B definitely has more personality than the average tuner; it has a Bad Boy attitude. But it does sound sweet, particularly on strong commercial Rock n' Roll stations which might seem unlistenable on a geeky tuner like McIntosh MR 78.
It doesn't work for the local classical station, my favorite station, it suffers even more from subcarrier noise, or something like that, than most tuners, so it's somewhat too noisy for seated listening, in addition to projecting the usual birdie I get from this station on most tuners. With the Marantz, the birdie is localized outside the speakers, out-of-phase. Low compression classical music also exposes noise much better than highly compressed Rock. The modified Sony XDR-F1HD is the only tuner I have which gets this station perfectly, though modern digital tuners like Yamaha TX-1000 suppress the noise and birdie so well you have to get up to the speaker to hear it. Analog tuners always get this station with some noise, but the 20B may be the noisiest I've tried so far, not that it's super noisy, but just noisy enough not to be fully satisfying. I could enjoy this station on a Kenwood KT-8300 despite its noise, but the 20B just goes a bit too noisy. It will be interesting to compare it with tube tuners. I would not be surprised if some tube tuners actually sound quieter.
It works much better for a slightly weaker college Jazz station (which ironically has an actual HD subcarrier which creates no birdie), but still does nothing special like it does for Rock.
It totally enhances rock stations with a nice bass which seems to go underground (is it boosted?) and liquid mids and highs. In the mids and highs it sounds a lot like tube tuners (and also has a rather laid back sensitivity curve like they do, hence the noise level on weaker stations). There's also a kind of loosey-gooseyness that seems to open up the sound on otherwise highly-processed commercial stations. The over-processed sound seems less processed and predictable. I sense there is a kind of over-arching transparency that comes from the very wide bandwidth, but other than that this tuner seems more "musical instrument" than "precision instrument", and may also achieve some of its enhancement of rock stations through selective coloration and obscurity rather than the highest transparency. Whatever, it works on commercial rock stations.
Listening through the noise to the classical station, I think I can also hear a bit of distortion which is somehow not audible on rock stations. This 40 year old 20B looks untouched and after that many years, it's amazing it works at all, and like any tuner of this age, it certainly needs to be refurbished and aligned. Perhaps that will make it cleaner and quieter? No, undoubtedly alignment will make it cleaner and quieter, but how much?
Anyway, right now it's a tricked out low rider car with fancy hydraulics and squeaky springs, just what you need for Rockin'. Let me count the ways it shows attitude:
(1) Electrical leakage. First plugged in, I felt a tingling from fairly strong leakage from the faceplate, though probably not bad enough to cause injury. So I reversed the plug, a procedure all audiophiles from the 1960's are familiar with. At first, this seemed to kill the leakage completely. Then I noticed it's still detectable if you rub your finger along the edge of the front panel. If you hold your finger down, you feel nothing, so this is very small leakage, not dangerous, but noticeable. This unit from 1970 has no grounding plug, if it were sold today it HAVE to be grounded, and then you wouldn't notice any leakage (but you would instead notice an annoying hum from the ground loop). So, the Bad Boy gives you freedom from hum but leakage instead.
(2) Interstation WHAM! Unfortunately, and in contradiction to what the eBay seller said, the muting on my unit does not work. Between stations, there are noises strong enough to rattle and blow your woofers if you are not careful. It's like the usual output voltage is 1V but the interstation noises are 7V. (This is a guestimate based on the LED's on my Lavry, not an actual measurement yet.) But if your system has tons of headroom, like mine, it's fun to twirl the dial and shake the whole room. Who needs actual music? There's no volume control on the front panel either.
(3) Ringy chassis. The chassis is nicely made out of very solid metal. It rings nicely when you hit it. So don't hit it. Or hit it with rhythm.
(4) No stinkin' meters, man. Yeah it's got a scope. Not really a big enough scope IMO, the 10B and Marantz 150 had larger scopes, but it's better than no scope. The combination of scope and very wide IF bandwidth is a license to off-tune. When you have meters, it's like you have a little geek telling you "tune here or else." With a scope, even if not adjusted, you see what's happening in the IF, and you see where the ultimate detection limits are, but not so clearly where the exact center is.* So you just tune it "in there" and it works. By the way, since this is a very wideband tuner, perhaps the widest band tuner I own, the detection limits are waaaay out there. And somehow they arranged it so the stereo decoder works all the way to the limits. In fact, it may be broken in my unit, my unit never seems to go to mono (judging from the sound, actually my Stereo light never comes on, may be just burned out or something worse).
*That's the way the most useful scope display, "multipath" works. Now unlike the earlier Marantz 10B, the 20B also has a "tuning" mode to the scope display. That changes the line on the scope from horizontal to vertical and you tune so that the vertical scope line appears inside the bullseye. That's an extremely boring display so I tend not to use it. Also, it turns out it isn't accurate anyway unless you calibrate it first. To calibrate (I discovered this without reading the manual) you run the dial pointer all the way past 108. That seemingly forces the scope line to its intended center. Then you adjust the vertical and horizontal controls as required. That whole procedure seems Bad Boy to me, especially turning the dial past 108.
There's also a Left Channel vs Right Channel vector mode to the scope display. If you're wondering what your stereo separation actually looks like, there it is. Now real bad boys keep their Marantz 4400 receiver scopes set to the vector mode, because it is also "light show mode". I've seen blogs where no bad boy present actually understood the other scope modes.
Marantz has decided not to give you an intensity control for the scope. They don't trust you quite that much. Anyway, the intensity was just fine, I thought of turning it down a bit to preserve scope life, but couldn't. A Bad Boy certainly wouldn't bother turning it down, only up.
Most analog tuners that I've come across have had malfunctioning center tune meter anyway. They never seem to be tune best at the center of the meter because the meter itself is off. So allowing (even forcing) you to calibrate your own scope meter allows you to make sure it's always right. Or always wrong. Who knows if you can really trust the "past 108" tuning calibration voltage? Anyway, given this kind of functionality, you could also adjust the center tune to whatever you want, whatever works for you, Bad Boy, even if it's a particular amount of off-tuning.
(5) Don't mess with adapters, just cut the RF cable. Now perhaps this can be excused since this is such an old tuner, but I've always been annoyed at tuners and receivers that don't give you a proper F connector for your 75 ohm coax. Marantz kept up this for quite awhile, the Marantz 2270 receiver I bought in 1974 also had no F connector (and worse, that one had lousy spring terminals) . I'm not quite sure when Marantz started putting F connectors on their equipment, I think the Model 2130 from 1976 had one, but it seems like Marantz was bucking the trend here for quite awhile. Why?
Well possibly because it's actually cheaper and easier to do things this way, unless you're worried about re-using your cable later. Bad boys don't sweat such details. Run the cable in from your antenna, and then Marantz gives you license to cut the cable at the exact length required to reach your tuner. Then get out your big old slotted screwdriver and screw it down. This one has nice big screws.
Back in the 1970's I used to worry that kind of connection was not good for the 75 ohm characteristic impedance. But it's probably doesn't make much difference for a half inch of bare wire.
Once you've done this, of course, you are not going to go back to that other geeky tuner with an F connector, like a McIntosh MR 78. But you weren't planning to do that anyway, were you?
(6) Right on top, left on bottom. Most audio equipment has adopted the convention of putting left channel on top, right channel on bottom. Marantz puts right channel on top, left channel on bottom. For decades my conspiratorial mind has been pondering if there is some kind of political significance to this. But even if it wasn't an attempt at making a political statement, clearly Marantz was bucking another trend. Also, annoyingly, the channels are labeled A and B on a big label. You have to read a smaller label to see which is intended to be right and left.
Now there are lots of bad boys in audio. Here's a short list: Dick Sequerra, James Bongiorno, John Curl, Dan D'Agostino, Nelson Pass. These are the kind of guys who give you want you want, even if it's over the top, ignoring the nannies who say you don't need it.
And now I can see I'm a Bad Boy too, and I like this Bad Boy tuner for what it does best.
[Disclaimer for geeks: this is a "first impression" review from my first night of listening. No measurements or A/B tests were performed.]
Posted by Audio Investigator at 3:30 PM