For the Record: Choosing
Equipment to Play Your Vinyl
The inclusion of record-playing equipment in a
high-quality audio system is pretty much a rarity these days, except perhaps for those
diehards who believe that digital audio is inferior to traditional technology. Vinyl is
capable of extremely high performance under the right conditions, to be sure, but whether you
need record-playing capability or not, and the specific sort of equipment that is right
for you, depends on a number of factors.
If you have only a small number of favorite LPs, for
instance, it may make sense to copy them onto cassettes or recordable CDs and abandon the
LP format altogether. In that case, you may already have a turntable of some sort, and it
can be used to make the transfer (although a new cartridge may be a good investment, even
for just the dubbing process).
If your vinyl collection is large, however, it is probably
impractical to copy all of it; doing so would involve some sacrifice in quality in any
case, so maintaining equipment to play the originals is probably the best policy. That may
mean upgrading only parts of it -- the stylus, say, or the whole cartridge -- but in many
cases the best thing is to trash what you have now and upgrade to equipment that's as good
as you can afford, while there's still some variety to choose from. Once you do, both your
equipment and recordings will become increasingly irreplaceable, and should be cared for
in that light.
Squeezing a high-quality audio signal from a piece of
molded plastic is an improbable process, fraught with difficulty, so perhaps it's fair to
suggest that everything to do with the record-playing chain matters. But in
reality, only a few things vary enough to be useful when it comes to making a buying
decision.
One thing that's usually advisable is to lavish some care
on the device that actually reads the record's grooves and creates an audio signal: the
phono cartridge. Many vinyl fans swear by moving-coil cartridges, and some of these are
superb, but they can be a liability. The stylus will inevitably wear, and with moving-coil
models, that usually means a trip back to the factory. That may be practical today, but if
the company gets out of the cartridge business, you may not be able to do that in the
future. Better to buy a moving-magnet design and at least one spare stylus that you can
install yourself.
Also bear in mind that a turntable can't simply be plugged
into any input on your amp or receiver, like a cassette deck or CD player. It requires an
extra layer of processing by a phono equalizer. Newer equipment may not have this
built-in, so you'll either have to pick a receiver that does, or buy an outboard phono
preamp that can be fed into a high-level input.
Otherwise, the equipment that plays records is almost
entirely mechanical, electricity coming into play only to drive the motor and at the last
stage, where the physical motion of the stylus is turned into an audio signal. It stands
to reason, then, that mechanical performance should be your first concern. Speed
irregularities -- wow and flutter -- are not uncommon in turntables, so you should look
for specs between 0.1 percent (which is sometimes audible) and 0.05 percent (which rarely
is). Whatever the numbers, check things out by playing a record that contains sustained
piano notes; if they sound slightly sour, as if the piano needed tuning, there's too much
flutter.
Mechanical vibration from the motor can sometimes creep
into the output signal in the form of rumble. If you can hear it during quiet passages or
between the silent bits between tracks there's obviously a problem in this area. Even if
you can't hear the rumble, however, it still has the capacity to use up precious
amplifier watts. Often it will show up on your cassette deck's meters when you make a
recording, or even on your amplifier's output indicators during quiet passages. It's even
possible to see rumble by taking the grille cloth off a speaker and watching the
woofer move in and out silently. Likewise, isolation from external vibrations can be
demonstrated by gently tapping the turntable base and the table it sits on and listening
to (or watching) the results.
At first glance, it may seem reasonable that contact with a
record's surface be kept to an absolute minimum. That's probably true when it comes to
potential surface damage, but firm support is needed over the whole playing area for best
performance. If an LP is allowed to flap in the breeze, it will easily pick up airborne
vibrations, including what's coming out of your speakers, and this will be conducted to
the phono cartridge. The cartridge can't distinguish between groove undulations and disc
vibration, so whatever the record picks up from the air will be amplified, leading to
extraneous noises or, in the worst cases, acoustic feedback.
The solution is to support a record in the playing area but
not at the raised edge or label. If the mat on the turntable you want to buy doesn't do
this, replacement mats are available that will, but they are useless with devices that
provide support at only a few points.
The usual audio criteria -- flat frequency response, low
distortion, and so forth -- do apply to record players, but because electromechanical
devices tend to produce higher numbers, phono-cartridge makers usually publish few specs,
so you have to rely largely on your own experimentation. Try playing a record with a fortissimo
ending that occurs in the inner grooves of a disc; if the cartridge can handle that, it
will probably be able to track anything (but beware: if it can't track the test
passage it might damage your record).
Also arm yourself with a severely warped record, and check
it out in the store. Make sure that the cartridge/arm combination is exactly what you are
considering buying because how the two parts interact has a lot to do with their success
in dealing with warps.
During all of this, note how easy or awkward the turntable
is to operate; like a cassette deck, a record player is something that has to be operated,
so ease of use is a prime consideration.
The cartridge/tonearm/turntable combination is made up of
many disparate parts, some electrical, some mechanical, and in each case the designer has
a wide range of options in accomplishing a particular goal. Which ones he chooses rarely
mean anything to the ultimate buyer.
In early audio, for instance, it was an axiom that a
turntable should be as heavy as possible so that it would act as a flywheel and smooth out
speed irregularities. It's still possible to buy turntables designed with this principle
in mind, but they have no monopoly on smooth rotation; most turntables today, even modest
ones, boast very good wow-and-flutter performance without resorting to sledgehammer
construction techniques. They also have the advantage that most equipment shelves can hold
them and that they don't take five minutes to get up to speed.
Except perhaps for flipping an LP over, turntables can be
made to do virtually anything automatically, from lifting the arm to shutting down the
whole system. It all costs money, and is designed to simplify a process that isn't
difficult. Semiautomatic tables don't do everything, but probably do more than you need.
The only thing that's really helpful is some method of lifting the stylus at the end of a
side, so your system doesn't emit an extended k'shish . . . k'shish . . . k'shish
while you dash in from the next room. Otherwise, stick with a manual table.
Cartridge makers are wont to boast of high separation (or
low crosstalk -- the same thing), and certainly the greater the number the better. But
studies have shown that there only need to be about 20dB of separation for perfect stereo
imaging, so anything more than that is a poor basis for choosing a cartridge.
There are lots of different ways to construct a turntable
or a cartridge, and historically some of them have yielded better performance than others.
But that's rarely true today: it hardly matters how the designer gets the platter to
revolve or extracts the music from the LP and gets it to your preamp. There are sonic
differences between components, to be sure, but these mostly have to do with how well they
are constructed rather than what engineering choices the designers might have made.
...Ian G. Masters
ian@mastersonaudio.com
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