How To Choose A Good Tuner From The Bad
Choosing a tuner for your system is of little difference from
choosing other components. When auditioning other components,
people are primarily concerned with their sound quality, not
their technical performance.
For example, if a preamplifier under audition sounds good, you
do not need to worry much about its technical performance.
Because .if it sounds good, then it is working well.
Tuners, on the other hand, exhibit great variability in their
technical performance. It will not only concern the tuner’s
sound; tonal balance, sound staging, portrayal of timbre, etc.,
but also basic characteristics such as the ability to pick up
weak or distant stations, reject adjacent stations, provide a
noise-free audio signal, and stay tuned to a station without
drifting.
A tuner’s performance in these areas can be accurately
characterized by measurement; this makes tuner specifications
much more significant than those of other audio components.
There is a direct correlation between a tuner’s specifications
and its sonic performance. You still have to listen to the
tuner before you buy, but you can often separate poor
performing models from better units by looking at the
specification sheets.
Unlike most audio products, the best high-end tuners have more
features, front-panel controls, and displays than the lower-end
products.
The price range for a good tuner from a mass-market
manufacturer is between $400 and $1000. Some of the higher-end
models from mass-market companies offer excellent performance.
The price range from $750 to $1200 is very competitive, with
many superb units to choose from. The very best tuners cost as
much as $12,000.
The differences between mediocre and excellent tuners.
Good tuners are characterized by their sensitivity or the
ability to pull in weak stations. The greater its sensitivity,
the better it can pick up weak or distant stations.
This aspect is more important in suburban or rural areas that
are far from radio transmitters.
On the other hand, a tuner characteristic of greater importance
to the city dweller is adjacent-channel selectivity or the
ability to pick up one station without interference from the
station next to it on the dial.
This specification defines a tuner’s ability to reject a strong
station two channels away from the desired channel. When
stations are packed closely together, as they are in cities,
adjacent-channel and alternate-channel selectivity are more
important than sensitivity.
Equally important to all listeners is the tuner’s
signal-to-noise ratio, a measure of the difference in dB
between background noise and the maximum signal strength. A
tuner with a poor signal-to-noise ratio will overlay the music
with an annoying background hiss.
A poor tuner will have trouble receiving weak stations, may
lack the ability to select one station when that station is
adjacent to another station, have high background noise, and be
overloaded by nearby FM transmitters or other radio signal
sources.
Many tuners have a high-blend circuit that automatically
switches the signal to mono when the signal strength falls
below a certain level.
The difference between high-blend and the mono/stereo switch
just described is that the high-blend circuit puts only the
treble into mono, leaving the rest of the spectrum in stereo.
This gets rid of most of the noise, but maintains stereo
separation through most of the midrange and bass.
Lastly, all good tuners have a 75-ohm coaxial antenna input as
well as the more commonly used 300-ohm flat-lead input. The
coaxial input should be used for best signal transmission
between the antenna and tuner.