Kiss your analogue problems goodbye
One day we’ll wonder why we put up with reel-to-reel analogue tape for
so long. Here is a selection of classic analogue problems which the ADAT doesn’t
Newcomers to the recording studio find this noise intensely annoying, although
many engineers seem to be able to filter out it somewhere along the connection
between the ear and the brain. No matter how well aligned your machine, no matter
how flat the flanges of the spool, no matter how carefully you thread the tape,
that irritating rasping sound comes back again and again. If you try to correct
the problem by bending the flanges of the spool you’ll only make it worse,
and you may be tempted to adopt the solution many continental Europeans do which
is is to use spools without an upper flange. Be warned however that you have
to use European tape if you take a screwdriver to your empty take up spool because
the American stuff will throw its coils skywards when you fast wind.
Think of all the trouble you take to lay a nice clean signal down onto tape,
and then consider what happens when it is deposited on the rusty metal particles
of the tape’s magnetic coating. The result is that your lovely music plays
back mixed with a random signal which is commonly known as tape hiss. Tape is
a noisy medium, an order of magnitude noisier than high quality audio electronics,
and tape rather than any other component of the recording chain has placed the
limit on our achievements ever since it was invented. Things have improved vastly
over the years, particularly with the various forms of Dolby noise reduction,
but when you hear background noise on your finished recording, you can be sure
that most of it is coming from the analogue multitrack recorder. Digital recording
doesn’t eliminate noise, and really a digital multitrack recorder should
have a resolution of at least 18 bits to bring the finished mix up to full CD
standard since noise build up is inherent in any multitrack recording process,
but the 16 bit ADAT provides a very noticeable improvement on what most of us
are used to.
Tape hiss is one kind of noise, due to the fact that the signal is recorded
on particles of finite size. Modulation noise is something else, and arguably
more annoying – noise that rises and falls in level with the level of the signal.
Modulation noise makes a recording sound ‘dirty’ and is particularly
noticeable if you are recording without the benefit of Dolby noise reduction.
If you use dbx noise reduction, this has the effect (through a different mechanism)
of making the modulation noise worse. Digital recording isn’t totally free
of modulation noise, but at 16 bit resolution you would be really hard pressed
to hear any.