I would like to comment generally on today's noise-reduction software
for putting records on CD.  I speak mainly about the cheap or free
utilities most of us will end up using (mine came with an old copy
of Cakewalk Pyro).  These programs can offer amazingly good results
without a steep learning curve or high expense.  They can also put
your record in a sonic fish tank (especially if you use the default
settings!).  Maybe these thoughts will save somebody some work.

The utilities I have seen fall into four categories:  Tick-and-pop
removers, "crackle" removers (intended to reduce a dense hash of
ticks), hiss removers, and equalizers.  My experience has been as
follows.

The tick-and-pop remover is the most foolproof utility.  It is very
effective at removing isolated ticks even when set at a moderate
level, and produces no audible side-effects at all.  It will even
remove digital clicks from files with poorly-done edits.

The crackle remover is the second-most benign tool.  It can produce 
a dramatic improvement to 78's, and can even strip away inner-groove
distortion and mistracking when your LP-cartridge is not performing
flawlessly.  It can be used fearlessly with any kind of music that has
no percussion or brass.  But even used moderately, it will turn a snare
into a shoebox and a cymbal into a pie-plate.  It will erase the bright
growl of brass instruments played loudly.  All this illustrates why we
must not merely listen to the noise, but listen just as closely to the
music.

I often find there is a happy medium (often a very low setting, say,
8%) at which the crackle remover smoothes out distortion but leaves
musical "noise" intact.  I was amazed once when a very shrill set of
78's was beautifully smoothed out when its _musical_ content was beat
into shape by a high setting (65%) of the crackle remover.

The hiss remover is the nuclear bomb.  At even a low level, it
interacts greatly with the hiss in the program, giving results that can
be spectacular (noise gone, music intact) or fatal (blurry swirlies
like Darth Vader).  It consists of two controls, one of which specifies
how low you want to send the noise (I _never_ set this control higher
than 15 dB), and another which specifies how much noise you want to try
to remove (I never set this control higher than 35%).

When percussion is well-recorded, my hiss remover is useless -- it
destroys the high end.  When it works well I must walk it through its
useful range and find the spot where the dropping original noise
begins to be overtaken by unpleasant new artifacts.  The place where
the remaining noise just barely masks the encroaching digital swooshing
is the desired setting.  I am convinced, listening to the amount of
hiss being left in transfers by Ward Marston and other professionals,
that high-end tools must work basically the same way.

Everyone knows what an equalizer does, and normally you don't fool
with it.  However, if you are using the hiss remover, then you must at
least consider tweaking the extreme high end with the equalizer.  That
combination will sometimes rescue a hiss-reduction that would otherwise
have been unacceptable.

The vast differences in how individual records (and even individual
tracks!) interact with noise reduction is the main argument for finding
an easy-to-use set of tools and mastering them, rather than getting a
highly sophisticated program and hoping to use just a few settings.

All the effects I talk about in this posting are obvious and gross,
not the nitpicking of a specialist.  Used with care, these tools are
incredible.  It would be a bad mistake to try to make CD transfers
without them.  If you already have a stack of untreated transfers,
you are in great shape, because the worst part (actually playing the
records) is behind you, and all the fun (cleaning the files) is ready
to go.

Jim Neher