[ale] copying lps to cds

[Jeff Hubbs]

I'm real sorry, but if it were trivial to him, do you really think he would be
asking?  This isn't the kind of reputation I'd like for this listserv to gain
when it comes to giving support.  This fellow ("Wandered Inn") has been on the
list for a good long time and I don't think this is how he or any of us should
be responded to.

Having dispensed with that, let's see if I can give the guy some useful
information.

My experience is limited to CD-R production under Windows 95 using the bundled
software that came with my HP SureStore and Syntrillium Cool Edit 96 for
recording and editing.  Sound card is a Sound Blaster AWE64 Gold.  I'd be more
than happy to use Linux for this purpose once no-cost software similar to Cool
Edit becomes available.  I deal mostly in transferring reel-to-reel tapes to
CD-R and I have also done several acetate 78s.

You will want to produce separate .wav files for each track on the LP.  It is
very important to watch your levels, much more so than when dealing with tape
recording, because the result of an overload - basically a "clip" of the
waveform - sounds bad and is very bad for power amps and speakers on playback.
Cool Edit has really nice filtering and noise reduction features.  For LP
recordings, it would be good to filter out everything from about 15Hz and below
(watch what your woofers do when playing an LP between tracks really loud and
you'll see why - they usually wiggle all over the place).  For setting levels,
you may want to pull some tracks from a commercial audio CD into your audio
editing sw and look at a track to get a feel for where you should aim
level-wise.  I'm not sure where the absolute maximum should be parked in those
16 bits' worth of headroom, but suffice it to say that the peaks ought to go
somewhere between half-max and max.

Regarding clicks and pops:  I imagine there are filters you can develop that
would go a long way to eliminating these but Cool Edit doesn't have anything
specific for that.  I am dealing with a lot of 78s so you can imagine that I
have to deal with that a lot.  I find that although it's a little tedious, you
can sit down and splice them out by hand, and if you are careful about how you
do it, the missing few milliseconds will go unnoticed.  Another technique I use
- which sdly won't be available to you because you're already at 33 1/3 RPM on
the turntable - is to record 78s at 33 1/3 using a sample rate equal to 44,100 *
(33.333 / 78).  When you look at the result in the frequency domain (i.e.,
spectrograph mode), you will see that there isn't any useful program above about
300 Hz; the rest is all noise.  So, I do a lo-pass brick-wall filter at 300Hz
and then change the sample rate back to 44,100 - and the pops will have been
significantly muffled.  This works because slowing the turntable down moves the
program material down in frequency but the pops and clicks stay the same.  When
you do the brick-wall filter, you cut a lot of the sonic energy out of the noise
while not affecting the program.  It isn't perfect, but it's better.

I started working on CD-R burning some two years ago and I have managed to
salvage some unique (i.e., no other copies exist) recordings.

You can "rip" .wav files from individual audio CD tracks and burn a new CD with
the .wav files rearranged or interspersed with .wav files from other sources.

I am not well-versed in the kinds of audio software available for Linux, but
Cool Edit is VERY nice and we should bug them to support Linux.  For the time
being, you may have to bail over to Windows to do this properly.

- Jeff



Jeff Dilcher wrote:

> > > Yes, that is also possible.
> >
> > Wow, thanks that is so much help.
>
> No problem.
>
> Suggestion:  Ask specific questions.
>
> Anyone could write volumes about music recording and computers.
> Everything you asked is pretty trivial, and well documented on the internet.
> Have you searched all the search engines?