Recording LPs on my Computer.

[I get asked this question quite frequently, and i have a document prepared to respond, so i thought i'd post it here. Another post will cover my history, ideas, feelings and impressions about digital music.  This is just the techincial details of how to do it.]

connecting the computer

The key was setting up the computer so that it is just another component in my stereo system.

When i look at the audio selection on my stereo i have the following buttons:

    PHONO          CD              FM                AM           TAPE1              TAPE2-VIDEO/TAPE MONITOR

Each of those buttons controls a channel, that is, an audio feed.  There are plugs on the back of the amplifier each for channel.   PHONO and CD are input only channels, they receive audio from another source. The FM and AM radio channels are built into the amplifier so there are no plugs. 

TAPE1 and TAPE2 are also input channels, but there are two sets of plugs for two cables.  In addition to the input they have output plugs so that you can direct that audio elsewhere, usually to make a recording. 

I wired up the stereo like normal: the turntable is plugged into the PHONO input channel on the amplifier.  So when i choose PHONO, the sound from the LP playing on the turntable comes out of the speakers.  I wired up my reel to reel tape deck on the CD button.  I thought that was funny. 

My cassette deck is wired up on TAPE2.  The in channel works like all of the others.  The out channel on the amplifier always feeds from the cassette deck so if i start the tape recording, it will record what ever the stereo is currently playing.  That's how all tape decks are wired up.

Here's the interesting part.  On the channel for TAPE1 i connected the sound card on my computer.  It is also an in and out channel like the cassette deck so there are two cables.  The in channel works like all of the others.  The out channel on the amplifier comes from the computer so it will always feed what ever the stereo is currently playing.  (I built my own cables, but you can now buy cables at Radio Shack with a 3.5mm stereo jack that plugs into a sound card on one end, and a pair of RCA jacks for the stereo on the other end.) 

My computer is a tower unit that sits under my desk just below the stereo. It stays permanently connected.  There is no reason why you can't use this same set up with a laptop that is sometimes set on top of the stereo and plugged in just for that purpose.

So just like when i punch the FM button i hear the radio and when i choose the PHONO button i can hear the turntable, when i choose TAPE1, i can hear anything the computer is playing.  This is nice, because i can play music on the computer and it plays over my stereo, on either the speakers on my desk or the speakers in my living room.  I can also listen to books on tape, streaming audio or video from the internet directly on my stereo.

Here's the important part: because i set up the computer exactly as a tape deck on TAPE1, there is also a recording feed that goes out of the stereo and into the computer.  Whatever i play on the stereo feeds into the computer, just like with the tape deck. I have to tell a program to listen to it;  most of the time the computer ignores this incoming analog audio feed and nothing happens.

computer settings

The operating system manages where the sound comes from, (My computer runs Windows 7 so detailed explanations are based on that, but all operating systems can do this in a similar way.)  In Windows control panel selection SOUND, there is a pulldown menu to select which audio feed the computer is actively using: the MICROPHONE, the INTERNAL stereo mix (eg. internet streaming or a music program or even a CD) or LINE IN (which is the audio feed from the stereo).  When a feed is chosen, any application in the computer that has the ability to work with audio will receive audio from that feed, including recording.  I keep it set to LINE IN all the time.

If you don't one of these items in pull down right click  show and check show disabled devices, and also disconnected devices.   You can then enable the selection you want.  (LINE IN or STEREO MIX.)   You may have to get deeper into the settings for your sound card driver to initialize it. 

recording an LP

I have several pieces of software that are designed to record audio, i quite like AUDIOGRABBER, and i used it for many years, but the one i've been using lately is called AUDACITY.  It was written by a hobbyist in Germany and he gives it away free.   There are many others, some very advanced. 

This software takes the analog audio wave from the sound card and digitizes it, recording it into a computer file.  Rather than the analog wave of an LP or cassette tape, it stores it digitally, like a CD. (It breaks up the solid wave into 44,100 little bursts per second and stores a blueprint of the bursts so a facsimile of the wave can be recreated later by a digital music player.)

AUDACITY works exactly like the cassette deck works, only instead of encoding magnetically on the tape it stores the data digitally on the hard drive.  It even has a button panel designed to look like a tape deck, with play, stop, pause, record, rewind and fast forward buttons.    What's cool is that it also shows a visual representation of the wave and you can manipulate that wave using both what you hear, and the visual representation.   This makes editing fun and easy.  No more razor blades and scotch tape!

With that set up in place, recording is so easy i barely notice.  Any time i play an LP, for example, if i have people over, record it.   I just put on an LP, hit the PHONO button on the stereo, open AUDACITY and click the record button on the screen.  Usually i can do get the software going fast enough that it gets the start of the music.  (Sometimes i have to restart the needle on the record once AUDACITY is started.). Then i can work on what ever i like on the computer while the LP plays.  Often, if i'm writing, i keep the sound off while it records.  My old computer was too slow and i couldn't run any other programs while recording, but  my new (2013) computer can record and do everything else at the same time.

When the first side finishes, i flip the record. The turntable is at my right elbow when i'm sitting at my desk; i don't even pause the recording.  Double and triple albums i just keep the recording going while i change records. When the turntable stops, i mouse click the stop button in AUDACITY.

My current turntable is of mediocre quality.  It is important to have a good quality turntable, needle and cartridge and have it set up right (eg at the right speed).

splitting and cleaning up the recording

AUDACITY lets you edit the audio wave in all kinds of ways (which you can both hear, and see).  If i wanted to i could actually cut a verse from one song and insert it seamlessly into another.  I don't do that!   I cut out the sound of me turning over the record and the bits before and after the record started and finished.

Then, with one keystroke, i run a little software routine in AUDACITY which takes out the turntable's electrical hum, and then another which takes out most of the scratchy needle sound (which we only really hear between songs but is always there).   Even a moderate record can be cleaned up to sound immaculate - better than a CD!

Then i look at the visual wave and see if there are any pops and skips.  Most good condition LPs don't need this at all.  Sometimes i see one or two.  Some of these i can smooth out with another routine, but some i have to manually edit.  Since a pop on a record is usually only about 0.0003 seconds long, if you have steady fingers you can chop out the pop without losing any noticeable part of the music.  Of course you are taking out a little piece, and a bigger piece than that between the samples of digital storage, but still, usually it's not noticeable.  The smoothing done by the

automatic routines usually can't be heard, but sometimes if the damage to the record was severe the repair can make the music sound kind of computery.  My records are in good shape and there are rarely any, but some people have given me some pretty bad records which have come out sounding ok.  It only takes a minute or two to take out a couple of pops, but if the LP is in bad shape it might take a while.

Then i do a Google search for the album, find a list of track names and timings.  Wikipedia is the best resource, but there are other websites that strive to list the songs on every album ever made.  I use allmusic.com and discogs.com frequently.   There is also something called Free Database (Freedb) which will do the lookup automatically for you, but i've had trouble making it work.

When i find the correct album, i cut and paste the names and times into a little program i wrote which formats it and imports it into AUDACITY.  This takes about 30 seconds and prevents me from having to type the track names. AUDACITY uses this import to name each track and it also offers to chop the file in to separate songs at the boundaries indicated by the track timings i imported.  

These times are almost always slightly off.  I have found that the track times listed on album jackets, labels and on the websites are always a little bit off.  If they were always too long, or always too short, i would think that my turntable was not running at the right speed (AUDACITY can slow down or speed up a file, if necessary).  But the errors in lengths vary within the same LP, some too short, some too long.  It's strange.

So using the editing feature of AUDACITY, i look at each cut and move it to the appropriate place.  Usually this is easy and quick, but on some records where the songs blend into each other (or if i'm not familiar with the music) it can take some skill and time.  Once i am happy that the the boundaries are correct, i hit a key which converts the digital wave in AUDACITY into individual audio files (one for each song). 

storing the recorded file

There are lots of possible data formats the recording can be saved in.  MP3 is the standard, but not the only choice and certainly not the best quality. But even with MP3s there are lots of different levels of sound quality (based on how much data is squeezed into each of  the 45,000 samples per second).  Most MP3s are saved at a very poor level (96 or 128 kbs) which sounds awful, worse than a CD.  With the new computer and the new version of AUDACITY i can save not only at a much higher rate (about 300 kps) but it has a feature called VBR (variable bit rate) which figures out when there is not enough sound to need that much space and lowers the quality for that brief instant. Very nice!  Highest quality, keeping the file size down. It's very efficient with space but the quality, while not as good as an LP, is excellent for digital music.

So i save everything as an MP3 at the second highest VBR level, which varies between 96 & 320 kilobits per second. 

I put the individual files in a folder, name the folder with the name of the album.  Then i run a application ID-Tag IT which takes the song name data from the filename and saves it in a 'tag' inside the MP3 file.  That's what displays on your computer or MP3 player when you are listening to it. That's usually one click, but if something is a bit strange i might have to do some editing.   It also standardizes the filenames so all of the music filenames on my computer are in the same style, so they are easy to find and easy to sort.

Next i run an application called MP3Gain which 'normalizes' the volume levels for each song, so you don't have one song that's really loud and the next too quiet to hear.

Finally i place the album folder into a directory hierarchy on the computer, in my 'main collection' folder under the artist's name.  And drop and drag the album into into my random playlist. 

The LP goes back in it's sleeve and on the DONE shelf.

All of this post-processing takes about 5 to 7 minutes (during one song on the next LP) on an LP which is in really good shape.  On an old record which is really hard to find on the internet and/or is heavily damaged, it might take as much as 20 minutes (one side on the next LP).  Lately i've been managing about 50 LPs a week, while still getting work done.