Converting cassette tape recordings (or LP records, the process is the same) to CDs or MP3s is neither quick nor easy.
If you are only used to converting CDs to MP3s, that is quick & easy. That just requires you to bung the compact disk into your PC, run up one of the many programs that will do the copying, tell it do the job and wait just a few minutes. By comparison the hassle of converting tapes will come as something of a shock.
Firstly the tape player will not play at 48 times normal speed so you will have to wait as long as when copying tape to tape just to get the recording into the computer. Secondly the output volume of the tape player will need to be manually matched to the input volume of the PC. Thirdly the track breaks will probably have to be put in manually. Fourthly the volume might vary between tracks.
As for why anyone would want to do it, one reason is to avoid the annoyance of having to repurchase ones old legitimately paid for music recordings just because the medium has changed. However, my main reason was that I had a collection of obscure international folk dance music recordings much of which was only available on tape. Other reasons I have had for converting tapes to CDs have included preserving nostalgic family voice recordings and friends' amateur musical performances.
(This article was originally written in 2006 but the process in 2020 is still essentially the same, just different software. E.g. Audacity to copy to WAV, put the track cuts in, cut the file into tracks & encode to WAV/MP3 (there is a comprehensive tutorial for Audacity tape copying) then one of many free programs to burn WAVs to CD and Puddletag (Linux) or Mp3Tag (MS Windows) to refine the MP3 tags. Also note that laptop computers since around 2010 typically only have mono line-in so you might need to buy a USB stereo line-in adapter.)
The basic process is:
Stage 1 is tedious. Stage 2 (& 3 if done) are the most technical. Stages 4 & 5 are easy.
Details & tips follow. The general techniques apply to any operating system but the example software described is deliberately Microsoft Windows based because this article is based on a email I wrote for someone asking me how to do it on Windows and because I have only tried it Windows so far.
Use an audio cable to connect the Line-Out or headphone socket on a tape player to Line-In (pale blue socket) on PC.
You need some recording software. Do no use Windows Sound Recorder. It is rubbish.
I used CD Wave which I bought for 15 Dutch Guilders (shows how old it is!). The current version is available from http://www.milosoftware.com/cdwave/. There are other programs that will do it but that was the best one I found at the time I started converting tapes to CDs. If you want freeware then the music editor Audacity will do it but, as that does so much more as well (it is a comprehensive sound editing program), it might daunt a beginner. A program dedicated to the task, like CD Wave is, is probably more easier and more convenient to use.
Basically the procedure is simple (but time consuming): tell the software to save the incoming sound as a WAV file, where to save it and to start saving then press play on the tape player and wait for it to finish.
A WAV file is uncompressed sound data and much bigger than an MP3 file of the same sound. It is better to work with WAV files than MP3 files until the editing is over as each MP3 decompression & recompression during editing will slightly degrade the sound quality. Get all the editing done first, then compress to MP3. If you are short of hard disk space then a using a lossless compression method such FLAC is an option but it is hardly worth it for this task as hard disks are spacious thesedays and the big WAV files will only be there temporarily.
Just when you thought this stage was easy, albeit time consuming, here is the bad news. Unfortunately there are lots of frustrating catches with getting the volume correct.
Getting the volume as high as possible to reduce the relative effects of noise in recording without distorting or clipping is fiddly and tedious. Firstly in the Windows sound settings turn the volume of Line-In for recording up to maximum (otherwise it will clip even below maximum recording volume as the hardware will be taking the sound in above its maximum and then de-amplifying it!). Then mute all the other sound inputs in the settings (you don't want beeps from email programs or static on the microphone socket being recorded). Then go to where you think the loudest part of the tape is and try recording a few seconds of that. Then check that recording. If your imagination works best auditorally then listen to the recording and if you hear clipping distortion that was not on the original tape recording then reduce the tape player volume and try again. If your imagination works best visually (as mine does) then you can look at the waveform in a audio editing program for clipping which will show as peaks of the waveform flattened at full range amplitude limits; reduce the volume likewise if the clipping is present. On the other hand if the absolute value of the maximum peak is less than about 70% of the full range amplitude then increase the volume and try again.
Eventually you will have got the volume right. If there are any other parts of the music that might be as loud or louder then go to those and repeat the procedure but only reducing the volume if it is too loud not increasing it.
When you are sure that the volume is correct. Make the recording. This can be done unattended so although it takes a long time it does not take much work.
After making the recording check for clipping again throughout (this is much quicker visually, taking usually less than a second, than auditorally, which involves listening to the whole recording). If it clipped, reduce the volume appropriately and rerecord again.
It is even worse if the tape was a compilation with different tracks at different volumes. Either record each track to a separate WAV file individually with the volume adjusted for each or record the whole side of tape multiple times at different volumes as separate WAV files then use the loudest non-clipping WAV file for each individual track after splitting the big WAV files into tracks in stage 2.
After this stage you should have a side of tape converted to a WAV file and can be pleased that the really tedious stage is over.
You will probably want to trim off silences before & after the music (& maybe between tracks). Unless you have recorded a single, you will also probably want to insert track breaks. This involves specifying where to break the recording into sections and which of those to keep (i.e. keep the music not the silences). Ideally it would be automatic but I've found that old tapes often have so much background noise that automatic splitting programs are unreliable (sometimes splitting on quiet bits within tracks or not splitting on noisy gaps between tracks). Hence I do it manually in CD Wave which involves clicking on a time-line of the recording to mark the positions to break, ticking (and optionally naming) the sections to keep in a list below and telling it to export. In a general purpose sound editor like Audacity it is typically done by selective each track as a region and saving it as a file separately which is more time consuming. My visual imagination is better my auditory one so I primarily use the sound envelope/waveform graphical display to tell where the tracks are then confirm by listing but one could equally well do it by sound (clicking on different places until one finds the breaks, homing in on them by recognising where in a tune one is).
The result is one WAV file for each track.
Sometimes I make a few minor alterations in a sound editing program (I currently use Cool Edit 2000 Lite but the current version of Audacity has more features than that version of Cool Edit and is free). The commonest is with the volume as I don't want to have to keep running to the volume control when playing a CD or dance teaching so I want the volumes the same for my tracks. (I also do this to for some music that originally came on CD, creating a volume equalised CD copy of the CD, when the original CD tracks varied too much in volume). To save having to use a bigger amplifier (and so they match commercial CDs in volume), I also want them them recorded at at least 70% (preferably 100%) of the full volume.
This is quite easy to with an amplify command in a sound editing program and some CD recording & MP3 playing programs, such as iTunes, can be told to automatically amplify each track to a uniform maximum level on playback or when recording to CDs but if there is even one fraction of a second glitch or loud symbol causing a spike somewhere in the track then that will be stop the rest of the track being increased in uniformly in volume leaving it quiet.
To cure that, I select the spike (typically < 1/100 s wide so the edit won't be noticed as long as it is smooth) in the sound editing program and reduce its volume to match the rest of the track and repeat likewise for any other spikes in the recording. Then I select the whole track and maximise the volume and, hey presto, the whole track is up to the standard volume.
If this sounds scary then note that it is just an optional stage.
The iTunes program is convenient for this & is freeware (there are lots of free alternatives though). Drag the folder containing the tracks as WAV files from Windows Explorer to the left pane of iTunes. It will be shown as a play list. Put a blank CD-R in the drive and use the burn button in iTunes. Easy.
Use a CD-R (write-once) not a CD-RW (rewritable) unless one is sure that the CD won't be used on a CD player incompatible with CD-RW. Although it is wasteful in CDs if, for example, the CD is only going be used for a short period (e.g. playlist for an event) there is a risk of incompatibility, particularly with older audio CD players. This is because CDs were originally designed to be only produced in large scale in machines that wrote a disk at once by stamping holes in the foil layer and the original audio CD players were made to that spec. CD-Rs are written to by burning holes in the foil which produces a CD similar to the original spec but CD-RWs are written to by changing the colour of temperature sensitive dyes which gives less contrast for the CD player to read. I've hosted an event where the new CD player broke down and the old ghetto blaster I'd brought as back-up failed to play the CD-RW my co-host had brought her main section of music on. CD-R is probably also more stable for archiving than CD-RW due to the recording process not being designed to be reversible.
NB. Recording to CD at this stage rather than from MP3s later on means you get an archive copy on CD with no MP3 compression so the audio quality will be (slightly) better (or, at least, no worse).
If you made a CD then you can convert that to MP3s in your normal way. However you don't need to make a CD as you can convert direct from WAV to MP3. This can also enable the conversion software to copy the file names from the WAVs to the MP3s which saves some typing (provided you bothered to name the WAV files of course).
iTunes can be used for this too. It is not renowned as a particularly good MP3 encoder but it it has an easy user interface, is ubiquitous & is freeware. If you have not already done so, drag the folder containing the tracks as WAV files from Windows Explorer to the left pane of iTunes. It will be shown as a play list.
Go to options in iTunes and set the 'import' method to MP3 with the settings you like. I used 196 kbps with default values, VBR on and 'Joint Stereo' off. The 196 kbps was more than was needed for equivalent quality of very clear recordings but recordings from tape typically have additional noise and that consumes bandwidth in the encoding leaving less for the wanted sounds. The "joint stereo" being turned off, despite considerably increasing bandwidth requirements, was because I was not certain that it was not "intensity joint stereo" which essentially means converting to mono at lower frequencies. If it meant "mid/side joint stereo" then that causes no extra losses (it stores left & right channels as average & difference instead of completely separately) yet reduces bandwidth so that is good to enable (note added 2020: Audacity's "joint stereo" is mid/side joint stereo). Also set the 'iTunes folder' to where you want the MP3s to be saved when created (once created you can drag them to wherever you like). If you already use iTunes for CD to MP3 conversions then you have have already done these steps.
The conversion is easy, just select the tracks in the right hand pane of iTunes that you want to convert to MP3, right-click on them and select 'Convert to MP3' on the resulting menu. Done.
Unfortunately you will probably need to type in the MP3 file names and MP3 ID3v2 data (track names, artists, genres, album names etc.) yourself as the online databases probably won't recognise your converted album even if it is a common one because the automatic album identification is based on precise track lengths and the positions of the manually inserted track breaks are unlikely to exactly match those on the commercially produced CD if there is one.