It's not really necessary to buy this kind of equipment if you don't want to. If you have access to a reasonable cassette tape player, you should only need a suitable connecting lead and some audio editing software to achieve your purpose. A good free audio editor is Audacity
Ideally, use a cassette deck to play the tapes, as this will provide a line level audio out, and a decent quality audio signal to record. If you only have a modest number of tapes to transcribe, but don't own a likely player yourself, a tape deck borrowed from, say, a friend's stereo could be pressed into service. A deck normally has stereo RCA outputs, and most computer sound cards have a 3.5mm line in jack, so a lead with those connectors is required, like this:
Even the basic sound (such as onboard chipsets) on average computers can do justice to cassette recordings. To record to a CD, the recordings you make on the computer need to be stereo 44.1KHz 16bit WAV files, and then you choose to burn them to a music disk. Each CD can hold 74 or 80 minutes according to its stated capacity.
Alternatively you can make the recordings in MP3 format, and burn discs as data discs which can be played in MP3 capable CD/DVD player or computer, or put the MP3 files on a flash drive, MP3 player or whatever. Even using high quality MP3 formats, this fits many times as much material into the same space.
If you only have access to some type of portable cassette player, an adaptor to connect from a headphone output, or as a last resort, the speaker connections, will work, but not quite as well as having a proper line out.
Edited by Platypus, 04 August 2009 - 07:47 AM.