Converting analog audio to mp3 files under MacOS 10.2.8 - 10.4.8

This procedure worked on an iMac G4 MacOS 10.2.8 and an iBook G4 MacOS 10.4.8 in spring 2007, actual version numbers might differ, check for latest version. I used it for archiving old bird song files.


  • I bought an analog to USB converter (e.g. ADS Tech instant music for about 60 Euros). This hardware is delivered with Nero for Windows but without anything for Mac OS or Linux. Fortunately, under MacOS X you do not need any driver. One could use Garageband but I found another software more convenient to use: Audacity
  • You need a cable to connect your cassette player with the ADS Tech analog converter.

Setting up Audacity:

  • Download Audacity (
  • Download Lame (a library that allows for generation of mp3 from Audacity) ( and save it in the Audacity folder.
  • Plug ADS Tech analog converter into a free USB port (keyboard port works)
  • Select in Audacity > Audacity menu >Preferences... > Audio I/O Recording: USB Audio CODEC
  • File > New project

Import sound:

  • connect cassette player to ADS Tech
  • play cassette, click on red record button
  • adjust sound volume so that entire spectrum is used
  • stop and rewind cassette
  • Close project in Audacity, create new project
  • Import sound (as above - play cassette, click on red record button)

Reduce noise:

  • select a region with background sound (e.g. beginning or end of cassette)
  • Menu Effect > Noise Removal...
  • Click on [Get noise profile]
  • select all
  • Menu Effect > Noise Removal...
  • Click on [Remove noise] (default values worked well for me)

Export to mp3:

Do not use the Detect Silence option!
  • Place the cursor at the beginning of a sound track
  • Menu Project > Add label at selection (apple B)
  • Give name to label (I never managed to move the label, if you want to correct label position, use Undo and repeat procedure)
  • Give such labels to each sound segment you wish to export
  • Menu File > Export Multiple...
  • Export as MP3, use option "Split files based on labels" and "Name files using Label name"
  • Be patient...

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