For repairing amplifiers.
Left and right channels have identical signals. The files were created using the excellent shareware Goldwave audio editor.

Track listing is as follows:

1) 1000Hz sine wave
2) 1000Hz square wave
3) 1000Hz triangle wave
4) 440Hz sine wave
5) 20Hz sine wave
6) 20KHz sine wave
Each track is only 1 minute long, so use “Repeat” on your CD player to obtain a (nearly) continuous tone.
Don’t play this CD through your speakers, unless the volume is at minimum.
The audio tracks are recorded at 50% dynamic range, to avoid any clipping in the CD player itself (of course it should not do that, but my portable CD player used for testing is not perfect, maybe yours isn’t either).
Download  a ZIP of the .ISO and .CUE file ready for burning with your favourite CD writing software.
Audio test CD