If the audio of your Amiga 1200 Rev 1B, A600 Rev 2B or maybe other revisions is too loud (not distorted), that is caused by two resistors. Tristan Zondag confirmed the A600 Rev 2B is also affected.
R331 & R321 are 1,5K Ohm, while they should be 680 Ohm.
If I test the output voltage level with the 500Hz test sine from systest the DC offset is +/- 5,6V, it should be +/- 2,4V.
So replace them with two 680 Ohm resistors and the audio level should be good, with a DC offset of 2,4V.
Difference between Rev.1 & Rev.2 board (schematics)
Affected boards: A1200 Rev 1B, A600 Rev 2B