Attention all owners of Amiga 1200 rev 1A! In the audio circuit on the A1200 rev 1A motherboard, the gain of the OP-amps is set very high. In fact, it is set so high that portions of the swing of the audio is reverse biasing the polarized AC coupling caps C324 and C334. Also, the high output coming out from the RCA-jacks at the back of the A1200 rev 1A might drive some amplifiers into distortion. The reason for this is that the feedback resistors R321 and R331 going to the inverting inputs of the OP-amps are of a too high value, which makes the OP-amps have a really high gain resulting in an audio output with a very high amplitude. The value of these resistors is 1.5 kOhms. Commodore recitified this mistake in later revisions of the motherboard. In revision 1D4, we can find 680 Ohms resistors in there instead, which sets the gain of the OP-amps to a more decent level. This is all being demonstrated in this video. Revision 2B and 1D3 are now also confirmed to have the 680 Ohm resistors on the motherboard. If you find another revision other than 1A that has the 1.5 kOhm resistors on the board, please let us know in the comment section. The motherboard in this video is the very same one as the one that had a color problem earlier, which I featured in another video. Feel free to have a look at that repair as well. The video can be found here: https://www.youtube.com/watch?v=8xlG9Ln5o30