Here is a Sega Master System 2 "prosound" -- that is, taking the sound directly from the VDP chip, which contains the integrated SN76489 clone. The VDP that is found in the Australian PAL SMS2 is the 315-5246.
Normally, the only way to get sound out of the Sega Master System 2 is via a television set, a VCR or a dedicated RF demodulator. The sound quality of course suffers (as well as the picture quality) and also it is quite an inconvenience, making the console unusable for live use in music concerts and recording etc.
Read the tutorial here.