Hi-Looking for one of these-audio from TV to speaker set-appreciate any help on where to find a good quality one around Sukhumvit?

Thanks in advance.

You can purchase these practically everywhere. From 7/11 and the Mom 'n Pop store that sells sat/stereo electronics or mobile phones.

Quality... that might be more difficult to discern. As far as sound goes, there all good.

Mean-Time-Between-Failure is where most will let you down. Be prepared to replace it.