One or two dedicated AC wire ?

I hope somebody experienced in this area chimes in, but I don’t think a tandem circuit breaker should be used in this situation.... the 2 dedicated lines would be on separate legs.

IME, audio AC lines should be on the same phase and the current draw of devices in the home  should be evenly distributed across both legs on the panel.
Unless I’m wrong, you would need to put each dedicated line on their own breaker with ground tied from the ground buss to each receptacle (not self grounded).

lowrider57  Thank you. I will search for installing another small electrical panel near the main boxe, for the two AC audio dedicated wire

mental.  I have already a dedicated AC wire for the stereo only... no Tv or Video in this system.  So I was thinking in a second dedicated  only for the power amp. But it's seems not to be so easy

Luckily my electrician owned a nice audio system and made great suggestions. Instead of adding to my small circuit box with old wiring and questionable grounding, he installed a subpanel for two dedicated lines (upgradeable).
A 60A tandem breaker was used in the main panel to supply the subpanel.