OK!
i put here what i did to fix Audio:
go Synaptic-->search-->mark to install-->task-remove-pulseaudio-->apply, on popup window -->apply. Exit synaptic. Reboot.
go Synaptic-->search-->mark to install (related Alsa present in list)-->a2jmidid-->alsaconf-->alsa mixergui-->alsa-plugins-doc-->alsa-plugins-pulse-config-->alsa-utils-->aoss-->apply, on popup window -->apply. Exit synaptic. Reboot
go Synaptic-->search-->mark to install-->pulseaudio -->pulseaudio-client-config-->pulseaudio-esound-compat-->apply, on popup window -->apply. Exit synaptic. Reboot
go root pcc-->Hardware-->audio/sound configuration-->enable pulseaudio-->use Glich free mod (is checked by default)-->Accept-->exit pcc-->Exit synaptic. Reboot.
go to firefox-->
www.youtube.com-->music-->click any song. (plays images but no sound)
exit firefox.
go root pcc-->Hardware-->audio/sound configuration-->disable pulseaudio-->Accept-->exit pcc-->Reboot.
go to firefox-->
www.youtube.com-->music-->any song. (plays images and sound)

Hope it helps others
Greetings