Sapphire Tech-USA has replied and confirmed : " ... No there is no audio chip build on to AGP cards ... ".
" ... card does not include the Realtek HD audio on-board processor - no HD audio output is available. This is due to the AGP bus - there is no way to expose this additional hardware to the system as a device, so it was omitted ... " ... rage3d.com
so it is definitely confirmed by
esteemed reviewers and
most importantly, Sapphire Tech .. that Sapphire Radeon HD AGP cards DO NOT have audio chips; hence no HD audio.
p.s. honorable mentions to the sapphire forum monitors at vgaforum . com
for guiding me in proper posting etiqutte. ... priceless.