See thread on digital amps in the Two Channel
item - Is this what you are asking ?
...
Integrating digital to analog convertion (DAC) with a power amp may make economic sense but, OTOH, think of the cost/performance of a top notch CD palyer ( $2,000 ++) and a top notch amp ($3,000 +) versus proformance / cost of an intergrated unit ($?? !) .
IMHO, integration is not necessarily a significant step forward per se but class D output power amps for producing compact units should make the electronic speaker cross-over & EQ concept more attractive and cost effective obviating current passive speaker XO limitations. Where the DAC is located, as long as it is good quality like SACD, is less important and with separate units at least you've a choice what source & amp to have. Also many still use analog sources like vinyl so an analog amp input will be on demand for a long time to come.
In summary I think the G.O.F. analog amp will be around for a very long time still.
George