Sorry,i leave this forum for a very long time.Well,after the last seminar,i still have to do this project.I'm realize that voice recognition system, do not need the DAC part.But,i need to implement this part in voice recognition system.Due to this matter,i need to convert the digital signal form into the analog signal form back.It seems likely the voice recorder and feedback function.Can anyone help me to design this part of circuit and how do i implement or attached with this system?..i'm also been adviced to do not use any of ic chip in my DAC design.Sorry,for the poor and broken language.TQ.