bro,thanks for your suggest, my amp is marantz sr 6003 and my center speaker is usher s525,l use sr6003 preout to rda7 ,it looks like l misunderstand what mean"preamp"
haha,so rda7 is a poweramp,is preamp mean rdc 7.1??
my sr6003 has audyssey multi eq,but l lose my microphone that l cant do it...