I've been reading about external amp adds to systems for some time now and finally had to see what I'd get if I did so. I have a Yamaha RX-V1 and it has been flawless and really handles everything well but I still just had to check out what I'd possibly get with an amp. Well... bought an Acurus A250 from another member here and plugged in in to drive the mains. DAMN, I couldn't believe my ears. My mains are some old L100 JBL and they just sound phenominal. Much more presence in the mids and striking high end. I run them on small so all that wattage is going where it needs to be. The biggest improvement is that the speakers remaining on the Yam internal amps seem much more dynamic. Music in 2 channel mode is much more powerful. I can see tht my next step will be to a pre-pro setup.