If you're seeing equal spl reduction across all channels, this doesn't sound like it could be the amp. The 5 channels are all separate, with their own power supplies. Are you using the original power cord for the amp?
I noticed there's a recent firmware update for the Yamaha. Stated something about ypao volume function.http://www.hardwarezone.com.sg/tech-news-new-firmware-updates-bring-4k60p-support-several-receivers-yamahas-aventage-a30-series
Hey bud, thank you! I was under the same assumption that it wasn't the amp as it was an equal reduction of SPL across the board. My current model (CX-A5000) doesn't have any recent firmware updates available. I'm at a loss as to why I'm having to raise my volume much higher than usual to have decently audible sound. If it was happening on only 1 or 2 channels I'd try changing interconnects but on all 5 channels is what has me stumped. I realize the digital volume indicator on my Yamaha is not much help to anyone but if it matters I'm pushing it to around -18db in the past I'd have decent volume at around -27db -30db..
If any one may know of anything else I may try, I would greatly appreciate it. It's driving me nuts LOL!!!
Thanks very much guys!!!!