upgrading... which amp?

First, exactly what do you mean by the Sony becoming "tired" lately? Usually, a receiver either works or it doesn't. Have you checked to make sure the speaker cable connections are snug?

Aside from that, I wouldn't worry about having too many watts of power, as what's important is not having too LITTLE power, which could result in the amps clipping and harming the speakers. If you do want to try a new receiver, you might try something like an Onkyo TX-NR929 and see how you like it. The 929 likely has a more solid amp section than an older ES series model.

What is your budget for a new amp/s? Real heavy weight class A amps will provide punch but is expensive. The Class D amps which are gaining in popularity and use are considerately less money, but may not please you sonically. You have to figure out a way to audition these amps.

Hello,
thanks for the response.
It seems like I have to crank the sony up a lot more than I used to, to maintain the same listening level! Maybe i'm just getting deaf in my old age! LOL.

I found out today what that old amp I tried out before was, and it was a Luxman. I tell you I remember this thing really bringing the 4410's to life. If I was to spend ~$1000 what would be a good 5 channel amp for this price range?

I see someone has a Bryston 5 channel for sale here, maybe this would be a good match?
thanks

The caps in the Sony psu may be leaky.

If you can find a used Sherbourn 5/1500A in good condition to try out, you may like it.

200 wpc x 5 channels, with FIVE toroidal transformers, weighs 80 pounds. It also has a signal sensor which turns it off after a period of inactivity, and also turns it back on when it receives a signal.