Thanks again for the responses and sorry for the delay: I contacted Naim and they recommended contacting Technetron in New York City. Took a little while to get the parts, but the repair was super--full cleaning, new caps and pots, replaced the volume control. I'm happy to have the amp back.
One question: they asked if I ever powered the amp down, I told them no (except for two major power outages it's been powered on for the 15 or so years I've owned it). They said that I should power it off when not using it since it runs pretty hot and constant high heat will damage the internal components over time.
Is this recommended advice for solid state amps?
Thanks again.