Dave,
That’s what occurred with the first example (A-S1100) I had in my system, however, it sounded and functioned just fine. I only returned it to try another amp. Ultimately, the Yamaha sound beckoned and I bought another. This one runs warm above the capacitor bank, but only after a good hour or more.
Maybe the 3000 is biased into class A some, even though it’s not advertised as such. That wouldn’t surprise me either and might account for the heat.