Yes, it could be a tube but I have also heard a bad resistor sound like this too.
MA2275 Issue need some advice
Looking for some advice. McIntosh MA2275 integrated and the left channel sounds dirty, at higher volumes the bass sounds staticy and broken, almost like a blown speaker. Using B&W 805D's, swapping the speakers the problem is still there but on the other speaker so its coming from the amp and not the speaker. Do the tubes need replacing?