Sugden a21se here, 30 watts into 8 ohms, 40 into 4 ohms. Driving my 89 - 90 db tannoys just fine. I am seemingly never at a deficit when it comes to volume. The tannoys however sound great even at lower volume, so I don't find the need to play them to loudly, but when needed or wanted, the sugden is just fine. Class A is different, I'm a believer now that I own one. $3250 for the a21se, best money I've spent thus far aside from going with tannoys.