In class A amplifier there is no AB operation at full power. If so it would be a class AB amplifier.
A 1 or 2 degree C temperature difference on the heatsink is negligible. The bias is likely set with a control in the unit , to get a certain amount of current through the output devices *not a certain temperature*! Normal variance in the devices are likely responsible for the very slight temperature difference. Nothing to be concerned about as long as the amp sounds OK.
A 1 or 2 degree C temperature difference on the heatsink is negligible. The bias is likely set with a control in the unit , to get a certain amount of current through the output devices *not a certain temperature*! Normal variance in the devices are likely responsible for the very slight temperature difference. Nothing to be concerned about as long as the amp sounds OK.