If you have very revealing speakers and a quality ss power amp, letting it warm for at least an hour definately makes an audible difference. I can understand Kkm's thoughts that this may be a design flaw but have come up with my own theories on this. For example the Odyssey Stratos has a power switch on the rear obviously because the amp should be left on at all times to sound its best. I feel that the overkill on the Stratos's heatsinking delays the output devices from reaching a desirable operating temperature that would in turn keep them from sounding their best at least for awhile. So I would not view this as a design flaw but rather a careful design that allows the Stratos to operate at cooler temeratures even after warmup thus giving the amp longevity.
In Contrast the McCormack amp does not nearly have as much heatsinking as the Odyssey and it takes a shorter period of time to reach its optimum operating temperature for best sound but it does run much warmer than the Stratos even though both amps are biased up a bit.
There are some cases I have found that some amps actually do sound brighter if left on continously but some would say that the amp is not brighter but just more revealing & transparent. On the other hand there are some amps that just start sounding warmer when left on all the time. I suppose that is why we have an amp game.
In Contrast the McCormack amp does not nearly have as much heatsinking as the Odyssey and it takes a shorter period of time to reach its optimum operating temperature for best sound but it does run much warmer than the Stratos even though both amps are biased up a bit.
There are some cases I have found that some amps actually do sound brighter if left on continously but some would say that the amp is not brighter but just more revealing & transparent. On the other hand there are some amps that just start sounding warmer when left on all the time. I suppose that is why we have an amp game.