Originally Posted by alrose312
It turns out I was searching for volume, when I really should have been listening for the impact that the amp has on the phones. Ray also emailed me and confirmed that most of the gain comes after 1:00. I think I'll continue to appreciate the sr-71a as I continue to listen to them.
One aspect of performance of amp we don't usually talk about is that of power design, management and implementation. It is not just wattage or impedance. That factor alone can determine whether an amp is a good match with a certain phone (system synergy). For instance, a class A, class B or Class AB design can impact how power is delivered to a phone. For class A, full or maximum power is available the moment power is turned on even if the volume switch is at 0 whereas for Class B design, volume is at minimal and increases as the demand for volume is increased. And for Class AB, variable volume is available up to a certain point then full power is available for the rest of the volume range and thus Class AB. So for any particular amp driving a particular phone if good power is not available at low end and is only available at a range beyond a person listening level, then that person may never be able to listen to the phone's optimal performance. I guess that is why the Stepdance performs good at the expense of battery life because it makes abundance of good power at the widest power range. According to Ray, I guess if most of the gain comes after 1:00, then for any phone that can give a listening level performance after 1:00 will perform it best. That is why demanding phones like the HD6x0 sound good with the Sr71a and that is why Ray used the hd600 as the reference phone to develop the SR71a.