Amp "timing" ?

Here's what I hear and I don't necessarily attribute it to the amp (though more about that in a minute): when my system sounds 'right' with a good recording, particularly of something like piano music, I hear the attack (with the fundamental) and the harmonics, which decay. There is an aspect of 'timing' to this that gives shape and body to the presentation of the instrument. That is different than what I understand to be "PRAT" and I'm not sure what to attribute it to beyond the recording. I do know that the amps I use on my main system-- the Lamm ML2 SET-- seem to contribute to this because I hear this aspect more through them than some other amps that have been in the system. I'm not staking out any absolute position on this, other than to observe what I hear as an end result. It could also be part of the rest of the chain-- starting with the phono cartridge- where I've heard more emphasis on leading edge with some cartridges (e.g. Lyra) than others ( Airtight).