What exactly is PRaT???

@panzrwagn "Overall, I believe PRaT is fundamentally about controlling and minimizing stored energy within a system. It is the release of that stored energy that smears the sound, robbing the music of PRaT."

I think you’re right on the mark based on my listening experiences. Two categories of components that seem to inhibit PRaT from my perspective are:

1. High mass turntables
2. High powered Class AB amplifiers

Both store a good amount of energy from what I know: high mass turntables are slow to release vibration and higher power amplifiers need larger power supplies to handle the bigger current demands.

@bolong Agreed with your statement that "It requires a clean start and stop of a transient". I agree that I don't think it has anything to do with timing per se, but rather having sharp leading and trailing edges for when a sound wave starts and stops.

@calvinandhobbes 

I think you’re right on the mark based on my listening experiences. Two categories of components that seem to inhibit PRaT from my perspective are:

1. High mass turntables
2. High powered Class AB amplifiers

I never experienced PRaT until I acquired my Hegel H390 (Class A/B rated at 250 watts @8 ohms). 

@steakster

You’re welcome. Glad someone found it worthwhile. Those guys are two of the best player-teachers online.  

Ah, Chris Rea.  First heard "The Road to Hell" in a clapped-out army truck descending into the Great Rift Valley in Kenya, with truck wrecks littering the landscape.

Later I was MC for a conference and had a copy with me.  Played it as attendees drifted in, the morning after the big dinner.  A colleague rushed up: "the sound system is broken".  All he could hear was raindrops and windscreen wipers.  Then the first crescendo hit.

Chris really cares about the quality of sound, and all his recordings are studio-made.  I heard him live in Melbourne and he was absolutely mortified that he could not get the exact sound he wanted.  He never toured the USA

Herb’s latest and recent reporting on an actively configured vintage horn/tube setup, a rarity (i.e.: active) with this kind of setup, where he goes:

A couple of minutes into the first demo disc, I started bouncing on the couch raving about the boogie-PRaT factor. [...]

Notice the inclusion of the more layman’s term "boogie-factor" as a variation of PRaT, the latter of which seems to have been described around here as a somewhat over-complicated and esoteric attainment to come by through years of audiophile cultivation and final revelation(?). I can only assume that for those it’s a rare (and late) trait to have experienced, not because it’s the Sasquatch of audio qualities but simply due to setup choices that didn’t bring out the boogie-factor (sorry, PRaT) in a prevalent fashion. Oh, I can imagine seeing PRaT entering what has otherwise been a stale audio serving through years being something of revelation when it adds up to the other qualities that has been meticulously harnessed over time, but making it a matter of an "enlightened progression" over decades is just going off the rails in my book.

Maybe to some it’s the other way ’round; they attained PRaT long ago and earlier in their audiophile journey, and only later added the perhaps more conventional audiophile traits of imaging, resolution, airiness, balance of presentation, etc. As is I can definitely attest to the importance of boogie-factor/PRaT as a vital sonic ingredient, on top of many other things.