Two terms I don't understand - please explain

Dynamics AND timing. Big difference from Dynamics alone.

Slam = dynamic impact, i.e., how well loud, fast extreme transients are rendered.

Prat (or PRaT) = Pace, Rhythm and Timing -- a component with PRaT gets your toes tapping, let's you hear an feel the drive and pulse of a tune (maybe even puts it there, in some cases, e.g., where a TT spins too fast). Pretty much the same thing as boogie factor.

Roughly, anyway.

Phaser's explanation of slam is better than mine. It refers specifically to bass transients.

Dcstep. I disagree that every TT that's not "grossly" out of whack gets pace right. I don't think belt drives in general do. My Lenco does, though. Also, poor speakers or badly matched speakers and amp can be sluggish.

Well, you keep asserting that. I don't see a host of folkks rushing to agree.

You think the shape of the wave will not effect timing? The wave is IN TIME, no? Not that that proves anything, but the idea that blurred attacks and decays -- and different degrees of blur at at different frequencies -- cannot effect perceived timing pace and rhythm is not at all ridiculous.

If your drivers aren't well controlled by the amp, they will sound blurry at the edges of the note (well, through the whole note) and that will give you a PRaT issue. Woolly bass is fuzzy arounf the edges, and is certainly not PRaTty bass. Just when do you tap that toe?

Belt drives can be wonderful. No denying it. I learned about PRaT from a Naim driven Rega Planar 2. Actually, my Naim Nait 3 was pratty with all sources, in a way previous amps were not, and in which my NAP140/NAC32.5 is, but my Scott 222c and Sherwood AM-7040 are not -- though I don't think that's a flaw in these latter, as I think Naim are (or were) designed with highlighting the prat-making bits of signal. Hey, it works, and is extremely exciting. As I said in my earlier post, PRaT can be introduced into a signal.

Anyway, I was quite happy with various belt drive TT's until I heard a Lenco.

"Please explain how an amp alters either Pace, Rhythm or Time."

Thought I did that, to an extent. Another shot: having microdynamics that do not slur attack and decay.

But I'm no electrical engineer, so won't pretend to play that game.

Anyway, some amps -- Naim in particular -- are famous for having PRaT, and are even (with Linn Sondeks) the source of the whole concept. I think what PRaT refers to is essentially pegged to whatever it is they do that people identified in the sound and called "PRaT. Not sure what it exactly is, or what they do that accounts for it, but whatever it is, it's PRaT", and Naim amps do it. Krells and CJs, in comparison, I gather, don't.

Well, transient response too; but I don't think you can fully distinguish transient response from dynamics. Anyway, nobody ever said PRaT was reducible to any one separable factor. It's more complex than that. So the fact that it clearly has to do with dynamics and isn't clearly exactly one other thing doesn't mean it's just dynamics.

I just very casually scanned the article from Martin Collins, and at least on that scant basis it seems clear to me that he does not vindicate at all Dcstep's claim that PRaT is a misnomer for dynamics, and that all decent gear has it. Quite the contrary. Quite.