What is FAST?

Get a copy of the rodrigo y gabriela self-titled CD/DVD and if those extremely fast guitar licks sound crisp and clear your system is "fast". If it sounds somewhat blurred, vague, or muddled, your system is "slow".

But one word of caution... on some systems (especially if you're using a tube preamp and the phase is inverted) it will sound slow, vague and warm... until you reverse the speaker polarity and then it might sound fast and focused if your gear is up to it...

I hope you're thoroughly confused now. Happy New Year!!!

Itball,

Plato and John are quite right to my mind. Sometimes there are music bits in a given composition,which seem to come out of nothing and dissapear again just as quickly as they have come at high speed. You might compare this with a sudden snap of a whip, a sort of cutting sound often, which comes and goes in a split second. This happening is called a "transient" and this happens when the sound arises out of nothing and then decays into nothing. A system is "fast", when this sort of thing reminds one of the real thing, just as Plato has pointed out.
Mind you though, a system which is nothing but "fast", would be unnatural to our ears. Because in music you might need a fast transient as the note appears and a slow decay of the note, as it disappears and then again, just the other way around might sound right. So you see, it is a complex thing. A good system should be able to do both and to do justice to all the shadings between slow and fast at the same time, without sounding harsh, distorted or unnatural and it should be able to do this with loud pieces of music just as much as with soft pieces. Calling a component "fast" is often enough sales talk, even though perhaps justified, because the fastest component will be slowed down by the slowest component in a system. Therefore in my opinion it is better to judge an entire chain from source to speaker to find out if it sounds right or not as far as the question of "speed" is concerned.
Cheers,
Detlof

Why would "fast" be synonymous with "transparent"?

Fast should mean quick transient response, but nothing can be taken out of context: you can't, as audiophiles do, find a fave word and run with it. Fast could mean an amp with a high slew rate, then someone will point out that some amps with a low slew rate sound terrific. Do you judge the beauty of a women based solely on, let's say, the nose? A system is a chain of many components and each component is the result of many choices or compromises. To say that fast means transparent gives pretty short shrift to distortion and noise.

"Fast" is only part of the sonic story, but an important part I think. It might be easy to confuse the term "Fast" with "Bright" and "Slow" with Dull". I think the later comparison is stronger than the former. I agree with the previous posts that my definition of "Fast" is the ability of a system to accurately reproduce the leading edge transients in music. My view is that getting leading edge transients "right" is a joint effort from source to loudspeaker, but seems to have its greatest test within the amplifier.

My limited experience is that solid state and some digital amps can be very good at leading edge transients, but can have a harder time handling harmonics and trailing edge decay. Cheaper digital amps and sources can sound "Fast" and exciting at first listen, but reveal artifacts or sins of omission in the overall reproduction that on closer listening turn out to provide an overly "Bright" sound, lacking body, natural smoothness, sustain and decay.

Conversely, tube gear, especially older versions, can be syrup "Smooth" and "Sweet" but doesn't always get the attack altogether right. Nowadays, the more you spend on tube or transistor gear, generally the less these artifacts impede on the sound in either direction.

So "Fast" is and important aspect of reproduced sound, but not by a long ways the only important aspect.