Although Mikelavigne nicely describes some interesting and keen insights toward the terms 'fast' and 'musical', I respectfully disagree with a few of his statements. Particularly:
"what is 'fast'? my perception is that some amps achieve speed thru skipping over texture and nuance." and
"real speed is also the ability to be fast in the bass while getting tonality, texture and linearity thru the mid-bass. this is really an amp/speaker interface issue and not just an amp issue."
I would not think that an amp could be so fast that it skips over texture and nuance." Correct me if I am wrong, but I would think that 'fast' and 'skipping nuance' is somewhat of an oxymoron. I always thought that the 'slower' the amp, the less likelihood an amp can pick up the nuances. I suppose it would be easy to conclude that an amp's excellent transient speed could be perceived to be overemphasized at the expense of an amp's more lacking characteristic i.e. texture or tonality. But I would think it erroneous to assume that just because an amp has 'fast' transistors, that is also why it lacks texture. These characteristics are not an either/or (Hopefully it's both/and.) If a characteristic is lacking in a given amp, then it is entirely possible and probable that one of the amp's stronger characteristics simply sound overemphasized and one or more of it's weaker characteristics sound diminished. Thereby giving the appearance that one or more of an amp's (or any other component) other characteristic(s) had to be compromised in order to implement the stronger one. When in fact the amp simply is not properly weighted to balance it's numerous and somewhat equally important characteristics.
With regards to fast amps, perhaps Peter Moncrief of IAR said it best during his reviewing a fast amp. To paraphrase Moncrief's description of a fast amp:
"(This fast amp) effortlessly reveals layers of musical nuance, is more extended, with the rise and fall time on music's transient details such that each fast nuance is executed more individually, with better intertransient silence, yet at the same time each fast nuance sounds more delicate because it does not sluggishly linger at the peak or get clogged up there, as most amps do to varying degrees.
Some amps try for musicality and delicacy by softening and defocusing the music, smudging and veiling everything. (This fast amp) doesn't need any such trickery as it can go for full articulation and sharp focus, yet still sound accurately musical and delicate, because it is so capably fast and transparent... and is so capable that it handles the entire spectrum, and all of music's demanding complexities, with the remarkable sense of relaxed ease that is the hallmark of a truly great audio component."
Moncrief then relates this to Fred Astaire's dancing which Fred did so effortlessly. Other dancers might come close to Fred but they sweated like pigs trying to do so. Thus the other dancer's straining and sweating were a distraction for the audience toward their performance. Whereas, with Fred, the audience saw only the performance. Not the performer.
I also believe a fast amp generically will work it's speed across the freq. spectrum unless of course there are other and perhaps unrelated shortcomings in the amplifier (of which there usually are). I'm thinking here of the Moon W-5 which is somewhat fast but has difficulties in the bass regions (some say because of it's zero feedback design and/or it's use of J-FETS). In other words, 'fast' is not a cure-all, nor would I think it is meant to be. 'Fast' is simply another characteristic like texture or tonality that should be on the mandatory list for every amp but is lacking in some to many.
Perhaps that is why Dismalonyx opened this thread realizing it is difficult to find such a 'fast' amp.
I respectfully also disagree that a fast amp has anything directly to do with speakers, amp/speakers, or the specific synergy thereof. An amplifier's characteristics stand alone in and of itself. An amp is either fast, or it is not. Whether or not a speaker is able to reproduce transients with the same articulation and speed as the amplifier has nothing directly to do with an amplifier's identifiable characteristics.
Again, correct me if I am wrong, but I simply do not see any direct correlation between the two. Nor would I think there should be. At least not any more or less than the typical synergizing between or amongst any given component to any other component in the system. Of course, with obvious exceptions to one or more given component's deficiencies as I stated above.
And yes, it is indeed nice when an amp combines excellent transient speed along with excellent texture and tonality. I could be wrong, but I simply cannot see how slower transistors are going to make up for an already lack of texture and/or tonality.
-IMO
"what is 'fast'? my perception is that some amps achieve speed thru skipping over texture and nuance." and
"real speed is also the ability to be fast in the bass while getting tonality, texture and linearity thru the mid-bass. this is really an amp/speaker interface issue and not just an amp issue."
I would not think that an amp could be so fast that it skips over texture and nuance." Correct me if I am wrong, but I would think that 'fast' and 'skipping nuance' is somewhat of an oxymoron. I always thought that the 'slower' the amp, the less likelihood an amp can pick up the nuances. I suppose it would be easy to conclude that an amp's excellent transient speed could be perceived to be overemphasized at the expense of an amp's more lacking characteristic i.e. texture or tonality. But I would think it erroneous to assume that just because an amp has 'fast' transistors, that is also why it lacks texture. These characteristics are not an either/or (Hopefully it's both/and.) If a characteristic is lacking in a given amp, then it is entirely possible and probable that one of the amp's stronger characteristics simply sound overemphasized and one or more of it's weaker characteristics sound diminished. Thereby giving the appearance that one or more of an amp's (or any other component) other characteristic(s) had to be compromised in order to implement the stronger one. When in fact the amp simply is not properly weighted to balance it's numerous and somewhat equally important characteristics.
With regards to fast amps, perhaps Peter Moncrief of IAR said it best during his reviewing a fast amp. To paraphrase Moncrief's description of a fast amp:
"(This fast amp) effortlessly reveals layers of musical nuance, is more extended, with the rise and fall time on music's transient details such that each fast nuance is executed more individually, with better intertransient silence, yet at the same time each fast nuance sounds more delicate because it does not sluggishly linger at the peak or get clogged up there, as most amps do to varying degrees.
Some amps try for musicality and delicacy by softening and defocusing the music, smudging and veiling everything. (This fast amp) doesn't need any such trickery as it can go for full articulation and sharp focus, yet still sound accurately musical and delicate, because it is so capably fast and transparent... and is so capable that it handles the entire spectrum, and all of music's demanding complexities, with the remarkable sense of relaxed ease that is the hallmark of a truly great audio component."
Moncrief then relates this to Fred Astaire's dancing which Fred did so effortlessly. Other dancers might come close to Fred but they sweated like pigs trying to do so. Thus the other dancer's straining and sweating were a distraction for the audience toward their performance. Whereas, with Fred, the audience saw only the performance. Not the performer.
I also believe a fast amp generically will work it's speed across the freq. spectrum unless of course there are other and perhaps unrelated shortcomings in the amplifier (of which there usually are). I'm thinking here of the Moon W-5 which is somewhat fast but has difficulties in the bass regions (some say because of it's zero feedback design and/or it's use of J-FETS). In other words, 'fast' is not a cure-all, nor would I think it is meant to be. 'Fast' is simply another characteristic like texture or tonality that should be on the mandatory list for every amp but is lacking in some to many.
Perhaps that is why Dismalonyx opened this thread realizing it is difficult to find such a 'fast' amp.
I respectfully also disagree that a fast amp has anything directly to do with speakers, amp/speakers, or the specific synergy thereof. An amplifier's characteristics stand alone in and of itself. An amp is either fast, or it is not. Whether or not a speaker is able to reproduce transients with the same articulation and speed as the amplifier has nothing directly to do with an amplifier's identifiable characteristics.
Again, correct me if I am wrong, but I simply do not see any direct correlation between the two. Nor would I think there should be. At least not any more or less than the typical synergizing between or amongst any given component to any other component in the system. Of course, with obvious exceptions to one or more given component's deficiencies as I stated above.
And yes, it is indeed nice when an amp combines excellent transient speed along with excellent texture and tonality. I could be wrong, but I simply cannot see how slower transistors are going to make up for an already lack of texture and/or tonality.
-IMO