What represents a major, dramatic improvement is a relative thing that changes over time with your tastes and listening experience. As you listen to more and more gear you get a better sense of which components have an effect on what aspect of sound, and once you have that ability changes that would be relatively minor to a novice become dramatic to the more seasoned listener.
A novice, for example, can readily pick out differences in speakers but can not always hear "significant" changes between CD players, although to a more experienced listener the two CD players can sound like "night and day." That said, I don't think any component makes a more absolute difference to a system than speakers as they are not only responsible for delivering information accurately but, more than any other component, will impart a certain character to the sound given its overall design(i.e. 2/3/4 way, sealed/ported, monitor/floorstander, cone/ribbon/stat, crossover order, etc.) and how it interacts with your room. This is not to say upstream components don't have character as they most certainly do, but they will not impart their character to the extent that speakers do to the overall system(which is why novices don't have a hard time hearing differences between speakers but don't always pick up as easily on changes to electronics). So don't expect the change to be "quantitatively" as different as changing speakers, but "qualitatively" a CD player may yield a bigger improvement depending on your system and tastes.
I'm saying all this because if you don't like the "character" of the sound of your system the biggest absolute(note, not qualitative but rather quantitative) change you can make is with regard to speakers. If, however, you basically like the sound of your system but want to improve it then I subscribe to "the chain is only as strong as the weakest link" theory, and it's up to you to discover which that is through trial, error, and playing a hunch.
I think you're on the right track looking at the source(assuming you're happy with the "character" of your system), and given your level of equipment I'd think you would hear a fairly dramatic improvement to your system by upgrading to a better source component, but don't expect the change to necessarily hit you over the head immediately--it may or may not. Some things to listen for would be not necessarily the level of detail but rather the way in which detail is presented--is it more natural/believable? Also there should be more clarity of space between players/instruments that allows them to more clearly exist individually. Bass may become tighter and better defined. Soundstage may expand in all directions, and elements at the rear of the stage especially may become more readily identifiable and easy to hear/place in space, and echos and reverb will tend to tail off in a more natural and extended way. Anyway, these are some things to listen for, and I bring them up because sometimes you need to listen into the music more to pick up these changes.
So this has a lot to do with perspective and expectations, and the above is meant to help provide some of the former while also managing some of the latter--hope it helps and best of luck.
By the way, my guess is Sean's referring to an EVS Millennium DAC as I had a VERY similar experience when I got mine. Talk about dramatic improvements. Come on Sean--fess up.
Tim
A novice, for example, can readily pick out differences in speakers but can not always hear "significant" changes between CD players, although to a more experienced listener the two CD players can sound like "night and day." That said, I don't think any component makes a more absolute difference to a system than speakers as they are not only responsible for delivering information accurately but, more than any other component, will impart a certain character to the sound given its overall design(i.e. 2/3/4 way, sealed/ported, monitor/floorstander, cone/ribbon/stat, crossover order, etc.) and how it interacts with your room. This is not to say upstream components don't have character as they most certainly do, but they will not impart their character to the extent that speakers do to the overall system(which is why novices don't have a hard time hearing differences between speakers but don't always pick up as easily on changes to electronics). So don't expect the change to be "quantitatively" as different as changing speakers, but "qualitatively" a CD player may yield a bigger improvement depending on your system and tastes.
I'm saying all this because if you don't like the "character" of the sound of your system the biggest absolute(note, not qualitative but rather quantitative) change you can make is with regard to speakers. If, however, you basically like the sound of your system but want to improve it then I subscribe to "the chain is only as strong as the weakest link" theory, and it's up to you to discover which that is through trial, error, and playing a hunch.
I think you're on the right track looking at the source(assuming you're happy with the "character" of your system), and given your level of equipment I'd think you would hear a fairly dramatic improvement to your system by upgrading to a better source component, but don't expect the change to necessarily hit you over the head immediately--it may or may not. Some things to listen for would be not necessarily the level of detail but rather the way in which detail is presented--is it more natural/believable? Also there should be more clarity of space between players/instruments that allows them to more clearly exist individually. Bass may become tighter and better defined. Soundstage may expand in all directions, and elements at the rear of the stage especially may become more readily identifiable and easy to hear/place in space, and echos and reverb will tend to tail off in a more natural and extended way. Anyway, these are some things to listen for, and I bring them up because sometimes you need to listen into the music more to pick up these changes.
So this has a lot to do with perspective and expectations, and the above is meant to help provide some of the former while also managing some of the latter--hope it helps and best of luck.
By the way, my guess is Sean's referring to an EVS Millennium DAC as I had a VERY similar experience when I got mine. Talk about dramatic improvements. Come on Sean--fess up.
Tim