A Strat will never sound like a Les Paul. There is a lot more to the sound of an LP than the pickups. In fact, you can not get that sound without the weight. A large part of the LP sound is from the thick mahogany body, and mahogany weighs a lot more than alder, plus LP's are thicker. Add to that the maple top on LP's (which is a very heavy wood), and you are looking at a guitar which is going to be heavy. That weight is a big part of the sound.
Strats also have the wrong scale length for the LP sound (Strats are 25.5 inches, and LP's are 24.65 inches). Though it is often overlooked by many people, this makes a huge difference in the sound of a guitar. Additionally, the bridges are very different, which makes a big difference in the sound.
Without major modification, you can not even get a humbucker sound out of a Strat, as they won’t fit the pickup cavities. The single coil sized humbuckers will not do it. The problem is the length of string which the pickup "picks up," so to speak. With a full sized humbucker, the pickup senses about twice as much of the string, which leads to a variety of phase cancellation issues in the upper end harmonics. (If you think harmonics are just those bell like tones when you barley touch a guitar string, Google the "Harmonic Overtone Series." It is something you should know.) The single coil sized humbuckers can not recreate that sound, because they do not pickup as much of the string.
Now, don't get me wrong, I like the sound of a Strat with humbuckers. They just don't sound anything like a LP. I mean, starts with humbuckers is basically what I build, and is what I play.
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