Well many of us do replace old LEDs with newer more efficient ones...
[I am under the impression because of the questions you have asked that you are new to LEDs/ Electronics. So I'm going to try and explain what I think will help answer your question.]
LEDs are generally driven by a circuit that delivers a specific voltage. Most white LEDs run at around 3.0 to 4.0 volts depending on which LED it is, what bin it is, how much current we pass thru it. (Don't worry about that too much for now)
Watts is determined by how many volts multiplied by how many amps are run thru the circuit. W = V * A So if we're running an LED that needs 3 volts at a current of 1/3amps we use a total of 1 watt of power.
The efficiency of the LED determines how bright it will be.
If we take an LED and run it at 1 watt and take that same LED and run it at 3 watts it will be brighter [assuming that LED is capable of handling the increased current (amps) that are required to make it 3 watts]
I can also make my light brighter by using a better, more efficient LED and not changing the watts.
Perhaps let's take an example. I reciently bought a
Black Diamond Zenix IQ Headlamp. It contains an old 1 watt Lumileds Luxeon I emitter.
Without buying an entire new circuit board and re-wiring the whole thing there is no way I can make it into a 3 watt. The circuit determines how many watts the headlamp is. Not the LED. Now I am making it brighter by taking out the antiquated Luxeon I LED and installing a Seoul Semiconductor LED (SSC). Because of advancements in LED Technology the SSC is more efficient, and so for the same amount of watts used I get approximately double the light output.
Now there are many flashlight modders who do replace circuits to drive LEDs flashlights with more or less current (amps); which means that overall watts is changed as well because the voltage needed to light up an LED stays
relatively the same. This is one of the key aspects of CPF: modding LED lights by using different circuits. It requires much more experience and knowledge than just swapping LED emitters. It is far less common to do this with headlamps due to their odd shape and generally inferior construction.
Now with a bit of soldering could you take the PT Apex, de-solder the antiquated 3 watt Luxeon III LED and put in a newer SSC? Yes, it isn't too hard. Will it make it brighter? Yes you'll get over 100 lumens.
Use the search function at the bottom (not the top one) of the headlamps section and search for "Apex" and you should find tons of discussion on doing this. Many people have done it and it makes about the best headlamp available at this time.
Again if you already know all of this I'm sorry for the "lecture," please restate the question. But if you're new to this stuff I hope this helps.
