How do you make a Heaphone output on the amp?


Say you build a standard solid amp with differential input, voltage stage amplification and a good class AB power output stage that is designen for low impedance speaker. What if you would like to use it to drive a couple of headphones?
Can this be done by just adding a voltage divider with two resistors on the output? Or is it done by switching to another gain? Or is the signal taken directly from the preamp?
ALL the above.....
There is no rule from where you get the signal from, as long as you don't degrade the integrity of the signal in the process....... Looking at various amps with headphone monitor, you will see many methods..
I prefer to use a seperate driver/buffer exclusively for the headphones..and tap off the last driver stage prior to the PA sections...
Then you can put in a volume pot or "soft" standy-by for the PA section....this way the amplifier can double as a headphone amp and not blow the walls down at 2:00am ;)