Do headphone outs of full size speaker amps have the same output as its regular outputs?
It seems really hard to find any specs on the headphone outs in particular.
There seems to be a lot good looking speaker amps in the $3-400 range from pioneer, onkyo, yamaha, denon, marantz, nad.. etc.
They all have more than enough watt, but i cant find any details about their headphone out power.
No, speaker taps deliver exponentially more power. The headphone out has a series of resistors and chokes between it and the amplifier output stage to lower the current and voltage levels.
Please come over to the Vintage amp thread for more info. Depending on what is available in your area we can steer you to the best possible choice.