I will be using some recently-acquired headphones (Audio-Technica ATH-M50S) and a recently-ordered standalone headphone amplifier. Was thinking about getting a CSP2+ to use as a preamp.  If it turns out I prefer the standalone headphone amp over the Decware and decide I just want to use the Decware as a regular preamp, what is the best way to hook up a headphone amp to it given that there is no tape out?

I thought about ordering an additional output and running that into the headphone amp with the Decware's volume cranked up but would prefer a regular tape out that doesn't go thru the volume control of the Decware.  I need a big transisitor amp so getting a TABOO as well won't work for me.  I am starting to have a brain cramp about this so have I missed some easier option?  Aside from headphones I normally only use one input (CD) and one output (to power amp)