Question on stereo output on headphone amp

[CodeMonk]

I recently built a headphone amp.
Not the Ruby, but I am looking at that one as well.
Anyway, I wanted to add another input for CD player, etc and still keep the stereo sound.
So the idea I came up with was pretty damn simple.
I hooked the amp output to a 1k trimpot (I scavenged that, as well as alot of my prototype parts from an old stereo).
I hooked the output the the wiper and the headphone right and left channels to the other tabs.
I then hooked the CD input jack to the headphone output jack pin for pin.

It works fine. I still get the stereo sound from my stereo, and my guitar comes out fine on both sides.

Seems like a pretty simple solution to what I thought would be a complex problem.

Or am I missing something here?
I thought about separate buffers for for the right and left channels to separate them from the mono amp output. But this was simple and so far is working fine.