Considering the title of this thread is "High Quality Audio Preamp", so far it's only consisted of really poorly designed basic opamp circuits.
Why use two opamps anyway? - all you're wanting to do is give a small boost to the output from a sound card, which is already low impedance and at a fairly high level. So you can feed the sound card directly into the volume control, then an opamp to give the gain, feeding the power amp. It's up to you if you want inverting or not, but in either case make sure the input impedance of the opamp is at least five times that of the volume control.