Recommend a passive preamp route

Hi- I'm looking for some expert feedback on the last piece of my stereo setup. I'm running the following:

PC (FLAC files) -> Chromecast audio -> Parasound HCA-1000 -> pair of Large Advent speakers

My general strategy here is solid but simple. None of these components are wildly awesome, but I think thus far I've avoided any particularly weak links. I think it would be hard to improve the overall sound without spending exponentially more money.

Anyway, the issue is that my only volume control here is on the PC or phone used to trigger the Chromecast. These aren't dedicated sources, so it's pretty easy to imagine that sooner or later I or someone else will accidentally not lower the volume prior to pressing play, and bleeding eardrums will result. Right now I have the level adjustments on the power amp all the way up, because that seems to be recommended on a THX amp and just as general practice. Those pots are also a little scratchy midrange.

So, I need a preamp, just for volume control. I'm just going to use the one input and so don't need any input switching. The Chromecast puts out 2V and the amp only needs 1.1V for full performance, so I don't need any gain. The only feature I might like to have would be an extra set of outputs, in case someday I wanted to bi-amp.

I've found some common options online- Goldpoint, Pass B1 seemingly being some of the cheapest. Even so, at $350 I'd nearly have more in the volume knob with a Goldpoint than I have in the entire rest of the system combined. What should I do to get the adjustment I need, without compromising my signal path, but also without going way overboard on cost? Is impedance matching something I need to worry about at this level of quality?

Thanks!