Plenty of these exist, but every one I'm aware of is aimed at the higher end to audiophile end of the market, and based on the way you've asked your question I'm guessing (maybe wrongly, but anyway) that you're not looking to spend thousands to tens of thousands of dollars for a pre-amp.

Your best bet for an affordable solution is to look for an AV amp that has pre-outs (i.e. line level signal outputs for feeding external amplifiers or powered speakers). These are pretty common on Denon, Onkyo, mid- to high- end Sonys, etc.

Bob