TechPowerUp posted a review on the Sennheiser GSX 1000 Audio Amplifier
A quote from the article:
The Sennheiser GSX 1000 Audio Amplifier is a beautiful external USB sound card equipped with the best 7.1 virtual surround sound system we've heard so far, and a host of other interesting features primarily aimed towards hardcore gaming.Sennheiser GSX 1000 Audio Amplifier Review @ TechPowerUp