Some people aren't too concerned with the quality of audio that comes from their headphones. They plug right into their computer or stereo and just let it fly. There are some who are even willing to listen to MP3s with the earbuds that come with the iPhone. For those that really care about the sound that's pumping into their ears, there's the PA-10.1D from Trends Audio. It acts as a preamp and amplifier for your headphones, giving you an improved audio experience.
The PA-10.1D is built for folks that like doing a bit of tweaking too. It comes stock with either a Russian 6H23n or USA 12AU7 tube, and is compatible with both 6DJ8/6922 and 12AU7 tubes. That means you can switch things around all you like to find the sound that's right for you. Trends Audio's PA-10.1D will be available in November for a price of $299.