Audionet has a complete line of electronics and its not your run-of-mill stuff. Perhaps most intriguing are the DSP-capabilities that are built in to a number of their products including their DNC Digital Network Client Server ($8,990). In brief, their free Java-based Carma software allows you to adjust the frequency response curves of your playback using a very intuitive GUI and you can save these settings on the fly to the Digital Network Client or other enabled Audionet devices.
Other computer audio related devices from Audionet include the DNA Digital Network Amplifier ($16,990) that is a 160W/channel integrated amplifier and UPnP streamer that accepts WAV (up to 96kHz/24Bit), FLAC (96kHz/24Bit), MP3, AAC, WMA, and OGG-Vorbis file formats.
The Audionet DNP Reference Digital Network Preamplifier ($15,990) is a preamp/USB DAC/UPnP Streamer that also includes DSP using the free Audionet software.