Behringer's MIC500USB Audiophile Vacuum Tube Preamplifier affordably delivers high-end, tube-driven pre-amplification for all microphone, instrument, and line-level sources. The MIC500USB uses a hand-selected 12AX7 vacuum tube for exceptional warmth with a very low noise floor. You get balanced inputs and outputs on 1/4" TRS and XLR connectors, 48-volt phantom power, a phase reverse switch, and 20dB Pad for the utmost flexibility. Need more? The MIC500USB provides 16 preamp voicings through its built-in USB/audio interface and free audio recording software with 150 instrument/effect plug-ins that are downloadable directly from Behringer's site.