Warm Audio WA12 MKII Mic/Instrument Preamp Features: Fully discrete design with a robust 71dB of gain to power all your mics even ribbons High-voltage X731 operational amplifier, based on the classic Melcor 1731 Tone button gives you tonal versatility by switching input impedance from 600 to 150 ohms 48-volt phantom power, 20dB pad, and polarity invert switches Mic level balanced input: XLR or 1/4 TRS Balanced outputs: XLR and 1/4 TRS 2 Mohms true hi-Z input on front panel great for guitars, bass, keyboards Custom-designed Cinemag input and output transformers LED gain indicator