Check the listing for details. PRESONUS ACOUSTI-Q TUBE PREAMP. Condition: Used. Listed at 299.00 USD. A perfect solution for acoustic musicians, helping to take their personal style and sound to new heights! Lets you choose between a single (piezo pickup) or dual (piezo pickup and mini-internal microphones) source. With 2 sources, you can blend the signals to achieve the perfect mix. Guitars, woodwinds, basses, brass instruments ” virtually any acoustic instrument can benefit from the warm tube sound. Equipped with 2 dual-servo microphone pre-amplifiers with separate gain controls for input, a phase switch, a 12V phantom power supply to accommodate miniature, internal condenser microphones, a variable notch filter, sweepable mid-band EQ, as well as low- and high-shelving EQ controls. The master output section lets you set 2 separate volumes, one for normal volume and the other, a boost, for solos. Great for guitar, bass, woodwinds . . . virtually any acoustic instrument.