Ultrasound Amplifiers has reintroduced its Ultrasound DS4 acoustic amp. Designed to amplify fiddles, mandolins, guitars, and other acoustic instrument, it uses two 8″ speakers and produces 50 watts of power. Its master section includes a master Volume control, 16 effects, and a three-way toggle to assign effects to either channel or both. The rear panel has send and return jacks, effects footswitch jack, line out, direct out, RCA Tape/CD input, and Tape/CD level controller. Channel has a dual XLR and 1/4″ in with phantom power, Volume control, and Bass and Treble EQ controls. Channel two adds a notch filter. For more, visit ultrasoundamps.com.