Milbert AmplifiersMilbert Amplifiers is an American electronics manufacturer based in Gaithersburg, Maryland.WWW Official SiteHistory and productsMilbert manufactures audio equipments. It introduces its mobile vacuum-tube audio amplifier in 1986, which has been followed by several models collectively in continuous production for nearly 30 years. The company also produces vacuum-tube guitar and musical amplifiers using unique impedance conversion which is claimed to prolong tube operating lifetimes.