Rolls RP520 Bellari Dual Tube Mic Preamp 真空管麥克風及樂器雙聲道前級放大，每聲道單管直通式放大，用在樂器吉他上最主耍的是可加上真空管的音色。這机己有15年歷史了二手很便宜，試了還是很不錯的下次試試麥克風
Product: Rolls RP520 Bellari Dual Tube Mic Preamp

Rolls' Bellari RP520 dual tube mic preamp is identical to the RP220 except for the analog meters, and gold face plate. It has the smooth yet punchy characteristics that drive vocal tracks to the front, warm up any digital mix, and yields up to 6 dB more gain before feedback for the live user. The pristine sound is achieved by running the tubes at a high 250 volt plate voltage.~~~~~~~~~~~~~