Universal Audio 4-710d 4-Channel Preamp - Used. Used Universal Audio 4-710d 4-Channel Preamp in great condition and perfect working order. Be sure to add JRR Shop to your favorites list. & check out our other items. The item "Universal Audio 4-710d 4-Channel Preamp Used New JRR Shop" is in sale since Monday, November 09, 2015.This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Preamps & Channel Strips". The seller is "jrr_shop" and is located in Fountain Valley, California. This item can be shipped to North, South, or Latin America, to all countries in Europe, to all countries in continental Asia, to Australia.