WisWinDa Pro RCA Passive Preamp was buid-in dual quality ground loop isolators which could eliminate the ground loop hum noise and optimized the audio performance. Hep to improve audio transmission efficiency and reduce signal loss and compression. Hot-swap design, easy and convenient for using in different audio system situations. WisWinDa Pro RCA audio Step-Up transformer is very compatible with CD players, cellphones, PC and tube amplifiers. Could be widely used in different audio systems, whether in home/office theaters or professional recording studios. WisWinDa Pro RCA Passive Preamp 1:2 Step-Up Transformer Hot-swap design Build-in Dual Audio Isolation Transformers (WDAMP-PRORCA-011A)