STUDER D19 MicVALVE Microphone Preamplifier. The item "STUDER D19 MicVALVE Microphone Preamplifier used amplifier audio MIC VALVE" is in sale since Monday, November 5, 2018. This item is in the category "Consumer Electronics\TV, Video & Home Audio\Home Audio\Receivers & Amplifiers\Amplifiers & Preamps". The seller is "bambootokyo" and is located in Nakano-ku. This item can be shipped worldwide.