The new Studio Projects VTB1 is the ultimate in low cost mic preamplifier technology. Incorporating true class A/B switching, the VTB1 is a totally discrete circuit. Unique to the VTB1 is the "Tube Drive". The Tube Drive is a variable drive to a 12AX7, that allows the user to blend as little, or as much of the Tube Drive they want. This VTB1 allows the user the most flexibility of any mic preamplifier in it's price class.