JHS Spring Tank ReverbThe Spring Tank gives you the ability to create the perfect spring reverb for your sound with controls for Depth, Length, Highs, Boost (to control your overall volume), and two independent and switchable reverb mixes called Tank 1 and Tank 2. The Depth controls the size of the room, while Length controls how long the reverb reverberates. Highs gives you the ability to control the tone of the reverb by adding or subtracting high frequencies. Tank 1