Run your amp hotter with the Master Volume Box! Designed to work with high wattage amplifiers, this passive attenuator allows you to achieve concert-quality tones at any volume level. No more compromising on your sound. With the Master Volume Box, you have complete control over your overall volume. Hook it up to your amp's effects loop (send/return) and unleash the full potential of your amplifier. It is like adding a master volume knob between your preamp and your power amp. Having the added master volume between your pre amp and power amp allows you to crank your gain and master volume on your amp, and control the overall output with the Master Volume Box.