Redefining Bass with Precision Designed for ultimate sonic quality and portability, the M Combo Series defines excellence in Analog bass tones and precision. Featuring custom-made Eminence® speakers and powered by an efficient 500 W class D power module, the M Combo Series are perfect for the musician demanding premium analog character across venues, rehearsals, and home setups. Top Panel FeaturesInput Use this jack to connect your instrument via a standard ¼” mono cable. Headphone Output Connect your Headphones and enjoy the analog cabinet emulation. Passive/Active Use this push-button switch to change from passive to active mode. If your bass is active it can have a hotter signal making the amp to distort early (feel free to use if such additional distortion is desired). Compression Controls the amount of dynamic compression. The make up gain is adjusted automatically. Drive Controls the amount of distortion that the Microtubes Engine will deliver. Press to select the drive mode: OFF/Vintage Microtubes /Microtubes B3K. Blend Use this knob to mix between the Clean signal and the Distortion signal. Level Controls Microtubes Engine’s output volume. Low ±12 dB @ Low shelf Low Mids ±12 dB @ 500 Hz/1 kHz Press to select the frequency Hi Mids ±12dB @ 1.5 kHz / 3 kHz Press to select the frequency Treble ±12dB @ High shelf Master Use this knob to control the overall volume of the combo. Press for Mute.