This amp is a little powerhouse, that is great for both electric and upright basses. The Balanced XLR output is a true balanced output. No front panel controls affect its signal. The tone and output level are controlled only by the instrument plugged into one of the input jacks. Two separate and independent input jacks are provided so that the best signal-to-noise ratio can be obtained without overloading the preamp section. The Passive input has over twice the gain than that of the Active input. Both inputs can be used simultaneously without affecting the volume or tone of the other. One use of these inputs would be to plug your bass into the Passive input and practice along with a drum machine by plugging it into the Active input. The Workingman's 12 Tone Control section is a three-band set of level controls centered around the frequencies 80 Hz (Bass), 800 Hz (Mid Range) and 5kHz (Treble). Each control can cut or boost its band a maximum of 15dB. Each control has a flat (center “click") position that defeats its function. In this position, the tone controls are inactive. Midnight Blue Carpeting with Stack Lock CornersVibration-Free GrillDiscrete solid state front endAutomatic compressor/limiterSide Chain Effects Loop