Grombass is the one distortion/drive effect for bass that you will need. It has a wide range of sounds; from slightly boosted to synth- like distortion – always preserving the low ends!
The trick is done by NOT distorting the lowest frequencies. Just the ones above a certain freq. This keeps the punch and power. Do not suffer from the usual lack of bass response in a bass distortion.
Here is an overview over the controls:
Germanium: Lowest amount of distortion, a little dirty/warm in the background
LED: Gives more bass and less treble and most distortion
Silicon: A more trebled and hiss distortion
The switch “Muffler” is a filter that changes the mids and tops. This filter is dependent on the controller «Gear»
“Turbo” is the gain on the input.
“Gear” is a tone controller that controls the gain of the lower frequencies.
“Injection” is the output volume.
“Boost” is activated when the Boost toggle switch is pressed. This gives as you might guess… extra boost.
There is also an input for expression pedal. That gives you the ability to change the amount of gain (and reduce level to compensate) while you are playing on stage.
And there is a second output called “Clean”. This is an clean boosted output depending on the “Injection” and the “Boost”.
Besides these controls, there is a potmeter inside to adjust the input level – if you want to use it with an active bass.