GK MB150 question, boost knob

[snowdan]

you know, there is this "boost" knob between EQ and chorus.

the manual refers to it as "adding low end bite".

so: is it really colouring the sound (boosting lows or so) or is it a sonically neutral gain stage?

 

[snowdan]

still wondering.

 

[fdeck]

"Boost" controls gain going into a Class-A JFET gain stage. Turning it up allows you to push that stage into asymmetrical soft clipping, similar to a tube preamp. I don't think it boosts the lows, but I will measure it tonight and let you know.

 

[fdeck]

I checked it out with my free spectrum analyzer program. The "boost" control does not change the frequency response at all. It is purely a distortion knob.