I have been fiddling around with the SR4006 and there is a Mid Q nob between the treble and mid . There is an eq on and off switch on the body too. I am guessing this midQ widens or shortens the mid frequencies. It seems to do very little. If I turn off the eq switch, it changes the tone a little bit but nothing like boost or cut when the eq is on. What am I doing wrong or is this thing busted or is this the way this nob works? Also does eq swith off mean it is in passive mode?