response curve 134 in general a lower capacitive value for one of the capacitors 56 63 will cause the corner frequencies f 1 f 2 and f 3 to shift toward higher frequencies for example in order to provide a range of effects through the selection of one of the n capacitors with switch 55 for audio signal applications the capacitor with the lowest value preferably moves the 12 db octave slope up to about 4 to 5 khz on the other hand the capacitor with the highest capacitive value selected by switch 55 preferably moves the 12 db octave slope down to about 30 hz thus the lower frequencies that the 12 db octave portion of the frequency response curve operates on can range from about 30 hz to about 5 khz the actual selection will depend upon the preferences of the user fig6 illustrates the ability to change the gain characteristics of that portion of the frequency response curve above the corner frequency f 4 the feedback components capacitor 83 and resistor 84 across op amp 80 normally determine the frequency of corner frequency f 4 a when switch 75 is in the position shown in fig3 this results in the frequency response graph shown by graph 136 however when switch 75 is in the opposite position to that shown in fig3 capacitor 69 will change the frequency response to a graph such as graph 135 in fig6 note that in graph 135 capacitor 69 also causes an increase in the corner frequency f 4 b above that of f 4 a and an increase in the higher frequency gain above that of graph 136 fig7 is a composite of the.