Low cut filter:
This is a simple passive RC high pass filter. Frequency cut ranges from 1/
(2xPIx(R6+BASS1)xC5) = 1591,55Hz to 31,2Hz.
When clipped the bass frequency creates more harsh fuzzy sounding harmonics.
Placing this high pass filter helps to remove some of them before the gain stage.
You should know that common overdrives for guitars cuts around 300-400Hz.
Gain stage:
C11 is a decoupling cap.
This kind of gain/clipping gain stage is very common, it is used in the tube
screamer pedal.
First, resistances R5, R7 and pot TGAIN1 set the gain of the stage:
Gain=(1+R7/R5). TGAIN1 being 500koHms, the gain can thus go from x2
to x501.
The C8 capacitor forms a low pass filter with TGAIN1 pot and R7 at cut off
frequency F=1/(2*pi*C8*(R7)). This is used to prevent high frequency
feedback when the gain is setup very high. When Tgain1 is at the maximum the cut
off frequency is 9626Hz.
Copyright Zorg Effects G.Denneulin december 2015 – For non commercial use only.
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