Tone Stack
How The Guitar Amp Tone Stack Work | ||||||||||||||||||||||||||||||||||||||||
Tone stack is important part of guitar amp , which directly sculpts the tone of guitar amp.If you want to play guitar better, it is important to know deeply about tone stack, how does it work and how to adjust it. Audio filter reviews | ||||||||||||||||||||||||||||||||||||||||
High pass filter has the capacitor first followed by a resistor connected to ground. A high pass filter allows high frequencies to pass but blocks low frequencies. | ||||||||||||||||||||||||||||||||||||||||
Tone stack overview | ||||||||||||||||||||||||||||||||||||||||
Tone stack is by one low pass and three high pass filters. The Tone Slope Resistor RS is important part in tone stack,it takes two important roles in tone stack.
The cutoff frequency of high pass filter controlled by RB varies between 7.2Hz and 361Hz. With the RB full up the bass high pass filter only blocks frequencies below 7.2Hz so all guitar and bass frequencies get through. With the RB full down the filter blocks frequencies below 361Hz so most of the bass is filtered out. The cutoff frequency of high pass filter controlled by RM varies between 361Hz to infinitely high. With the RM full up the mid high pass filter only blocks frequencies below 361Hz.With the RM full down the mid filter blocks all frequencies. Freq flow in tone stack below. | ||||||||||||||||||||||||||||||||||||||||
RM works in tone stack | ||||||||||||||||||||||||||||||||||||||||
The combination of the low pass filter which formed by RS+CM and high pass filters which formed by CM+ RM creates a band pass filter. So only mid freqs signals pass through. RB works in tone stack | ||||||||||||||||||||||||||||||||||||||||
RS+ CM form low pass filter, The bass and mid freq signals pass on to the CB. CB + (RB+ RM) form high pass filter, the RB blocks low frequencies. By filtering the guitar audio through a low pass filter followed by a high pass filter (Bass control) a variable band pass filter is created that only affects bass freq signals. With the bass high pass filter's resistance of RB1M + RM 20K = 1.020M with the RB max gives a cutoff frequency of 7.2Hz. With the bass high pass filter's resistance of 0 RB +RM 20K = 20K with the RB minimum gives a cutoff frequency of 361Hz. Note the mid filter's lowest cutoff frequency is 361Hz so the bass and mid filters match up perfectly. The RM below the wiper comes after the low pass filter let some mid and high freq signals pass through the filter to the CB. The RB has no effect when the RM and RT are full down RT works in tone stack | ||||||||||||||||||||||||||||||||||||||||
CT + (RT+ RM ) form high pass filter, the high freq signals pass across the top of the tone stack.RS +CM form low pass filter, the bass and mid freq signal flow through the RS and CB around to the RT.
The RB setting has no effect on the treble high pass filter cutoff frequency because the treble filter's path to ground can flow through the CB and CM to flow around the Bass Pot. Conclusion
The Marshall midrange control offers more midrange at the top end of the control setting, but a more accelerated gain variation depending on the setting. The 5F6-A, on the other hand, has less maximum midrange, but finer midrange control. |