DISTORTION PEDAL DESIGN, got some questions...
I am designing a guitar distortion pedal. It is my aim to produce (harsh) symmetrical and asymmetrical clipping, with enough gain to also produce near-square output waveforms. I'm trying to keep it as simple as I can. I just want to get it to 'work' without risk of damaging a guitar amplifier first, then I'll worry about improving the sound from there.
This is the design so far...
*The following is what i 'think' the circuit is doing but correct me if I'm wrong*
The plan is to use a 741 opamp (non-inverting) to amplify the input signal. There is a pot to control the gain (2-52?) of the opamp. A 9V battery is being used to power the opamp and provide a voltage divider (ref voltage?) at opamp input... I understand the max output (amplitude) of the opamp will be limited, hence once the opamp output exceeds this, the signal will be clipped evenly top and bottom. A second pot is at the output end of the circuit to allow volume control. There are capacitors at either end of the circuit (coupling). And there is a switch that can incorperate a diode into the circuit, which would produce asymmetrical clipping.
I built the circuit on MULTISIM using a signal generator as my (guitar) input signal to the circuit and used an oscilloscope to veiw the output waveform. The only adjustment I made from the above circuit is I replaced the 1k resister below the gain pot for a 500, to allow a larger gain soes to amplify smaller inputs enough to ensure they clip. The signal appears to process as I had hoped (clipping at approx +/- 3.6V and at -0.6V with diode) and the volueme pot seems to work, but will this circuit work in the context of a guitar distortion pedal?
*Are there any obvious faults with this design?...*
My main concern is impedance matching...I read somewhere that the input/output of a distortion pedal is high impedance (which the opamp can take, right?, but the output impedance is low?) I'm not sure if/how to match it at the output. What is the result of not or incorrectly matching the impedences? Also, not 100% sure if my capacitor (and resistor) values are viable for this circuit...
ANY AND ALL ADVICE WELCOME!
I am designing a guitar distortion pedal. It is my aim to produce (harsh) symmetrical and asymmetrical clipping, with enough gain to also produce near-square output waveforms. I'm trying to keep it as simple as I can. I just want to get it to 'work' without risk of damaging a guitar amplifier first, then I'll worry about improving the sound from there.
This is the design so far...
*The following is what i 'think' the circuit is doing but correct me if I'm wrong*
The plan is to use a 741 opamp (non-inverting) to amplify the input signal. There is a pot to control the gain (2-52?) of the opamp. A 9V battery is being used to power the opamp and provide a voltage divider (ref voltage?) at opamp input... I understand the max output (amplitude) of the opamp will be limited, hence once the opamp output exceeds this, the signal will be clipped evenly top and bottom. A second pot is at the output end of the circuit to allow volume control. There are capacitors at either end of the circuit (coupling). And there is a switch that can incorperate a diode into the circuit, which would produce asymmetrical clipping.
I built the circuit on MULTISIM using a signal generator as my (guitar) input signal to the circuit and used an oscilloscope to veiw the output waveform. The only adjustment I made from the above circuit is I replaced the 1k resister below the gain pot for a 500, to allow a larger gain soes to amplify smaller inputs enough to ensure they clip. The signal appears to process as I had hoped (clipping at approx +/- 3.6V and at -0.6V with diode) and the volueme pot seems to work, but will this circuit work in the context of a guitar distortion pedal?
*Are there any obvious faults with this design?...*
My main concern is impedance matching...I read somewhere that the input/output of a distortion pedal is high impedance (which the opamp can take, right?, but the output impedance is low?) I'm not sure if/how to match it at the output. What is the result of not or incorrectly matching the impedences? Also, not 100% sure if my capacitor (and resistor) values are viable for this circuit...
ANY AND ALL ADVICE WELCOME!
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