jdduffield
Active member
I realize this is a noob question, but I’m trying to understand something about the audio signal path vs the power signal path. I’ve always thought (before I got into this stuff) that the audio and power path are joined at some point within a circuit. Now I’m not so sure.
Things I’ve noticed is that the reasons we introduce 9 volts into a circuit is because of either a chip, a transistor, an op amp, or something that we are powering. Often that is done to boost a signal up. In other words, a passive pedal can attenuate a signal, turning it down, but it can never make the signal louder without power.
I understand that what comes out of our guitar under normal circumstances is a very quiet signal. The sound waves created by our strumming are converted into an electrical signal through the process of vibrations being detected by the pickup’s magnetic field. At that point we have electrical sine waves to work with that are are quiet but can be sent through the cable, and they enter the circuit which become the beginning of the “audio path”.
The positive 9 volts enters the circuit at some other point on the board and becomes the beginning of the “power path”.
I’ve heard that we are to keep those paths separate. My question is do we ever bring those two paths together? Is it more like we just use it to power things that lift the signal in some other way (transistors, op amps, etc)? I notice we typically power one of the legs of those devices. Do those things handle mixing the two paths together for us? (I imagine if they do it would be very surgical, small amounts of voltage.) Or is there something I’m missing, like something having to do with current or something else?
Things I’ve noticed is that the reasons we introduce 9 volts into a circuit is because of either a chip, a transistor, an op amp, or something that we are powering. Often that is done to boost a signal up. In other words, a passive pedal can attenuate a signal, turning it down, but it can never make the signal louder without power.
I understand that what comes out of our guitar under normal circumstances is a very quiet signal. The sound waves created by our strumming are converted into an electrical signal through the process of vibrations being detected by the pickup’s magnetic field. At that point we have electrical sine waves to work with that are are quiet but can be sent through the cable, and they enter the circuit which become the beginning of the “audio path”.
The positive 9 volts enters the circuit at some other point on the board and becomes the beginning of the “power path”.
I’ve heard that we are to keep those paths separate. My question is do we ever bring those two paths together? Is it more like we just use it to power things that lift the signal in some other way (transistors, op amps, etc)? I notice we typically power one of the legs of those devices. Do those things handle mixing the two paths together for us? (I imagine if they do it would be very surgical, small amounts of voltage.) Or is there something I’m missing, like something having to do with current or something else?
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