Lots of things in an amplifier are held at DC levels - for example the main power supplies, bias for cascode transistors etc. These aren't generally seen as being in the signal path, as there is no appreciable change in voltage on them, so you can use non-linear capacitors to smooth them out.
For things that have changing voltage (ie are in the signal path), capacitors that vary with voltage introduce distortion products.
For things that have changing voltage (ie are in the signal path), capacitors that vary with voltage introduce distortion products.
The 'Signal Path' is the route the applied audio signal, (music will do to illustrate this example), follows from input to output.
From the MM cartridge to the RIAA pre amp. The pre amp converts the "small signal" to "line level" and then to the amplifier where it is converted to power the loud speakers.
The path the audio signal has taken is called 'Signal Path'
The same applies to RF Transmitters and even DC levels can follow the same path either by design or when they are not wanted due to a faulty DC blocking capacitor in the 'signal path'.
Hope that helps.
From the MM cartridge to the RIAA pre amp. The pre amp converts the "small signal" to "line level" and then to the amplifier where it is converted to power the loud speakers.
The path the audio signal has taken is called 'Signal Path'
The same applies to RF Transmitters and even DC levels can follow the same path either by design or when they are not wanted due to a faulty DC blocking capacitor in the 'signal path'.
Hope that helps.
Signal Path is a term which is often used, but mostly by people who do not understand what it means and its limitations. A common error is to assume that components in series with the signal are in the signal path, but those in shunt are not.
Better to think in terms of proximity to the signal path, not 'in' or 'out'. Components which the signal travels through in its journey from input to output are clearly in the signal path. All components directly connected to this are also in the signal path (so this catches the shunt ones too). Many components beyond these are certainly sufficiently close to the signal path to affect the signal. Power supply components may or may not be relevant, depending on the design details. Feedback components are in the signal path, including all items in any DC servo - which people sometimes use in the mistaken belief that a servo eliminates capacitors from the signal path (it merely hides them where newbies stop worrying).
Better to think in terms of proximity to the signal path, not 'in' or 'out'. Components which the signal travels through in its journey from input to output are clearly in the signal path. All components directly connected to this are also in the signal path (so this catches the shunt ones too). Many components beyond these are certainly sufficiently close to the signal path to affect the signal. Power supply components may or may not be relevant, depending on the design details. Feedback components are in the signal path, including all items in any DC servo - which people sometimes use in the mistaken belief that a servo eliminates capacitors from the signal path (it merely hides them where newbies stop worrying).
Any component in the amplifier that sees an AC voltage across it as part of intended operation is considered a part of the signal path. The sum of these components is what forms the signal path. One cannot exist without the other. In general, almost all components produce some distortion when subjected to an AC signal. Some may be insignificant, others quite obvious.
There are also components that see AC voltages without being intended, but are unavoidable due to the way electronics works (such as bypass capacitors in Class AB amplifiers). Understanding of how those voltages are generated and how to deal with them, is also critical to a making good amplifier.
There are very few components in an amplifier that are not subjected to some degree of AC voltages. If you probe the power supply capacitors with an oscilloscope, you will see some degree of AC ripple, and some degree of signal-modulated supply currents.
There are also components that see AC voltages without being intended, but are unavoidable due to the way electronics works (such as bypass capacitors in Class AB amplifiers). Understanding of how those voltages are generated and how to deal with them, is also critical to a making good amplifier.
There are very few components in an amplifier that are not subjected to some degree of AC voltages. If you probe the power supply capacitors with an oscilloscope, you will see some degree of AC ripple, and some degree of signal-modulated supply currents.
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