This reminds me of the old Marshall Guitar Amp ads which ran "It comes out bigger and upsidedown." (Still one of my favorite posters.)
Whatever you want to call it, it's part of the process. For the most part, all standard active devices used as voltage amplifiers invert the signal which means if a positive voltage goes in it emerges as a larger but now negative signal. This leads to another simple point that a "preamp" is poorly named because it is an amp itself.
Phase inversion is inherant to the process. Everytime an audio signal passes through a gain stage, the polarity
(some refer to it as a 180degree in time phase change, whatever) of the signal is reversed. The output voltage moves in the opposite direction of the control Voltage. If you like tubes this reads as the grid voltage becomes more positive, the output plate voltage becomes less positive and visa versa. Mr. Marshall would add "and its bigger too."
I am happy to do my part to add to all the confusion.
Cheers,
I remain,
Whatever you want to call it, it's part of the process. For the most part, all standard active devices used as voltage amplifiers invert the signal which means if a positive voltage goes in it emerges as a larger but now negative signal. This leads to another simple point that a "preamp" is poorly named because it is an amp itself.
Phase inversion is inherant to the process. Everytime an audio signal passes through a gain stage, the polarity
(some refer to it as a 180degree in time phase change, whatever) of the signal is reversed. The output voltage moves in the opposite direction of the control Voltage. If you like tubes this reads as the grid voltage becomes more positive, the output plate voltage becomes less positive and visa versa. Mr. Marshall would add "and its bigger too."
I am happy to do my part to add to all the confusion.
Cheers,
I remain,