Thank.In this Marco's example he is determined with given values of power supply.
So that is OK to try - but that will be not the "true" sound of circuit and this tube.
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The cathode follower is complete different circuit. Gain is +A<=1. +A means that circuit do not shift phase for 180deg. Phase in = Phase out.
The input signal is always a bit higher than output. BUT the output impedance is smaller than anode follower.
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for 47K use minimum of 2 or 2.2uF capacitance. Calculate CR fiter with -3db@1.6Hz, for good phase shift and BW (that is -0.25Hz@20Hz) with standard formula.
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Next stage input impedance is affecting value of load line. More ralistic load line is RL in parallel with next stage Rinput. So Use higher Rload value to match decease of Rload with Rin-next stage.
I know that.
But i wonder why on a lot of schematics input voltage (grid) is lower that output voltage.
For me and for a 6n8s tube in cathode follower A=~0,95.
That means when grid voltage is 120v, output voltage is 114v(without load).
I'm wrong ?
Marco, you're confusing AC and DC voltages, I'm afraid.
AC (signal) gain of the cathode follower is less than 1, that's correct.
But for the tube to be biased properly, the grid should be negative with the respect to the cathode, i.e. grid DC voltage should be lower than cathode DC voltage.
AC (signal) gain of the cathode follower is less than 1, that's correct.
But for the tube to be biased properly, the grid should be negative with the respect to the cathode, i.e. grid DC voltage should be lower than cathode DC voltage.
Hello, what kind of potentiometer should i use for a tone control please?
Stéréo and logaritmic should be fine but I have readed that those who are builded with carbon film are noisy, isn't it ?
Regards
Stéréo and logaritmic should be fine but I have readed that those who are builded with carbon film are noisy, isn't it ?
Regards