I've seen some preamp projects with n-channel JFET (audio preamp) were I could not understand the biasing process.
By the books the VGS needs to be negative related to the source to set a quiescent point.
But on these projects the source is linked directly to Ground (no RS) and the gate is also linked to ground by a resistor (RG).
With this config both (Gate and Source) should be at 0V, so how this operates without distortion??? Mainly during the positive cycle of the input signal....
I'm attaching the link for a circuit sample:
http://diyaudioprojects.com/Solid/JFET-Phono-Preamplifier-Kit/Le-Pacific-Phono-Preamp-Schematic.png
Thanks in advance!
By the books the VGS needs to be negative related to the source to set a quiescent point.
But on these projects the source is linked directly to Ground (no RS) and the gate is also linked to ground by a resistor (RG).
With this config both (Gate and Source) should be at 0V, so how this operates without distortion??? Mainly during the positive cycle of the input signal....
I'm attaching the link for a circuit sample:
http://diyaudioprojects.com/Solid/JFET-Phono-Preamplifier-Kit/Le-Pacific-Phono-Preamp-Schematic.png
Thanks in advance!