I've been building myself a simple amplifier (Of which I will post more details about in a separate thread) which uses a TDA2050 chip of the power amp and a few JFETs and NPN transistors in the pre amp. I've breadboarded it and it works fine, but I don't believe the bias of my FETs is correct. I've googled and googled, read various websites and have gotten nowhere, everyone seems to have different methods of finding the correct bias. Can someone please help? I'm using J202 JFETs, datasheet is here:
http://www.experimentalistsanonymous.com/diy/Datasheets/J201.pdf
My supply voltage is 35VDC. I'm currently using 33K Drain and 1K Source. My VDS is 20V which is roughly ok, but the JFET is only drawing 0.46mA. The datasheet states it should be between 0.9 and 4.5mA.
http://www.experimentalistsanonymous.com/diy/Datasheets/J201.pdf
My supply voltage is 35VDC. I'm currently using 33K Drain and 1K Source. My VDS is 20V which is roughly ok, but the JFET is only drawing 0.46mA. The datasheet states it should be between 0.9 and 4.5mA.