Has anyone measured the noise on them? They've been around for a while and frankly for theoretical noise they look better (larger Beta, the transconductance parameter) than the first batch of LSJ74's. The ones given out with Linear Audio were better.

I wrote a little JFET parameter extractor in Python using the Analog Discovery USB data acquisition box. I measure Vgs vs. Id and fit it to the ideal JFET equation. The LSK177 fits almost perfectly, in the picture the measured vs. formula almost lie on top of each other. The red plot is the difference vs Vgs. In general there is a deviation at the low end due to sub-threshold effects (making an accurate direct measurement of Vp almost impossible) and at the high end by the parasitic source resistance.

I wrote a little JFET parameter extractor in Python using the Analog Discovery USB data acquisition box. I measure Vgs vs. Id and fit it to the ideal JFET equation. The LSK177 fits almost perfectly, in the picture the measured vs. formula almost lie on top of each other. The red plot is the difference vs Vgs. In general there is a deviation at the low end due to sub-threshold effects (making an accurate direct measurement of Vp almost impossible) and at the high end by the parasitic source resistance.

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