Ld1014d question about noise
 

In looking at this high power jfet I wonder if it might be suitable for a small low impedance source follower in the 50 to 100ma range. Does anyone know if it would be very noisy when used like that with a 500 ohm source impedance ?

What signal swing are desired?
In the --someVolt range i suppose noise will not be the problem.

I was thinking about 5v 50 ma at 15v drain to source with a 500 ohm input source resistance at 1k hrz.

For ~100 Ohm headphones?

Is this an amplifier for speakers??? :confused:

No.
50 mA idle current follower can't provide enough current to drive speakers.

Familiar with the Zen8? PassDiy

It has a high transconductance and it must have a large die area, so chances are its equivalent input voltage noise level will be quite low. Current noise will be low(*) as long as you reverse bias the gate, which will happen automatically at 50 mA to 100 mA.

(*): Regarding noise current, a smaller JFET will be even better, but you will only notice that at very high source impedances, like those of condenser microphone capsules without built-in amplifier.

Here's the Zen9 "noise" -- to get flat frequency response (into a 6 ohm passive load) I had to increase Vds to 2.12, and lower the current to 1.6A. Gain is 21dB.

I've run the LU1014 on its own, not yet satisfied with the results.

Here's the LU1014D all by itself, powered by Groner's ultra low noise current source (400pA/RtHz), adjusted to 50mA: