Ah, the smell of solder,

[Jeroen Belleman]

George Herold wrote:

On Saturday, February 15, 2020 at 7:22:14 AM UTC-5, Phil Hobbs wrote:
[...]

A resistor in the emitter reduces the shot noise current by a factor of
IR/26 mV due to negative feedback (emitter degeneration), until base
current shot noise becomes important. Five volts gets you 46 dB in a
high-beta transistor.
OK, I like big R's in current supplies 'cause of lower
Johnson current noise.

The available Johnson noise power from a resistor is the
same irrespective of the resistance. The path to low noise
design is to mismatch it to the load, so that most of that
noise power is reflected. That may sound like an RF concept,
but it's not. It's valid from DC to daylight.

Jeroen Belleman