Re: AF Osc AGC alternatives to lamp/thermistor/FET

On Sun, 20 Oct 2024 14:15:19 +0100, piglet <erichpwagner@hotmail.com>
wrote:

Yesterday in the thread "Random thoughts on sinewave oscillators" I
posted a LT Spice wirelist showing amplitude levelling without fet, ntc
thermistor or ptc filament instead using current steering long tail pair
- kinda poor mans multiplier.
>
Here is another alternative, using diode conductance bridge "variolosser".
>
For the full 1960s vibe replace U2 U3 with bjt current sources.

That's still limiting a Wein bridge, essentially a single-element
resonator.

If you do the double-integrator type oscillator, you can do gain
control on the first integrator, and then the second one adds 6
dB/octave harmonic reduction.

I think you can even get 12 dB/octave harmonic reduction if you do the
amplitude limiter right. 12*3 = 36!