Re: Oscillator Distortion

The FET regulator is a filtered servo with fast cutoff and very slow build up over thousands of cycles. The same is done with other non-linear limiters using exponentially orders of magnitude higher resistance when regulating so the decay rate is slow and low distortion.
Phil I think you had different assumptions for your au contraire opinion on tail currents vs quasi-linear low decay currents when regulated effectively.  I don't see the difference except a non-linear device starts up faster.
On 2024-11-18 3:14 p.m., Phil Hobbs wrote:

 Any oscillator with a nonlinear or bilinear gain control element that has to respond during a cycle has to deal with the distortion caused by that element.  OTAs, JFET variable resistors, PIN diode attenuators, Vactrols, light bulbs, and so on, all have that problem.  Tail current sources can avoid it, because you can make them as stiff as you like by cascoding, and filter the control voltage as well as you like.  (I often use two- or three-pole capacitance multipliers on the supply rails of discrete circuitry, which is a similar idea.)

 Cheers
 Phil Hobbs
 

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Cheers,
Tony Stewart   N. Of Toronto
EE since 1975 practising retirement since 2004