Don't get an inverting sinus.

[unitt]

Hi
.
Sorry I can't follow you.

 

[LvW]

Hi
Sorry I can't follow you.

Are you referring to my last posting?
If you have 4 identical sections - each with a damping factor of 1/SQRT(2) - you need active gain stages with a total gain of "4" in order to have a loop gain of 4*0.25=1. OK?

 

[unitt]

Hi
After read and reread the post I get finally what I want, an inverted and non-inverted sine wave.
So thanks to anyone for ther reaction and advice.
thank you for your patient

 

[atferrari]

Hi
After read and reread the post I get finally what I want, an inverted and non-inverted sine wave.
So thanks to anyone for ther reaction and advice.
thank you for your patient

As far as I recall a Bubba oscillator does not give such a jagged sine. Why yours?

 

[Audioguru]

As far as I recall a Bubba oscillator does not give such a jagged sine. Why yours?

The photo in the first reply in this thread also shows the jagged edges. Maybe his opamps are oscillating at a high frequency, maybe there is another high frequency circuit nearby or maybe there is an AM radio station nearby.

 

[unitt]

Hi Audioguru
Your Question about a jagged sine, I really don't know.
Remember, the scope is a simpel usb device, I can see the wave, and the shape give me
a direction right or false, good or bad.
One thing is sure, the device have help me to the solusion.

The opamp, the LME49740, can be a limited factor, but I don't know how to find a better one.

 

[Audioguru]

I guess the jagged edges are produced by your simple USB 'scope.