Postive and Negative Feedback in phasors

[walters]

1.) What is Positive Feedback?


2.) What is Negative Feedback?


3.) how do i hook up a Positive Feedback in a phasor?


4.) how do i hook up a Negative feedback in a phasor?


5.) and What Feedback is it when u take the output of the
     effect pedal and put it to the input to make it oscillate
     is that Postive or Negative Feedback?

[R.G.]

Walters, can you tell us how much electronics background you have before signing on here today?

Your questions indicate either a need for some basic electronics understanding or an unfamiliarity with English, or both. I do not mean those as insults, just observations.

I'm thinking we can do more for you by recommending electronics basics that typing in an electronics education out of order as you think up the questions.

Again, I am not intending to be insulting, just trying to help in a way that I think will be faster for you.

[walters]

1.) Ok there is Two different kind of Positive Feedback
                          a.) internal Positive feedback
                          b.) External Positive Feedback


2.) The External Positive Feedback
              a.) take the output jack signal and put it in the input jack
             b.) Closed feedback loop its called
           c.) loop gain of One will cause it to have Sutaining oscillation
         d.) most pedals feedback like this has a waveform

3.) a Distortion closed feedback loop Waveform is "?"
             a.) is it a Sinusoidal oscillator?
             b.) or it is a Nonsinusoidal oscillator?
        c.) What is the Frequency of the Distortion Closed loop Oscillator?

4.) a Phasor Closed feedback loop Waveform ?
            a.) is it a Sinusoidal oscillator?
            b.) is it a Nonsinusoidal oscillator?
       c.) what is the Frequency of the Phasor Closed loop Oscillator?


5.) a Flanger Closed Feedback Loop Waveform?
           a.) is it a Sinusoidal Oscillator?
           b.) is it a Nonsinusoidal oscillator?
      c.) what is the Frequency of the Flanger Closed loop Oscillator?


6.) a Chorus Closed feedback loop waveform?
           a.) is it a Sinusoidal Oscillator?
           b.) is it a Nonsinusoidal Oscillator?
       c.) what is the Frequency of the Chorus Closed loop Oscillator

[mikeb]

Voice your queries with respect to a particular pedal / circuit and I'd be glad to help.

You do know what a guitar pedal is, don't you? I'm just wondering ... and am also wondering what amp and guitar (or bass or instrument) use you to play with ....

MIke

[DiyFreaque]

1.) Ok there is Two different kind of Positive Feedback
a.) internal Positive feedback
b.) External Positive Feedback

I s'pose.

2.) The External Positive Feedback
a.) take the output jack signal and put it in the input jack
b.) Closed feedback loop its called
c.) loop gain of One will cause it to have Sutaining oscillation
d.) most pedals feedback like this has a waveform

You might consider that the output of some devices is inverted.  In that case, you wouldn't have positive feedback.

3.) a Distortion closed feedback loop Waveform is "?"
a.) is it a Sinusoidal oscillator?
b.) or it is a Nonsinusoidal oscillator?
c.) What is the Frequency of the Distortion Closed loop Oscillator?

Haven't looked at it on an oscilloscope, haven't even tried it, but I'll go out on a limb and say that one would think that the purpose of a distortion box is to distort a waveform.  Sinusoidal doesn't come to mind when one speaks of intended distortion.

Frequency?  Depends on the circuit, particularly any RC combination that comes into play with this setup.  Any color you choose.....

4.) a Phasor Closed feedback loop Waveform ?
a.) is it a Sinusoidal oscillator?
b.) is it a Nonsinusoidal oscillator?
c.) what is the Frequency of the Phasor Closed loop Oscillator?

I've gotten some very pure sinusoidal waveforms with phaseshifters.  Haven't done it in a long time, didn't have a scope at the time, but sure sounded sinusoidal.  

Frequency?  Same, name yer poison.

5.) a Flanger Closed Feedback Loop Waveform?
a.) is it a Sinusoidal Oscillator?
b.) is it a Nonsinusoidal oscillator?
c.) what is the Frequency of the Flanger Closed loop Oscillator?

Waveform can be quite complex, depends on a lot of things - delay time, etc. so forth and so on.  

Frequency?  Most stompboxes boxes usually have at least one control.....

6.) a Chorus Closed feedback loop waveform?
a.) is it a Sinusoidal Oscillator?
b.) is it a Nonsinusoidal Oscillator?
c.) what is the Frequency of the Chorus Closed loop Oscillator

See flanger.

I'm curious, why the question?  Are you looking to build an oscillator or wanting to incorporate oscillation into the effects you build?

The best advice I can give you is to build, man, build.  Start off with a distortion unit and try it out.  Then build a few more.  

After you're done with the distortion, move up to a phase shifter - generally there's a bit more complexity to a phase shifter, because now you're working either with an LFO or voltage control of some sort to dynamically alter the phase of the incoming signal.  Build a few of those, get your chops down and....

Build a chorus.  Now you're into not only LFO's, but high frequency clocks and the glorious agony of working with BBD's.  And companding, if you want something really quiet.

After that, building your flanger will be like falling off a log.

When you're done, get an oscilloscope, plug the outputs into the inputs and have a ball.  And post your results!

Nothing teaches like rolling up your shirtsleeves and breathing solder fumes.  'Course, I'd recommend breadboarding everything before you build.  I never, never build anything without breadboarding it and studying it completely first.  But, that's just me......

Cheerio,
Scott

[walters]

1.) Yes i do want to incorporate oscillation into the effects


2.) what i really want to do if make multiple Send and Return jacks
    at different points in the circuit to Create different oscillations
    or Regenerations ?

3.) what is the difference between Regenerations vs Oscillation?
    they both use feedback but in different ways?
    Oscillation- is Closed loop and the gain is One
    Regeneration- is open loop "?"

4.) An Oscillator- is to convert electrical energy in the form of DC
                        to Electrical energy in the form of AC

5.) How does the Oscillator do that Changes DC and converts it
    into a Form of AC "?"

6.) Run the output jack signal through a Transformer to isolate
    the output and input signals being Feedback on to itself

7.) or run the output jack signal through a EQ pedal then to the
    input jack this is my next talk about

[walters]

1.) Oscillators with RC or LC or Phase shift in the feedback circuit
           a.) Colpitts oscillator-
           b.) Clapp Oscillator-
           c.) Hartley Oscillator-
           d.) Armstrong Oscillator-
           e.) Wien Bridge Oscillator-
           f.) Twin-T  Oscillator-

2.) Oscillator Feedback Conditions?
    List as many Feedback Conditions u know about?

[walters]

1.) If im Oscillating a pedal effect i dont need a guitar or do u just want
    to know in general what guitars Walters uses?

[mikeb]

1.) If im Oscillating a pedal effect i dont need a guitar or do u just want
    to know in general what guitars Walters uses?

Whatever you think is best. I'm trying to decide if you need electronics help, or something a bit more in the professional medical line ....

Mike

[walters]

1.) what u mean by that mike

[mikeb]

1.) what u mean by that mike

What do you think I mean?

Mike

[puretube]

1.) Oscillators with RC or LC or Phase shift in the feedback circuit
           a.) Colpitts oscillator-
           b.) Clapp Oscillator-
           c.) Hartley Oscillator-
           d.) Armstrong Oscillator-
           e.) Wien Bridge Oscillator-
           f.) Twin-T  Oscillator-

2.) Oscillator Feedback Conditions?
    List as many Feedback Conditions u know about?

2.): the first coming to mind would be the Barkhausen "criteria"

google brings a huge amount of interesting reads - a.o.:
http://www.findarticles.com/p/articles/mi_qa3792/is_200201/ai_n9026264
http://www.synergymwave.com/Articles/PDF/ims2001.pdf

[walters]

1.) What is a feedback Condition?
    can someone List the Conditions?


2.) is a Closed feedback Loop running the output signal of the pedal effect
    to the input a Feedback Condition?

3.) is the Feedback internal they call it Regeneration or feedback from the mix/effect stage and run back to the input is this a Condition?

[Toney]

You have asked a gazillion questions, perhaps just go BUILD something.
Read through the REPLYS and THINK about them.

At this rate, you will run out of credibilty so fast, you will just end up with nothing, no answers, no interest.........

[niftydog]

At this rate, you will run out of credibilty so fast, you will just end up with nothing, no answers, no interest.........

he's lost me already and I only became aware of him 20 hours ago.

what's with the numbers? Is he a lawyer or something? Paragraph numbering is a real legal-eagle trait.

walters wrote:
1.) what u mean by that mike


What do you think I mean?

Mike

Touchè Mike!!!  

Walters, many have said this but you don't seem to be paying attention;

just slow down. You are bombarding the board with so many questions, many irrelvant, ill-informed, incomprehensible or wildly off topic and you're gaining nothing from all your effort.

[puretube]

1.) What is a feedback Condition?
    can someone List the Conditions?

feeding s.th. back which bears the same phase as the inputsignal, is a positive feedback;
when the amount you feedback is that much, that it starts to squeal/oscillate, you have met Mr. Barkhausen`s criteria (conditions) for oscillating.
In most cases you can then unplug the guitar, and it`ll keep on squealing.
If it`s a distortion/Fuzz pedal, you`ll get some squarish wave at the output, while you`ll get a more sinusoidal waveform if it`s a "filter" pedal
(which includes phasors (allpass-filters) and flangers/delays/choruses (comb-filters).
This sinewave however might turn into a chopped-off, thus squarishing waveform, when it gets fedback (=re-generated, re-cycled, re-circled...)
again and again, and being clipped by hitting the linear limits of the amplifying devices (transistors/ICs/tubes).

Once you unplugged the guitar, and keep on wanting to make music with the device, it`s time to take a look in the synthesizer`s DIY scene forums.

2.) is a Closed feedback Loop running the output signal of the pedal effect
    to the input a Feedback Condition?

3.) is the Feedback internal they call it Regeneration or feedback from the mix/effect stage and run back to the input is this a Condition?

[walters]

1.) Thanks puretube your a tech in here that is nice and has
     good information
    Thank u so much for reading and taking time out