It sounds like a Canada goose.

 

I tried your ckt as you posted #12, attached simulation file. look at it.. final output wave form(yellow ) is giving square wave.. I adjusted values .. POT vlaues..(1M) for set trailngle GAIN, your ckt working brilliantly, upto opamp C , but opamp D in you ckt not giving sine wave.. ....

Two things -

-The frequency must be 600Hz, +/-3% to optimise the filter response . The final filter is pretty selective (Q=5)

-You are almost certainly overdriving the input to the final filter.The filter section has a gain of 50 at the centre frequency, so you only need a few millivolts of triangle wave from 'opamp C' output.
The phrase 'triangle gain' is not really the right one here! You will need to attenuate the output of the triangle oscillator, rather than provide more gain, to prevent overdriving the filter input. Try replacing RV2 with 100R resistor, and then see what the output of the filter does.

 

It sounds like a Canada goose.

Maybe that's what the project is about ---wildlife sound effects!

 

Two things -

-The frequency must be 600Hz, +/-3% to optimise the filter response . The final filter is pretty selective (Q=5)

-You are almost certainly overdriving the input to the final filter.The filter section has a gain of 50 at the centre frequency, so you only need a few millivolts of triangle wave from 'opamp C' output.
The phrase 'triangle gain' is not really the right one here! You will need to attenuate the output of the triangle oscillator, rather than provide more gain, to prevent overdriving the filter input. Try replacing RV2 with 100R resistor, and then see what the output of the filter does.

Thank you for info... I modified RV2 values as 100R, simulator I am working on.. not is not capable of small step changes.. but I will try it in bread borad. and let you know.. Is there any thing else I have to change .. I mean like C2 values(in my previous post cky or C pot as symboled for OPAMP A feedback CAP) right now I given 10nf..
and ... ~Traingle wave @ output of C is giving more offset voltage(around 2Vto3V for 10k ,20k and 80k) .. and OPAMP D output voltage values(square wave) around +1.5V to -2.5V

 

OK, so you've got your sinewave oscillator. I have not tried any 'simulator' software before myself, but I thought I'd give it a go!
So I tried simulating the circuit with a free program from Texas Instruments called 'Tina' -and got the results attached below.

So now to switch the oscillator off and on. In my original sketch in post #12, I've shown a switch connected to ground the Schmitt Trigger input, via a 10K resistor.
To switch on and off at 50Hz, I would suggest connecting a 50Hz square wave oscillator of some type to switch a general purpose NPN transistor, so that it sinks current, to ground the 10K resistor,and turns 'off' to allow the oscillator to run. As I explained, the relatively gentle start up of the triangle oscillator, coupled with the high 'Q' of the filter should give you the 'smooth' start and finish you're looking for.

 

OK, so you've got your sinewave oscillator. I have not tried any 'simulator' software before myself, but I thought I'd give it a go!
So I tried simulating the circuit with a free program from Texas Instruments called 'Tina' -and got the results attached below.

Hi ROGS,
Thank you for your efforts in this issue.. As I said in my previous posts may be my simulator doesn't running properly. So I decided to use TINA software , to conform my simulator work performance.
Here I am with simution results,, DC output giving almost 2.5V offset voltage..(as my simulation shown..) How can I get ridoff that offset.. still I haven't understande that..
and Your simulation file is AC mode output. I tried in AC mode as well, but when it started waveform voltage levels are 0 to5V and then after some it settling +2.5V to -2.5V.
But I really care about offset voltage,,... please help me in this, issue.
Please find attached copies. Thankyou.. in advance.

 

Two ways to deal with the DC offset.

-Run the system from a +/- DC supply, with the reference (J1) connected to ground, or

-take the output form the filter via a coupling capacitor, to remove any DC offset.

It might also be a good idea to fit a 220R resistor in series with the capacitor, to prevent any tendency for the opamp to oscillate from connection to a reactive load.

 

Two ways to deal with the DC offset.

-Run the system from a +/- DC supply, with the reference (J1) connected to ground, or

-take the output form the filter via a coupling capacitor, to remove any DC offset.

It might also be a good idea to fit a 220R resistor in series with the capacitor, to prevent any tendency for the opamp to oscillate from connection to a reactive load.

Yes, I tried that option, like your post #12 ckt CAP10nf and 51R in series, output is without offset, I given these waveforms to the input of the LM386 opamp gain 20 ckt, output wave forms of LM386 has too much disturption sine wave that means more distrupted sound....
Please find attached file... CH1 is LM386 output wave form(i am using these wave to drive speaker),
CH2 is with offset voltage, CH4 is with out offset voltage..

 

Your TL072 and TL071 opamps have a single 12V positive supply and are biased at +6V so their DC offset voltage is +6V.

Your simulator is not working correctly when set to display AC in the third photo. Then the sinewave should have an average of 0VDC like in the first photo.

I don't see your LM386 amplifier schematic so I don't know why its output is so badly distorted.

 

Reduce the value of R7 to lower the sinewave amplitude, and prevent overdrive of LM386 input. Try 100R or 47R or even 22R.
Remember LM386 has again of 20, so probably only need a few tens of millivolts on it's input.

 

The output waveform of an overdriven LM386 power amp is a square-wave, not the weird wave that is shown.

 

Your TL072 and TL071 opamps have a single 12V positive supply and are biased at +6V so their DC offset voltage is +6V.

Your simulator is not working correctly when set to display AC in the third photo. Then the sinewave should have an average of 0VDC like in the first photo..

Thankyou for INFO.. ..

I don't see your LM386 amplifier schematic so I don't know why its output is so badly distorted.

Here I am , attached LM386 datasheet(PAGE 5) or seperate file attached . Almost same values, I used.

I crossverified with function generator sine wavewith same LM386ckt , distortion is very less compare to designed ckt.
I attached waveforms with and without load(4ohms).

 

Reduce the value of R7 to lower the sinewave amplitude, and prevent overdrive of LM386 input. Try 100R or 47R or even 22R.
Remember LM386 has again of 20, so probably only need a few tens of millivolts on it's input.

Okay,... I tried with 51R, bit better, but still distortion as output. So I replaced R2 47K with POT 50K, I am trying. Thankyou for everything..we are nearly there I think.. without distortions....

 

Your LM386 amplifier is missing a very important supply bypass capacitor mounted very close to the IC. It can be 10uF to 470uF.

The yellow trace in your second photo has a very distorted output but no distortion is shown in the third photo. You should not see distortion at the output of an LM386 amplifier with a load.

 

Hello Everyone,
Thank you each and every one especially ROGS and AUDIOGURU.

I tested ckt in bread borad with TL071&2 series opamp(it arraived latley..), it is working brilliantly....proper sine and my speaker sounding good, except one spike at start... .. I attached file with and without load. I am happy man.... Thankyou all about ckts forum... I learned things with in a short time.. by research on components..ckts.. (ROGS ur star.. in this..)

I am plannig to extend(continue) this project.. with all your help..
I want to make a ckt with one base frequency.. with harmonics(f,1f,2f,3f,4f.......) I read .. different harmonics makes sound ryhtemic or smoother.....How can proceed from this...help me.... I want to build ckt.....

 

Output of A opamp connected to 10k res, insted of Output B opamp.

 

Even harmonics cause a tone to sound something like a violin.
Odd harmonics cause a tone to sound like a buzzer.

 

Even harmonics cause a tone to sound something like a violin.
Odd harmonics cause a tone to sound like a buzzer.

Thanks for info...
How can I generate these harmonics(even or odd or both).... any source to genrate different types of harmonics.. from sine wave oscillator.. or any other method...

 

Even harmonics are caused when a transistor or opamp clips the positive or the negative of a waveform.
Odd harmonics are caused when a transistor or opamp is over-driven so it clips both the positive and the negative of a waveform.

The harmonics are distortion when the input is audio or a sine-wave.

 

Even harmonics are caused when a transistor or opamp clips the positive or the negative of a waveform.
Odd harmonics are caused when a transistor or opamp is over-driven so it clips both the positive and the negative of a waveform.

The harmonics are distortion when the input is audio or a sine-wave.

Okey .... is there any way to test these.. harmonics...I mean... even or odd.. harmonics..I am generating 600Hz audio signal.. , as you said... Transistor or OPAMP producing harmonics.. is there any way to find out.. harmonics frequency.. or can I limit the harmonics.. to particular number..(or can I count..).........!