good, so the datasheet is different, I'm not going crazy

I would too but here I already put "all" op-amps I can get "easy" .. and you suggested lm833 ... I know how nice it is when you can go to local store and get "whatever you like" .. or even better, order online, I lived many years in "normal" countries, but now I live in "messed up country" hence list of available parts is kinda small

I managed to find out that we have a microchip distributor here, and I already got some PIC's from them ... I need to check if they have microchip op-amps and if I can purchase some normal amount (they told me that for some parts min order is 100 pcs) so this might add mcp60(1|2|3|4|6|7|8|9|41) and mcp6S(21|28)

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I recommended National Semi's LM833, not ST Micro's copy of it. Then your circuit powered it from a 24V supply.

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Uncle $crooge

 

I had no idea they are different...

will play with it tomorrow as I will have some time for it .. I got bunch of info from you thanks for that, now I need to solve it - the best way to learn -

thanks, I'll post back when I fix it (or if I discover that I'm too stupid to solve it myself - but with all this info, I hope I'm not that stupid)

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So your using a 40KHz carrier, but I am wondering what your max modulation frequency is.

 

Back in the day, National made many of its parts for the US government based on contracts, and as such, designed and tested the parts to specs specified by the contract. Test time is money and so if spec requirement was only to 10V, then that is what they tested to.
National would then just take the part, remove the MIL-STD part number, and sell it to the public sector. What would be the point in adding test time dollars if not needed? I think the abrupt drop is where no test data is available.

 

good question
no idea, will have to test the circuit as I have no knowledge how to calculate it ... I expect I'll get 6KHz and I believe I do not need more then that..

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National Semi's very old and lousy LM324 and LM358 opamps are spec'd and guaranteed with a supply down to only 3.0V and their very new LM4562 is spec'd and guaranteed with a supply down to 5.0V.

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Uncle $crooge

 

I have solved the problem .. adding few more resistors (trimmers actually) solved it.

I have added a 7660S so now I'm powering the op-amp's with +-5 .. just to be on the safe side as I'm pretty sure audioguru knows his op-amps

In general, the "Heisenberg" point audioguru gave was pretty clear to where my problem lies. The circuit now works with 5V supply alone, but I have added 7660S afterwards so now the total power is 10V....

now I need to build everything else but other parts should not be a problem as it is all digital from here on

audioguru, I thank you again for the "right to the point" explanation.. I'm learning again it feels good

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