Audio Amplifier. Which class should I use?

[Shayaan_Mustafa]

First I have to amplify input around 12V and then add another section to amplify input above 12V. Right.

As we are using TL074 opamp in our discussion up til now. so second section should be same as current section. Should we use cascaded amplifiers?

 

[goldsmith]

No , the answer is most simpler ! ( a guidance ! you can use two transistors ! or perhaps one transistors with inductive coupling !! , but first one will be better ! )

 

[Shayaan_Mustafa]

First I have to amplify input around 12V and then add another section to amplify input above 12V. Right.

As we are using TL074 opamp in our discussion up til now. so second section should be same as current section. Should we use cascaded amplifiers?

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Two transistors means. Darlington pair? Or complementary push pull?

 

[goldsmith]

Not darlington ! a complementary pair . but not at CC arrangement !

 

[Shayaan_Mustafa]

OK. So CE configuration? Because CE configuration gives midrange vaues.

 

[goldsmith]

Seems good choice ! do you know about it ?

 

[Shayaan_Mustafa]

Yes. I know about configurations. But I want to know from you that why did you choose CE? Why not any other configurations? i.e. CC or CB?

Similarly we can use JFET too.

 

[goldsmith]

Shayaan , about CC , arrangement , i thought , you know about it ? it has the unity gain , and in practice lower than unity ! ( i'm talking about voltage gain . )
And CB or perhaps CE , complementary stages are good , however CB has better frequency response !

 

[Shayaan_Mustafa]

So we should CB then.

And yes of course I know CC has unity gain. So CB is better than CE. So I prefer CB. And I think You too.

 

[goldsmith]

Humm ! seems good choice ! so , do you know about it's circuit configuration ? my means is are you familiar with it's schematic ?

 

[Shayaan_Mustafa]

Yes. Here is the link for CB configuration.
https://i1227.photobucket.com/albums/ee430/Shayaan_Mustafa/CommonBasewithvoltagedivider.jpg

 

[Shayaan_Mustafa]

I want to ask somethings.

1) It is first stage i.e. preamplifier stage that we are designing now. Right?

2) Upon completion of this stage will you thoroughly guide me with circuit diagram of this stage?

Thank you goldsmith

 

[goldsmith]

Hi shayaan .
Of course i'm not referring to that circuit . CB complementary means with two transistor !

2) Upon completion of this stage will you thoroughly guide me with circuit diagram of this stage?

Of course i'm here to help !
Best Wishes
Goldsmith

 

[goldsmith]

Dear jetek
Hi
Class A ????? Dissipation across the transistor =2poac . 2*50=100W . what is your reason by this ? would you like to make a heater ?! to cook eggs or cake or .... ?
Best Wishes
Goldsmith

 

[Shayaan_Mustafa]

Dear jetek
Hi
Class A ????? Dissipation across the transistor =2poac . 2*50=100W . what is your reason by this ? would you like to make a heater ?! to cook eggs or cake or .... ?
Best Wishes
Goldsmith

Hahahahahahaha...... You are funny too.. OMG.. You very good person.

Of course i'm not referring to that circuit . CB complementary means with two transistor !

So you mean complementary i.e. one NPN transistor and other is PNP. Right?

 

[Shayaan_Mustafa]

Here is what are you asking for.
Attachment.

But how to modify it as CB configuration?

Conditions for CB configuration:

1) input at emitter.

2) output at collector.

So how to do it?

Help please

Thanks goldsmith

 

[goldsmith]

Hi shayaan
That is in CB arrangement . what do you think about it ? have you access to any simulator program ? if yes , you can convert it to a CB amp and then test it ! and attach the result ! try to earn success .

 

[Shayaan_Mustafa]

Yes I have access to a simulator program. But how to convert it into a CB configuration?
I know about CB that input is at emitter and output is at collector while base is grounded.

But how to do it?

 

[goldsmith]

An example that you'll be able to get the idea with that :
Consider that we have a transistor , and the emitter is grounded via a resistor . and the load is in collector ( between collector and supply ) . and the input is connected to the base ( via a resistor ) what you'll have ? a half wave CE amplifier . with some changes you can convert it to a full wave CE amplifier ( 2 transistors ) .
So , i think you can predict the way to achieve a CB with this example ! can't you ?

 

[Shayaan_Mustafa]

Yes of course I can. But this is not a problem. Problem is how to take output?
For output collector of two transistor should be attached together like in emitter for input. Isn't it?