A typical audio amplifier includes two amplifier subsystems, the voltage controlled amplifier (VCA) and the power amplifier (PA). Can the two amplifier subsystems be replaced by one subsystem which can both amplify voltage gain and current gain?

Thanks a lot.

 

A VCA is basically an electronic volume control.

A PA typically amps both V and I to the speakers.

Yes, one can include circuits for both in a design.

Regards, Dana.

 

A VCA is basically an electronic volume control.

A PA typically amps both V and I to the speakers.

Yes, one can include circuits for both in a design.

Regards, Dana.

Hi Dana,

Thanks for the reply
There is still something I would like to clarify:
The VCA I am using has Class AB topologies with Class A circuits. It means that there are switching transistors in the circuit. I've read about switching loss, so I'm wondering if I directly amply current gain at VCA stage, will there be more switching loss(due to leakage current I suppose) and thus less economical?

 

The VCA I am using has Class AB topologies with Class A circuits.

That does not imply switching transistors. A single class A stage typically one
transistor in stage operated in linear fashion.

AB typically 3 transistors, all operated in linear region.

So I am not sure if I have answered question.....

Regards, Dana.

 

Hi

 

That does not imply switching transistors. A single class A stage typically one
transistor in stage operated in linear fashion.

AB typically 3 transistors, all operated in linear region.

So I am not sure if I have answered question.....

Regards, Dana.

Hi Dana,


This is the IC I'm using. Could you please tell me how does Vc input adjust the gain? And when the IC is working under a higher current environment, considering the efficiency of VCA, will the energy wasted be more?

Thanks.

 

Page 10 of datasheet discusses how G control works.

http://www.analog.com/media/en/technical-documentation/data-sheets/SSM2018.pdf


Regards, Dana.

 

noted with

Page 10 of datasheet discusses how G control works.

http://www.analog.com/media/en/technical-documentation/data-sheets/SSM2018.pdf


Regards, Dana.

noted with thanks