No. Lowering the supply voltage does not turn the gain down. It just makes the amplifier start clipping the output.

This sounds reasonable, yet I like to try and make a circuit this way, just to play with the bread board. Is there a way to decrease the input voltage VCC from 100% to 0% using Triacs and/or Thyristors?

I've stumbled upon this page, while looking for more information about converting pots between linear and logarithmic; Tapered Potentiometer, and I don't understand the middle/third field, the one called "Taper (1% - 99%)", what does this value stand for in the circuit?
http://www.diystompboxes.com/analogalchemy/emh/emh.html

 

Is there a way to decrease the input voltage VCC from 100% to 0% using Triacs and/or Thyristors?

Yes, but it's easier to use a Variac.

 

Yes, but it's easier to use a Variac.

I don't really trust electrical equipments that rely heavily on mechanical operation. Using a mechanical pot for my circuit isn't the ideal approach for me. But adding a digital pot would have increased the complexity of the circuit which I wanted to avoid.

So can you provide an example of a circuit that can reduce voltage from 100% to 0%, and completely depending on semiconductors, except for a single mechanical pot such as the one I'm using.

 

I wouldn't bother to design a fool proof method to repeatedly show your theory won't work. You only need one experimental proof that the math was right.

 

I finished the circuit. I tried both linear tapered, and regular log pots, I chose the regular one. I assembled the PCB, and currently in the housing phase.

Thanks for all the help.

 

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