Question about Potentiometer / Volume control.

[xXBrunoXx]

Hi, I have a few questions on a simple matter . Most of the amps I've built never used pots for volume control, I used the signal source's volume control ( digital ) for that .
Now using the classic volume control with a pot like this :

would this affect the quality of the signal ? or , change the input impedance based on the pot's location ?. Using a buffer before the pot would help ?.

What about this , would this be a better approach ? besides the output being inverted and not being able to have " zero volume ". would this affect the input impedance as well when pot is turned ?.

What is the best approach for this ? Best way to use potentiometer for volume control ?. ( besides using digital volume control ic's )
- Bruno.

 

[rayma]

Not a good approach.
For a volume control inside the power amp, use a 10k pot (unless used with a tube preamp/source).
Generally no buffer following the pot will be needed for a 10k inside the amp.

 

[xXBrunoXx]

@rayma ok, but, what would be the " no compromise " , best solution ?.

 

[rayma]

Do you want the pot inside the amplifier to be your ONLY volume control?
If not, why do you want or need it at all?

If it is the only volume control, use a 10k (higher if tube source) switched resistor control, with only high quality resistors and switches.
Tubecad has many interesting options. https://glass-ware.stores.turbify.net/atandsise.html

 

[stocktrader200]

Your 2nd schematic goes to zero volume if the pot goes between the output and - pin.