50K vs 100K POT

[ss1]

Hello ,
i'm a newbie. I just upgraded my pot from alps 100k (radio shack) to 50k alps black pot and I noticed that the sound got louder. Should I switch back to a 100k pot to better control the volume? Curious, how much volume can a 100k vs 50k pot lower by? or can i add a 10k resistor to the 50k pot to lower the volume? any comments?
thanks

 

[Richard C]

The value of the pot if wired correctly shouldn't make any difference to the volume. It's the ratio of the resistances either side of the pot wiper that set the output level not the absolute value of the pot.

 

[Centauri]

If the original pot was logarithmic taper (most likely), and the pot you used to replace it is linear taper, then new pot will be louder at settings below full volume. Log taper varies the volume by increasingly larger amounts to compensate for the way our ears hear volume changes.

Cheers

 

[rabbitz]

If it's a 50k linear, use Rod Elliott's law-faked volume control by adding a 7.5K resistor to ground. See the details at Rod's site.

http://sound.westhost.com/project01.htm

 

[ss1]

thanks everyone for the info that explain the problem. the new pot is good but it's loud.

Do i wired the resistor like this
http://sound.westhost.com/p01-f1.gif

what kind of resistors should i use riken, mills,etc?
thanks again

 

[rabbitz]

Yeah, that's the circuit.

Resistor goes between the output and ground (centre pin to ground). All that is specified is 1% metal film resistors and I'm sure there are benefits from using a higher quality resistor. I think the better the quality the less noise.

 

[ss1]

hello
according to the diagram, i have to wired the resistor before the signal reach the pot?

flow diagram
1)input signal -> 2)resistor -> 3) pots -> 4) output signal (going to amp)

thanks

 

[rabbitz]

I see where you are coming from as the diagram is a bit misleading as the arrows appear to point the opposite way. Reverse the arrow directions and that's the signal direction.

If you look at the pot from the front (shaft pointing towards you), the first connector on the left is #1, centre #2, right #3.

#1 is ground
#2 is output
#3 is input

See this pic: http://sound.westhost.com/pots-f5.jpg

Resistor goes from #2 (output) to ground. This only works for a linear (B) pot and not a log (A) pot. Was a lot easier when a manufacturer included that info in the part number such as AX2 would be a dual gang log pot and a BX2 would be a dual gang linear pot.

Hope this clears it up for you.