Replacing the standard pot - does the resistance matter?

loz_the_guru

New member
Hi all,

I'm replacing the standard pot and have two options - a Valab stepped/laddered with a 100k resistance, or an Alps black beauty (second hand) at 20k.

I know the standard pot resistance is 20k - the question I have is does it matter if I change this? I need to add 33k/75k resistors to the pot at the same time too, if this is relevant.
 
The standard attenuator has 100k ohm resistance to ground. Get a 100k ohm replacement pot.
If you add the 33/75k resistors to a 20k pot the voltage devision will be different and the padding won't work as intended.
Padding of the volume pot will work with the 100k pot.

IME the Valab is a good pot.

I recently used a DACT type pot with good results in another build. It's really small (convenient for those that need the space) and will work very well in a crack.

https://www.ebay.com/itm/DACT-Type-SMD-Stepped-Attenuator-21-step-volume-control/190844814249
 
Tom-s said:
The standard attenuator has 100k ohm resistance to ground. Get a 100k ohm replacement pot.
If you add the 33/75k resistors to a 20k pot the voltage devision will be different and the padding won't work as intended.
Padding of the volume pot will work with the 100k pot.

IME the Valab is a good pot.

I recently used a DACT type pot with good results in another build. It's really small (convenient for those that need the space) and will work very well in a crack.

https://www.ebay.com/itm/DACT-Type-SMD-Stepped-Attenuator-21-step-volume-control/190844814249

Thanks for the reply Tom-s, very useful and glad I included the info RE 75/33 resistors too.

I've heard good things about those DACT pots before so definitely interested in trying one out - in your opinion is it an audible difference in quality over the stock pot? Also, did you need to enlarge the whole in the base plate?

Thanks!
 
Can't answer your questions as i didn't build it into a Bottlehead amp.

But! It is balanced from low levels. So yes, since i listen with low levels, for me it is an upgrade over a slider pot.
 
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