Where can I purchase a w25k pot?

[Causefarley]

Anybody know where to get these?

 

[Barry]

stompboxparts.com carries a 20K W taper, probably as close as you get

 

[Causefarley]

thank you!

stompboxparts.com carries a 20K W taper, probably as close as you get

 

[Barry]

You could also use a 50K pot and solder a 50K resistor across it to get 25k

 

[fig]

You could also use a 50K pot and solder a 50K resistor across it to get 25k

A homegrown pot is the best. I started buying only 1MΩ and reducing. Makes ordering MUCH easier.

 

[music6000]

20K OHM W-Taper W20K Tone Control Potentiometer PCB Mount Round Shaft Dia: 6.35mm

ALPHA - Get It Fast - Same Day Shipping

www.taydaelectronics.com

 

[finebyfine]

A homegrown pot is the best. I started buying only 1MΩ and reducing. Makes ordering MUCH easier.

Just to make sure I'm getting it right b/c it sounds genius: doing that w/ 1MΩ is just calculating the missing parallel resistor value between 1MΩ and the target pot resistance right and then connecting it to pin 1 and pin 3?

edit: well I guess any value but man the math is easy for 1mΩ

 

[fig]

Just to make sure I'm getting it right b/c it sounds genius: doing that w/ 1MΩ is just calculating the missing parallel resistor value between 1MΩ and the target pot resistance right and then connecting it to pin 1 and pin 3?

edit: well I guess any value but man the math is easy for 1mΩ

Right. I use 1M because they are typically the highest values used. The resulting resistance will always be a bit lower than the lower value resistor used (except when 2 of the same value are used).

 

[finebyfine]

Right. I use 1M because they are typically the highest values used. The resulting resistance will always be a bit lower than the lower value resistor used (except when 2 of the same value are used).

 

[fig]

Google "parallel resistance calculator".

 

[finebyfine]

Google "parallel resistance calculator".

One of the few concepts I remember from high school physics sections on electricity

 

[Chuck D. Bones]

A homegrown pot is the best. I started buying only 1MΩ and reducing. Makes ordering MUCH easier.

HA HA HA HA HA HA HA

 

[Chuck D. Bones]

You could also use a 50K pot and solder a 50K resistor across it to get 25k

Bad idea. It messes up the taper. Pedals that use W taper usually need the W taper.

 

[fig]

Bad idea. It messes up the taper. Pedals that use W taper usually need the W taper.

Isn't the taper decided by the thickness of the carbon layer at the position of the wiper?

( the same way linear and normal / reverse taper function )

 

[Chuck D. Bones]

Yes, for a bare pot. Adding resistors in series and/or parallel changes all that. You have to look at the bigger picture and consider how the pot's impedance varies with rotation and how that affects the rest of the circuit.

 

[music6000]

Unless your Resistors have a taper, you can't recreate number 5 ''W'' taper!

 

[fig]

Yes, for a bare pot. Adding resistors in series and/or parallel changes all that. You have to look at the bigger picture and consider how the pot's impedance varies with rotation and how that affects the rest of the circuit.

Does parallel resistance have a different effect on a circuit than linear resistance?

 

[fig]

Unless your Resistors have a taper, you can't recreate number 5 ''W'' taper!

View attachment 11917

As I understand it, the taper is determined by the thickness of the carbon trail along the path of the wiper. The thicker (wider) the larger % of the whole is seen durinng rotation, and visa-versa.

 

[fig]

btw, I appreciate the time you both are taking. I feel a learning moment coming my way.

 

[music6000]

As I understand it, the taper is determined by the thickness of the carbon trail along the path of the wiper. The thicker (wider) the larger % of the whole is seen durinng rotation, and visa-versa.

How is a Resistor going to change the thickness of the carbon trail along the path of the W wiper?
You can get close with Potentiometers that start out with the Same taper!