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Help me decipher potentiometer markings

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Newbie level 1
Oct 23, 2009
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Hi, hope some experts out there could help.

I have a guitar which its volume and tone knobs need to be replaced.

I couldn't find the parts with the exact values marked on the existing once. the marking is like the following:


Question 1: what are the definations of the marking? eg.whats the "M" stands for?

Question 2: what is the bottom value (33K) for? as all electronic stores I visited don't have the one like that, and no one could answer what that value is.

Question 3: is it very important to get the exact value one, or it doesn't really matter?

Thank you

Potentiometer codes

If you have a doubt about the value of the pot, just measure it with a multimeter with its probles connected to the extereme ends of the pot. The said Potentiomenter is 250K A. Just ignore rest markings as they may represent some batch numbers or any other terms. But i guess you may not get exact 250K A pots in the market. Just ask for 220K A pot which will be a substitute to the exixiting one.Remember to have same letter A next to 220K markings. Using a pot with anyother aphabet will result in sudden jump or cut in the function controlled by the same as the properties of the pot (LOG/ Linear) differ with the last letter mentioned. Cheers

Potentiometer codes

Hi piew,

I think "M250KΩA 33K" menas for you, that you need a poti with 250K or for ex. in practicum you can apply usually 220KOhm too.

It`s possible, that
M=20% as tolerance and
A means:
these poti has linear characteristic!

Similar as wrote pranam77 too.

33 is usually= number of calendar week of year...
and K can be some other coding; as for actual year or even produtions place etc...
These boths are producer specific coded.

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