# B500k to B1M



## chongmagic (May 26, 2019)

Can I add a 500k resistor to a B500k to make it a B1M pot?


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## chongmagic (May 26, 2019)

chongmagic said:


> Can I add a 500k resistor to a B500k to make it a B1M pot?


I need a B1M for the Stockade but only have a B500K.


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## K Pedals (May 26, 2019)

Parallel Resistance Calculator - Electrical Engineering & Electronics Tools
					

Calculate the total resistance of resistors in parallel with ease!




					www.allaboutcircuits.com


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## K Pedals (May 26, 2019)

I only know how to lower the resistance I’m not sure how to raise it...


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## K Pedals (May 26, 2019)

chongmagic said:


> I need a B1M for the Stockade but only have a B500K.


If you put it parallel it’ll give you 250k


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## chongmagic (May 26, 2019)

Yeah I guess I will have to wait until the B1M pot comes in. GRRRRRRR.


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## K Pedals (May 26, 2019)

chongmagic said:


> Yeah I guess I will have to wait until the B1M pot comes in. GRRRRRRR.


Man what I started doing was ordering tons of bigger pots cause you can always make them smaller... so I just bought a lot of A1M’s and B1M’s... the reason I started doing it was my 100k’s which seem to be the most common were measuring like in the 80’s and 90’s so I started buying 500k’s and converting them so I could get exactly 100k or a little over..


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## Robert (May 26, 2019)

If you put it in series you'll have a pot that sweeps from 500K - 1M.    

This would be okay if you knew you'd _always_ want Gain B to be higher than the maximum setting of Gain A.... but realistically you'll probably be happier if you wait for the 1M pot.

Let me look and see if I have a B1M, I'll be shipping an order to you Tuesday anyway.  ☺


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## chongmagic (May 26, 2019)

Robert said:


> If you put it in series you'll have a pot that sweeps from 500K - 1M.
> 
> This would be okay if you knew you'd _always_ want Gain B to be higher than the maximum setting of Gain A.... but realistically you'll probably be happier if you wait for the 1M pot.
> 
> Let me look and see if I have a B1M, I'll be shipping an order to you Tuesday anyway.  ☺


That would be awesome! I will just wait.


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## Robert (May 27, 2019)

chongmagic said:


> That would be awesome! I will just wait.



Yep, I have one.  I'll send it over.


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## chongmagic (May 27, 2019)

Robert said:


> Yep, I have one.  I'll send it over.


Thank you so much!


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## Chuck D. Bones (May 27, 2019)

Every time I order pots, I order extras.  Sometime I even get lucky and have spares of the ones I need.  Pots are so cheap and sometimes I'm padding an order just so the shipping cost is less than half the cost of the merchandise.  OK, enough rambling, time for a beer.


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## SteveScott (Aug 28, 2019)

K Pedals said:


> If you put it parallel it’ll give you 250k


K Pedals, could you please explain how to wire that up to reduce the resistance of a pot?


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## K Pedals (Aug 28, 2019)

SteveScott said:


> K Pedals, could you please explain how to wire that up to reduce the resistance of a pot?


Sure...
You just wire a resistor in parallel... a leg to each outside lug of the pot... 
Here’s a calculator








						Parallel Resistance Calculator - Electrical Engineering & Electronics Tools
					

Calculate the total resistance of resistors in parallel with ease!




					www.allaboutcircuits.com


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## SteveScott (Aug 28, 2019)

K Pedals said:


> Sure...
> You just wire a resistor in parallel... a leg to each outside lug of the pot...
> Here’s a calculator
> 
> ...


Thank you!


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## K Pedals (Aug 28, 2019)

SteveScott said:


> Thank you!


No problem...


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## Jovi Bon Kenobi (Aug 28, 2019)

That's a handy calculator, thanks! I'll bookmark it. I had to do that with the super hard to find C100k dual gang pot for the photon vibe.


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## Chuck D. Bones (Aug 28, 2019)

This method of paralleling a pot works if you are using the pot as a 2-terminal device, for instance the GAIN pots on the Stockade.  Keep in mind that adding a parallel resistor will change the pot's taper.  Let's use the Stockade example.  We have a B1M pot and want a B500K pot for GAIN_A.  You put a 1M resistor in parallel with a B1M pot.  At the lower end of the gain range, the pot resistance is small compared to the parallel resistor, so the pot's linear taper is essentially unchanged.  By the time we get to 5, the pot's resistance is 500K and the parallel resistor is 1M, so the total resistance is... Let's not all raise out hands at once... 333K.  Which is 2/3 of the 500K total resistance.  In other words, the first half of the pot's rotation has covered 2/3 of the resistance, leaving the second half of rotation for the other 1/3.  As you continue to rotate the pot clockwise, it becomes less and less sensitive to rotation.  The last 10% of rotation takes the pot's resistance from 900K to 1M, but it takes the total resistance from 474K to 500K, a 5% change in ressistance.  This might actually be advantageous if you want to pot to act like it has a mild reverse audio taper.  It will be a little easier to dial in the higher end of the gain range, at the expense of the lower end of the range.  Just don't let it get out of hand, trying to make a 50K pot out of a 1M pot by putting a 53K in parallel won't work out too well.


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