I don't have the right resistor value. Solution?

[xorophone]

Hello!

Let's say I for example need an 11k Ohm resistor in a project. I haven't got any 11k, only 10k and 1k.

How do you guys deal with this when using circuits designed by someone else? Editing the PCB layout would be really hard if you don't have the project file.
The only thing I can think of is putting two resistors (10k and 1k) in series on a really small board and then solder that board to the 11k resistor pads. I guess that would work, but it would look really bad.

Any other ideas?

[daleykd]

I buy the right values.

Or, I just deal with 10k.

[galaxiex]

If the difference is only 1K like your example, it likely won't matter. Use the 10K and be done with it.
It might be critical in a timing or possibly bias location tho. Look at schematic and decide.....

Or... you could solder 1 lead of each resistor to each of the pads so they are "standing up" and then twist the 2 "free ends" together and solder.
Kind of like making a little tepee shape like so... ^

Or buy the correct values. 

[gtr2]

Just teepee them up in series as suggested or link us to the schematic and we can help you determine if it has to be that particular value.  Likely a 10k will do, but it's hard to say without an example.

Josh

[bamslam69]

Resistors are reasonably cheap, even when you're being overcharged for one.

[midwayfair]

This is useful enough to keep bookmarked if you deal with projects with weird values often:
http://www.qsl.net/in3otd/parallr.html

However, it is both more secure and tidier to use the right resistor value, even if it's a pain in the butt to have to order something special for a project, or you can simply use the closest value because quite honestly there are almost no places in any guitar pedal where the resistor values are actually critical -- the times when they are, like a bias adjustment, a major gain change, or a useful/noticable frequency change -- there is typically a variable resistor involved anyway.

[davent]

Jon i couldn't find/notice the parallel calculator there. This is the reverse parallel calculator i use, enter the target value, the percentage of tolerance and it spits all the parallel pairs. I've always used parallel pairs rather series strings for values i haven't a single unit for.

http://www.sengpielaudio.com/calculator-parallel.htm

dave

[midwayfair]

Jon i couldn't find/notice the parallel calculator there. This is the reverse parallel calculator i use, enter the target value, the percentage of tolerance and it spits all the parallel pairs. I've always used parallel pairs rather series strings for values i haven't a single unit for.

http://www.sengpielaudio.com/calculator-parallel.htm

dave

I'm not sure what you can't find ... You put in the resistor value you need, press the "calculate" button, and it spits out a half dozen common value combinations with tolerances.

[davent]

Okay I see now. I've obstructed vision in one eye and totally glossed over the two vertical parallel lines in the chart. I saw the first line with the  plus sign and looked for a second table for parallel pairs  designated by //.
Thanks Jon
dave

[xorophone]

Thanks everyone for the replies!

In this case the 11k resistor was just an example, so I don't have a schematic to show you.

Buying the exact values is pretty hard here in Sweden. I don't have any stores I can go to if I want to pick up a specific value and you often have to pay for shipping when ordering online, which is of course not nice when you're just ordering a few different values.

I have a basic understanding of the different parts of a schematic though, so I'll probably be able to tell the bias resistors apart from the rest of the circuit. If the bias resistors for some reason are 11k, changing both to for example 10k shouldn't, from my understanding, affect the circuit at all (as long as both of the resistors are the same value.) And if they're different values on the schematic you'd just have to calculate the ratio and use other values.

Thanks for the links too, Jon and Dave. Those will be handy.

[beneharris]

Thanks everyone for the replies!

Buying the exact values is pretty hard here in Sweden. I don't have any stores I can go to if I want to pick up a specific value and you often have to pay for shipping when ordering online, which is of course not nice when you're just ordering a few different values.

You can't exactly just run down the street and grab a resistor or two in the US, either.  I agree with using the closest value.

[davent]

On Stomptown's Harmonic Percolator board, i was able to parallel 1/8w with 1/4w in values i had on hand rather then place orders for the odd values needed. Also had to parallel caps as i was out of those too.

Finished board and a board in progress showing some of the combos.





dave

[stecykmi]

ya that's probably the most reliable way to do it (more so that two in series imho). it needs a bit of a steady hand tho!