Dr Slacker's universal resistor pack

[slacker]

Questions like what resistor values should I stock up on? or should I buy this or that resistor multipack? seem to crop up from time to time so I've come up with something that might be useful for people.
Basically you take a small number of commonly used resistor values and then combine them in pairs, either in series or parallel to give a much larger range of values. The idea being that you have to stock up on a small number of resistors allowing you to get the price breaks for buying in bulk.
This is only a first attempt but using 12 different common values of 1% metal film resistor I've got most of the E24 resistor series from 47R up to 4M7 mostly within a 5% tolerance, which should be good enough for most stompboxes.

Here's the list in pdf format fakeresistorchart.pdf this shows the values used and the resistances obtained.

Obviously the downside is that your guts won't look quite as neat if you're having to use a lot of pairs. I also don't how easy it is to combine them in parallel on PCBs, on vero and presumably perf you can usually stick 2 resistor leads in one hole so it shouldn't be too much of a problem. Series should be simple enough whatever you use.

This might also be useful where you've got a good stock of resistors but want the occasional odd value.

Be interested to hear what people think of the idea

[doc_drop]

I add up resisters all the time to get to different values. I have done this on perf and vero. All you do is twist the leads together. If they are in series, you twist one lead from each together and trim it. Then you insert the free lead from each end. For parallel, I do the same thing, but I twist the leads at both ends together, and then cut one of them so I only have to inset one lead in the hole. They can be mounted standing up or laying down like this. I don't solder the connection until the resistors are on the board.

I guess I started doing it like that since I am cheap, and I wanted to only use the resistors that came with a Futurlec value pack. For that matter I also combine caps on occasion. I have never had a problem getting circuits to work as long as I can get a close value.

[slacker]

I guess I started doing it like that since I am cheap, and I wanted to only use the resistors that came with a Futurlec value pack.

That's why I started doing it as well, to use up all the "odd" resistor values from a value pack.

[svstee]

Don't forget that caps are the opposite of resistors in terms of series parallel. easy to make a mistake if you not being careful. Not like I know that firsthand or anything...

[doc_drop]

Yeah, I never made that mistake...especially before I started checking them with the DMM to be safe!