Resistors: 1% vs 5% ?

[khm9]

Hi,

I am looking for answers which pedals to build with 1% resistors and which with 5% resistors.

My near future builds are:
-Big Muff triangle
-Fuzz Face NPN
-Deep Blue Delay

For the dirt pedals I thought maybe it's better to use 5% resistors and for the delay pedal 1% resistors?

Which resistors would you choose in my case? and why?

Thanks

[GibsonGM]

I don't think you'll notice a thing with either type      Our circuits aren't THAT critical...

Good thing to wonder about, though!

[chuckd666]

Doesn't really matter for most DIY guitar pedal related things, because the tolerances aren't very strict. I suppose it would depend on the circuit.. just use what you have at hand/what's cheaper!

[khm9]

I don't think you'll notice a thing with either type      Our circuits aren't THAT critical...

Good thing to wonder about, though!

Doesn't really matter for most DIY guitar pedal related things, because the tolerances aren't very strict. I suppose it would depend on the circuit.. just use what you have at hand/what's cheaper!

I thought maybe with 5% resistors used with fuzz for example would sound more 'natural', since I doubt they used 1% back in the day, and 1% for delay pedal more precision?
I don't know it's just a wild guess... 

[bluebunny]

I thought maybe with 5% resistors used with fuzz for example would sound more 'natural', since I doubt they used 1% back in the day, and 1% for delay pedal more precision?
I don't know it's just a wild guess... 

It's not the tolerance of the resistors that makes a fuzz fuzz.  As for "natural"??  I don't believe that fuzz pedals occur naturally.   

(Bottom line: you won't hear any difference.)

[anotherjim]

1% will be metal film rather than carbon =  low noise/higher value stability. You can find 2% in old stuff.

Normally you can freely use metal or carbon. Reserve metal for 100k or higher values, because the noise issue increases with resistance. Fussy audiophile stuff will use 1% metal film for everything regardless.

For vintage "never mind the noise, feel the mojo" go for chunky carbon composition 10 or 20% for the wide & pretty code bands.

It might actually turn out that, this side of the mixing desk, a little noise is no bad thing. The human is not only very good at hearing signal against noise, but could actually enjoy it more that way.

[EBK]

I have a bunch of low value 1% metal film resistors laying around that I haven't found much use for (1-ohm, 1.2-ohm, 1.5-ohm, etc.).  You can mix them in a bucket, and randomly throw some in series with whatever resistors you need if you really want looser tolerances. 

Interesting OT question though: I actually have some 0-ohm resistors too (seriously, it's a thing).  How much current can you safely pass through a 1/4-watt 0-ohm resistor?   

[ashcat_lt]

How much current can you safely pass through a 1/4-watt 0-ohm resistor?

Ummm...   P = 0/(0^2) = 1? 
But then P = 0 * (1/0) = 0, which I think is kind of closer to the truth.  If it's actual 0 ohms, there's no voltage drop, no power dissipated, and other components in the circuit will blow up first.

As I understand it, these are basically jumper wires, but in standard resistor package to make board design and automated population easier.

I thought maybe with 5% resistors used with fuzz for example would sound more 'natural', since I doubt they used 1% back in the day...

If you make a fuss with 5% resistors, it will be harder to predict what it will actually sound like.  The transistors are usually so wildly variable that you've got plenty of randomness already.  If you have one specific fuzz box with 10% tolerances that you want to clone, measure all of the components in it, then use 1% resistors to match those values. 

It might actually turn out that, this side of the mixing desk, a little noise is no bad thing. The human is not only very good at hearing signal against noise, but could actually enjoy it more that way.

I have the stupid idea that some noise going into a non-linear stage is important to getting a more "natual" or "analog" sound.  It has an effect very similar to randomizing the nonlinearity itself so that rather than a smooth curve, it's...well... messy.  Any given instantaneous input voltage will have a slightly different relationship to its output than another, even when those voltages are exactly the same.  And that must have at least a subtle effect on the harmonic content of the output.  Anyway, when I'm working in the "perfectly silent" world of digital audio, I very often end up adding noise one way or another along the way partly because of this weird notion.

But more importantly, I think noise is how you know it's loud. 

[GibsonGM]

I have the stupid idea that some noise going into a non-linear stage is important to getting a more "natual" or "analog" sound.  It has an effect very similar to randomizing the nonlinearity itself so that rather than a smooth curve, it's...well... messy.  Any given instantaneous input voltage will have a slightly different relationship to its output than another, even when those voltages are exactly the same.  And that must have at least a subtle effect on the harmonic content of the output.  Anyway, when I'm working in the "perfectly silent" world of digital audio, I very often end up adding noise one way or another along the way partly because of this weird notion.

But more importantly, I think noise is how you know it's loud. 

This is why even if you measure all of the parameters (C's, R's...Hfe, maybe.....) about a fuzz, you won't get "reproduction" by using 1% resistors.    The internal, dynamic properties of the transistors are probably enough to make matching R's and C's exactly a moot point.  The magic is going to be in how all the components interact, not just a few.  Too bad we really CAN'T  *exactly* match say, Jimi's favorite FF!! 

Maybe you could come close...but 1%?  You're better off just measuring the R's you like in a fuzz and finding some that are close among your junk box parts!       Or use a pot here and there, and pop in close values that you measure, once you've tuned it...


>>>Seems that the power a Zero Ohm resistor can handle would be the same as that of the wire it's made from?  *shrug*

[induction]

Ummm...   P = 0/(0^2) = 1? 

P = 0/(0^2) = 0/0 = undefined 

P = 0 * (1/0) = 0

P = 0 * (1/0) = 0 * infinity = undefined

In any case, P = V^2/R = R*I^2 = I*V, so it's not clear to me what your formulae refer to here.

How much current can you safely pass through a 1/4-watt 0-ohm resistor? 

The correct answer is 'check the datasheet'. 

[GibsonGM]

It cannot have zero resistance.  There is no substance with zero ohms of resistance at room temperature.  Even a small jumper wire has SOME resistance, which is what the zero ohm resistor is....a jumper with a different name   So we can't use "zero" for Ohm's Law.

A tiny thread from a stranded wire may handle perhaps 1A...depending on the gauge, maybe even 4A.  If you have one, measure its resistance...

I like the idea of checking a data sheet, LOL!!! 

[khm9]

I have a question:
why do 0 ohm resistors even exist?
why use a 0 ohm resistor when you can just use a regular jumper wire instead?

[bluebunny]

why do 0 ohm resistors even exist?

these are basically jumper wires, but in standard resistor package to make board design and automated population easier.

[khm9]

why do 0 ohm resistors even exist?

these are basically jumper wires, but in standard resistor package to make board design and automated population easier.

I still do not see the point in using those. They are useless

[bloxstompboxes]

why do 0 ohm resistors even exist?

these are basically jumper wires, but in standard resistor package to make board design and automated population easier.

I still do not see the point in using those. They are useless

In present day smd circuit design where size is critical, a zero ohm resistor is a jumper over a very small trace where a through hole jumper just won't fit or work. Think about multi layer boards. They are anywhere between 2 and probably a dozen layers possible in multilayer pcbs. Through hole components aren't always possible in these layouts. We used 0ohm resistors a lot when I was at Harman. They can be used in our pedals too. handmade jumpers are just easier and more cost effective. 0 ohm through hole resistors might be easier for radial/axial machines to dispense onto boards too.

[Ice-9]

I have a question:
why do 0 ohm resistors even exist?
why use a 0 ohm resistor when you can just use a regular jumper wire instead?

0 Ohm resistors exist and are used a lot in both SMD and through hole pick and place machines, a pick and place machine can fit these a lot easier than trying to fit a wire jumper which would more likely need to be hand placed and soldered. So it is a faster and cheaper to fit a 0 Ohm resistor than have to fit a jumper wire in a production line.

[GibsonGM]

I have a question:
why do 0 ohm resistors even exist?
why use a 0 ohm resistor when you can just use a regular jumper wire instead?

Yes - basically, they are useless to US, here!  They're not even allowed in my parts bins...non-grata and all that...

[ashcat_lt]

Ummm...   P = 0/(0^2) = 1? 

P = 0/(0^2) = 0/0 = undefined 

P = 0 * (1/0) = 0

P = 0 * (1/0) = 0 * infinity = undefined

LOL, yeah, you have to squint, but as R approaches 0...

Edit - actually, I think both expressions head toward 0 because the squared voltage goes toward 0 faster than the resistance upon which it depends. 

In any case, P = V^2/R = R*I^2 = I*V, so it's not clear to me what your formulae refer to here.

Yeah, I put the square term in the wrong place in the first one and the other should have really been 0 * (0/0)....  Remember that V in this case is the drop across the resistor, and as that R approaches 0, that drop also approaches 0.  Then, as that R approaches 0, the current through it for any drop across it approaches infinity.  I suppose IRL, it will be limited by whatever the rest of the circuit.  Either way it works out to where there really isn't much power dissipated in that 0 ohm thing.  Unless it's directly across the power supply, you probably don't have to worry about it until the voltages get way bigger than what we have in a pedal.

[EBK]

Unless it's directly across the power supply...

Sounds like empirical data may be required!  (sorry for hijacking the thread, by the way.   )

[induction]

LOL, yeah, you have to squint...

Yeah, I don't disagree with your conclusions. I was just being pedantic. Everyone needs a hobby.

I avoid taking limits with Ohm's law because it isn't an empirical law, it's a definitional convenience. Long ago in an distant undergraduate lab I plotted V vs I for a variety of resistors and found the curves were quadratic (IIRC), not linear. (Oh the golden memories of youth. Timeless treasures of blah blah blah blah...) Of course, any smooth curve is linear-ish if you look at a small enough part of it.

In any case, I am skeptical of the ability of little wires dressed up like resistors to successfully navigate L'Hospital's Rule or other mathematical niceties, so I generally suggest just looking up the answer in a datasheet.

Of course, this approach has its own set of impediments.