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Can there be a final word on pots?

Zeus_Mutation

Zeus_Mutation

Feb 6, 2010
89
18
#1
Okay, well I'm looking for a definitive answer regarding pots.

I'm an electronics lamen. I've searched and read about pots and wondered if there's a definitive answer regardless of how much we might WANT there to be more to this pots story.

Please educate me.

If potentiometers are simply just a change in resistance, than as long as it's sweep (maybe wrong word choice there) is accurate (250k, 500k, etc.) then there is NO difference in pots? Even if the materials are better and the quality control is better… functioning within that range, they're equally the same?

So, to me, that means no pot offers any tonality differences. True or False?

A crappy cheap mini pot with the same resistance as a fancy pot functions exactly the same. The difference maybe is durability or something, but thats about it. Have I caught on yet?

Granted - If a pot isn't fully 250k or whatever, changing them for one that is… would be the only way your tone could change. Because your getting the full sweep versus only a portion of it as before?

I've read many threads talking about "this pot or that pot" and they do "this and that" comments. To me if its as simple as how accurate the sweep is, theres no magic fairy dust inside ANY of them.

What's the truth?
 
#2
The true is as I see it are as follows:
A. Better materials and Quality Control in Manufacturing lead to greater longevity.
B. There are basically 2 types of potentiometers (pots) Linear Taper and Audio Taper (logarythmic taper to counter the way the ear responds to volume changes.
C. The only thing that will affect the tone to any degree is the value. i.e. 250K load the pickups more than 500K. 250K ohm pots are typically used to counter a single coil's inherent brightness as it will warm the tone up somewhat while 500K are typically used for humbucking style pickups that exibit a slight loss in high end (darker sounding in general but not definative by any means). Less loading allows the pickup to open up.

Please note I said typical and is by no means saying it is a "Black and White" issue but what the individual is looking for in tone with a particular instrument
 
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#4
Longevity comes with its own set of crap to deal with. A pot (usually) will not simply work or fail. There are many degrees of "failure" in between. In other words, as it wears down, it will, in fact, cause scratching. That scratching indicates areas that make better or worse contact. That better or worse contact will change the value in ohms and affect the signal slightly in other ways. So, in my view, a crappy pot on the way out will affect your tone. Never mind that the scratching through a PA is just about the most annoying sound on Earth.

Pots are cheap anyway. Why not just get one made with better materials and be done with it? What are you gonna do with that extra few dollars? Biggie size your Mickey D's combo? ;)
 
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#5
Zeus_Mutation said:
Got it, they make absolutely no difference. Pots of the same value that show that value via a multimeter, by example, are the same always. Longevity being its own debate.

Thanks
Click to expand...
Except For Linear taper and Audio taper. Linear taper has the same rate of change throughout turning of the shaft while audio taper changes slowly at one end then increasing more quickly as you turn it further
 
#6
Research the threads. There are a couple of old threads that analyze different make, model and value of pots. It is rather complicated, especially since some of pots, in order to get an approximation of an audio taper actually have a two-piece wafer with two different linear progressions.

As for me, in playing electric instruments for 40 years this April, I have never had a CTS 250 or 500 kohm audio taper pot fail. I have always had good reliability, feel, and progression from them.
 
#7
Aside from the audio / linear & quality. The functionality is the same. That's where I was going.

They are cheap, and I agree why not put CTS or similar in… but, if they are working and the value is there, changing doesn't do much. I personally like the feel of CTS solids.

We often get filled with unnecessary information on things in general, and when not needed, I like to delete mental files and streamline my brain. lol. That's what this thread helped me do.

Thank you
 
#8
Good job. You're absolutely right. We can perform this thought experiment:

1. Take a high-quality pot of your choice (CTS, Bourns, whatever) rated at 500K. Taper doesn't matter. Turn it until its resistance measures 450K on a multimeter. Install it into a bass without turning the shaft. Record sound samples.

2. Take a total crap bottom-of-the-barrel piece-of-sh!t pot made in the worst factory in the world rated at 500K. Taper doesn't matter. Turn it until its resistance measures 450K on a multimeter. Install it into the same bass using the same circuit and pickups. Record sound samples.

3. Take note of the fact that the tone doesn't change a bit.

(450K chosen to account for the fact that a pot rated at 500K might not be able to actually reach 500K, due to manufacturing tolerances…)
 
#9
ctmullins said:
Good job. You're absolutely right. We can perform this thought experiment:

1. Take a high-quality pot of your choice (CTS, Bourns, whatever) rated at 500K. Taper doesn't matter. Turn it until its resistance measures 450K on a multimeter. Install it into a bass without turning the shaft. Record sound samples.

2. Take a total crap bottom-of-the-barrel piece-of-sh!t pot made in the worst factory in the world rated at 500K. Taper doesn't matter. Turn it until its resistance measures 450K on a multimeter. Install it into the same bass using the same circuit and pickups. Record sound samples.

3. Take note of the fact that the tone doesn't change a bit.

(450K chosen to account for the fact that a pot rated at 500K might not be able to actually reach 500K, due to manufacturing tolerances…)
Click to expand...

And if your plan included never ever turning said pot and leaving it at 450 forever you would have a great point. But if it includes regularly turning the aforementioned pot(s) then give me a good one every time. I will proceed to regularly clean it with Deoxit or some other quality contact cleaner and mine will never scratch and probably never wear out.

But, yes, 450 trick will work beautifully if you then super glue the knobs in place. But if you're going to do that just stick a resistor in there and be done with it. :thumbsup:
 
#10
right; sonically, resistance is resistance, the same measured values will have the same sound.

better pots are more reliable, maybe even feel better to turn.

different tapers will behave differently as you turn them.
 
#12
two fingers said:
And if your plan included never ever turning said pot and leaving it at 450 forever you would have a great point. But if it includes regularly turning the aforementioned pot(s) then give me a good one every time. I will proceed to regularly clean it with Deoxit or some other quality contact cleaner and mine will never scratch and probably never wear out.

But, yes, 450 trick will work beautifully if you then super glue the knobs in place. But if you're going to do that just stick a resistor in there and be done with it. :thumbsup:
Click to expand...

You're combining two different premises, whether intentionally or unintentionally.

The first is (as the OP tried to make) that resistance is resistance within the context of bass electronics, and brand/taper/quality of the pot doesn't have an effect on tone as long as the resistance is sufficient.

The second is the undisputed benefit of a quality pot in terms of tactile feedback and longevity, but not tone.

My thought experiment was aimed squarely at the first, and not the second.
 
#13
ctmullins said:
You're combining two different premises, whether intentionally or unintentionally.

The first is (as the OP tried to make) that resistance is resistance within the context of bass electronics, and brand/taper/quality of the pot doesn't have an effect on tone as long as the resistance is sufficient.

The second is the undisputed benefit of a quality pot in terms of tactile feedback and longevity, but not tone.

My thought experiment was aimed squarely at the first, and not the second.
Click to expand...


Fair enough. My only point is that out of the box and brand new both of you are correct. However, down the road, as they start to wear, the cheaper ones will wear more quickly and (in my view) more harshly. Therefore, they will in fact have an impact on your tone. That is why I was stressing the point about never moving them. If you leave them alone and never turn the knobs, they will always sound the same. But down the road a while, if you use them regularly, they will not.

I was simply injecting time and use (aka wear and tear) into the discussion. They will wear down differently, and at different rates. So initially they will sound the same but later they won't.
 
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#14
There will be no tonal difference if rated values are the same between brands. As others have said, it comes down to build quality and preference for the turning feel. Alpha pots seem to be the most popular pot to use by many pedal and amp builders. I never really liked them in a guitar circuit because the tapers don't seem as consistent. On the Squier basses whose Alpha mini/metric logarithmic pots I've replaced, the sweep of the turn almost always improves by stepping up to a full size CTS or Bourns, meaning the audible signal begins earlier when turning up the volume pot (as opposed to no signal until a approximately a quarter turn, almost behaving as a linear) and the sweep of the tone becomes more gradual. I've even noticed an improvement stepping up to full size Alphas over the minis in this regard. That said, not all pots within the same model/make are created equal and I'll occasionally come across a CTS with a crappy taper. I think it has more to do with the size than the quality in these cases, as I've replaced other mini's that exibited similar behaviour...I just don't like mini's in a passive guitar circuit.

I think as far as robustness of build quality and consistent performance, the CTS EP885 series are my preferred type, followed by Noble, which makes an excellent product on par with the better CTS stuff, but doesn't seem as well known for some reason. For smoothness and speed of turn and consistent quality, I like Bourns. Unfortunately, I see a lot of "cooked" Bourns pots as they seem especially prone to failure as a result of too much heat being applied during soldering. Same thing with the Alps, whose outer casing is very similar to the Bourns and just as vulnerable to heat damage. The CTS and Noble seem to be a bit more durable in this regard.

Tonally, there's no difference IME between ANY pot brands. It all comes down to which ones are testing as rated and performing to spec. There's no mojo to it (check out some guitar forums for a REAL laugh on the matter), but use what works and sounds good, be it Alps or CTS. When the difference in price can be cents, there's no reason not to experiment...unless you're foolish enough to drop $100 on Alessandro matched 250k "mil-spec" pots.
 
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#15
IME, the quality of the soldering job seems to affect tone more than the quality of the pot. I've redone a few botched up jobs (mostly my own) and gotten noticeable improvements in tone.
Also, I tend to run all volume pots at full anyway, negating any effect it may have on tone.
 

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