Noob question: Are all potis and capacitors the same (quality)?

Hey folks,

sorry, I have a stupid question again... I have no experience with electronics, but I can follow a wiring diagram :-)
So my new kit will come sans any hardware/electronics and I'd like to wire it up myself and not use anything pre soldered/finished.

Now, if I'd want to use the typical A500k + B500k pots, there is still a huge amount of different pots at different price points. How do these differ? I'm aware there are push pull potis or long potis, and also that they have different values (like 50k, 250k etc.), but are all A500k potis the same? Where would be the practical difference between, say, Switchcraft or Allparts potis and super cheap ones from China if they look identical? Do these affect the tone itself other than the intended use?

Also, for the capacitors.. Where is the difference between the cheap small green ones and the big orange ones (that anybody seems to want) if they have the same "value" (like 0.0022, no idea what they precise naming is here)?

And, at last, does the thickness of the wire/cable a thing to care for? I have a lot of very thin wire for fine electronics (it's actually my husband's...) but I'm not sure if I should use a thicker gauge?

Thanks for helping an idiot out =)

Its a subject you'll hear a lot of opinions on, but rather less firm evidence.
The practical difference between expensive and cheap pots might be how long they last, or it could be just the name. I find it very hard to believe that tone is noticeably affected, at least not to my ears. I'd be particularly concerned about quality of switches, I've had a number fail on me over the years.

I've never been convinced that capacitors can be very different, but it may be some folk have much more sensitive ears.

Don't forget the actual pickups are made of hair thin wire, so its probably hard for the thickness of internal wiring to make much difference, especially as its over very short distances.

Cap material is basically irrelevant. There are a couple good YouTube videos I could link when I get home that demonstrate different cap materials and values in the same guitar. Values make a big difference of course, higher values roll off more highs.

The main thing with pots are different shaft sizes. For guitar kits you most likely need import pots (metric), or need to drill bigger holes for CTS/Bourns pots (imperial). They also take different knobs so you need to be aware of that.

The problem with cheaper pots is going to be build quality and not tone. Durability, how smooth they turn, things like that.

22awg is a good choice for wire, give or take a little.


Here's the video. It's part 2 with values, part 1 has the different types of caps.

http://youtube.com/watch?v=rR4maqK_IhQ

The beginning of the video is a pretty good explanation of how the caps work with pots to make the tone circuit, and the last demonstration (11 step sweep) is the best demonstration of values.

I have nothing to add that hasn't been said, but I chuckle when I hear/read about people paying ridiculous prices for NOS orange drop caps, bumble bee or paper in oil caps and the like. A 25¢ ceramic or mylar is going to do the same thing.

It's one thing if you're restoring a vintage instrument and want to be period correct, but for modern guitars, there's no extra mojo in getting expensive ones.

Yup, particularly tone caps that are just shunting some high freq signal to ground.
The ones that are used as coupling caps in between stages in an amp are more likely to have some influence as they have the signal passing through them.

Always love the education on this forum :)

Sent from my Pixel 4 using Tapatalk

Different capacitor materials have different frequency passing characteristics, even at audio frequencies. At audio frequencies, in all of the types you are likely to use in a guitar/bass, the equivalent impedance to lower frequencies is higher than for higher frequencies, so there will be some low frequency attenuation of the signal passing through them. And each type of material used in the construction has a different slope, so some will roll-off relatively more low frequencies than others.

So for capacitors in the actual signal flow, the type of capacitor can make a difference. But in a guitar tone circuit, where the capacitor is out of the main signal flow, the effects of the material used are far outweighed by the resistance of the tone pot e.g. a capacitor may have a 10 ohm resistance at 20hz, but a 1 ohm resistance at 10kHz. But add that to the tone pot resistance when set fully up at 10, and even with a 250k pot, you simply won't hear the 0.003% difference in resistance has between 10kHz going through 250,001 ohms and 20Hz going through 250,010 ohms down to ground.

As the tone pot is turned down from 10 towards 1, the percentage contribution of the capacitor resistance increases, until at almost at 1 (no pot resistance) the capacitor's frequency-related resistance finally becomes significant. But by that time, the frequency roll-off of the main signal is complete, and you are only left with the very lowest frequencies passing through. If you like a very muddy sound, then you may get some slight variations in the mud by trying different capacitor types, but the differences will be very small ( and you'll get more variation using your amp's tone controls. Unless you set up a test circuit to switch between different capacitor types, you'd need to record the sounds to A/B them, otherwise you simply wouldn't be able to remember the very, very small tone differences you get.

Otherwise the differences are in tolerance ratings and stability with temperature and time. Very cheap capacitors could have the widest allowable tolerance of -20% to +80%. So if you use a 0.022uF -20/+80% tolerance capacitor, you could be getting anywhere between 0.0176uF and 0.039uF. It's still more likely to be in the middle of those values, but generally a higher value.

A 0.047uF capacitor with the same tolerance rating could be between 0.0376uF and 0.0846uF. So its theoretically possible that a 0.022uF at +80% and a 0.047uF as-20% could have the same actual capacitance.

There are different tolerance ratings used for capacitors, which is an alphabetical code suffix on the capacitor's value. If no code is shown, you should assume the worst case of -20%/+80%. J= ±5%, K= ±10%, M=±20% and Z=-20/+80%.

You can of course measure the capacitance of any supplied capacitors with a multimeter with a capacitance function (or a more dedicated LCR meter) to see how close to the nominal value they are. Remember that the bigger the value, the more high-end they will roll off, and the darker the sound will be once the tone pot is started to be used.

So if you want a repeatable tone circuit, (especially if you are a guitar manufacturer and you want guitars of the same model to all sound the same), using capacitors with at least a ±10% rating will help, though ±5% will help even more.

Different capacitor materials are also differently affected by temperature, which can either increase or decrease the capacitance as the temperature changes (material dependant). However, Class1 capacitors, such as Mica or Polyester, are temperature independent. The reality is that we aren't going to use a guitar or bass in extreme temperature conditions, so they will always be played within a relatively narrow band of operating conditions, so you can really ignore any temperature effect.

Almost all capacitor types will lose some capacitance over time. The best lose almost nothing, whilst other types, (especially electrolytics) can lose a significant amount over 20 years. So if you want the guitar/bass to stay a close as possible to the sound when new, then a capacitor with good long-term stability is required, otherwise you''l find the tone control getting brighter over time down at the muddy end of its travel.

The popular Sprague 'orange drop' capacitors are a good price/performance compromise. They have a decent tolerance and they are very stable over time. A lot of the ones offered are ±10% ones, but if you look around you can find the ±5% ones for about the same price. They are also a polyester type, so are temperature neutral. Physically they are a decent size with good stiff legs, so can happily be used to bridge between a volume and tone pot without risk of the leg breaking off at the solder joint through long-term vibration.

You can spend a lot more on new or reproduction paper-in-oil capacitors, but sonically they really won't be any different and they won't be that stable over time. But they will look nice. And sometimes, given that 90% of tone controls will never move off 10, that's what's really important to people.

There is a difference in quality. Whether it is a difference you can hear is up for debate. Better quality switches and jacks are often worth it as they can last longer and keep better contacts for longer, but are they worth 4x, 5x the price is really a question of personal choices. Electronics are always something you can upgrade later, and if a guitar sounds disappointing often upgrading the electronics is the best place to start. It may not be the case anymore, but 15 years ago the only real difference between a US Strat and a Mex Strat was the quality of the electronics. In fact it was common for struggling professional guitarists to sell their $2000 US models, buy $800 Mex ones, get the switches, jacks, pots and caps changed and end up with a comparable guitar and $1000 cash.

I always use the "chicklet" style caps for tone. I have a couple of orange drops and can't tell the difference in sound. Also, I figure if they were good enough for Leo Fender to use at G&L, they are probably fine. I always test them, though, before I put them in to guitar to see how close they are to their nominal value.

I also test the pots before putting them in. There is not much difference between the build quality of the cheapest pots you can find and the normal "guitar" pots from CTS, Bourns or Alpha. However, the quality control is does seem to be pretty different with the no-name pots. If they test OK with a multimeter, however they are generally fine. I tend to use Audio ("A") pots for both volume and tone, but kits tend to come with a linear ("B") pot for tone. Both work, but they roll off treble a little differently.

Of the name brands Alpha's fit Asian control plates, which most kits come with. For CTS or Bourns you may need to enlarge the hole a bit. None of these are not too expensive, so I generally think the name brands are worth getting. The best, are the milspec (military specification) pots that you can get from Mouser or Digi-Key, but they are really expensive. I have never tried them, but if you need pots that will survive a nuclear attack, they are the way to go. I have Bourns, Alphas or CTS in all my builds/mods so far, since I don't expect to survive the attack.

Wire gauge makes no difference at all. Shielding does, but not the wire gauge.

I'm sorry, I need to revive this thread again.

I need a little help understanding what my guitar does, and why.

In my "new" GR-1SF, I have soldered in one of the orange sprague caps, 223j, mainly just because I found it comfortable to solder on compared to these tiny capacitors that were included. As a comparison, in the single cut build I did before, I have soldered in the tiny green capacitors that were included, these are also marked with 223.

Now, when using the tone pot on the GR-1SF, you can actually hear the tone rolling off and getting darker. On the single cut as a comparison, you can barely even notice it. With a bit of fantasy maybe, but it's by no means as prominent as on the other guitar.

Why is this happening? Do these capacitors really differ that much, or can the pot or capacitor be broken? Any way to troubleshoot it?

Thanks!

Nevermind, if you crank up the amp loud enough, you can hear the roll off very well on the single cut, too. It seems to be connected to the volume, I didn't know that *idiotalarm*

They should not differ much. The "J" means +/- 5%. The green "chicklets" a higher tolerance, but it won't be enormous. Both should be pretty close to .022 uf.

Unless the pots are different, my guess is that the difference is in the pickups. If you are not hearing much treble roll off, you probably need a "bigger" cap. Maybe .033 or .047.

A trick I learned from Weirdbits is to allegator clip in a parallel .022 cap to the one you have now. That will give a .044 value, which should sound similar to what a .047 cap sounds like.

On my last couple of builds I put the caps in last for just this reason. It's hard to know what cap value you want until you hear it

Sent from my ONEPLUS A3000 using Tapatalk

That's a cool trick, thank you!

To be really honest, these are the first times I'm able to use the roll off. I had a Squire Strat back when I was a kid and decided the tone knob sounds horrible, so I never touched it again ;-)

Now, with the tube amp and my single cut builds, I discovered the tone knob is actually useful and on my GR-1SF, the tone knob does really nice things :)

The kit capacitors probably have a wider tolerance than the orange drop, so may have a lower capacitance value. You’d really need to remove them to measure them.

But turning the volume down will also normally roll-off some treble, so low volume means that you gave to turn the tone pot down more before you start to hear an effect.

Connecting the tone pot to the volume pot output (rather than the input as is almost standard these days) will generally keep most of the treble present when just turning down the volume. But it makes the tone and volume pots interactive and the tone pot can slso adjust the volume a bit when used.

Or you can add a treble bleed circuit across the input and output of the volume pot, which stops treble loss when turning the volume down, and lets the tone control operate as expected at part-volume. The treble bleed can be just a capacitor, a capacitor and resistor in parallel or a capacitor and resistor in series. The latter is my choice but the series/parallel options are very similar in effect. A capacitor on its own will normally make the sound brighter as the volume is turned down, so a resistor is added to limit this effect.

And if one tone pot is log and the other is linear, then they will respond in different ways. Only fully up or down will they sound the same, but for other identical settings they will sound different. Log will affect the tone more slowly than linear. Linear will roll off the treble a lot more quickly, so is better if you want to make big changes in tone fast and with a small rotation of the knob, whilst log is smoother in operation and easier to make small changes in tone with, but you do need to turn it a long way to get a lot of roll-off.

Hey Simon,
thanks a lot, I always wondered what treble bleed is, but it looks like it's a great idea.
I also guess you could be right and I may have used an A500k in the GR-1SF and I'm pretty sure a B500K in the single cuts. Out with the log pots I guess! :-)

I much prefer log pots for tone controls as I never want that much treble rolled off.

The linear rather than audio ton pots may account for most of the difference if the pups are the same

Sent from my ONEPLUS A3000 using Tapatalk