Oh yes I have and this is precisely why I categorize these <5nF cap shenanigans as "tone voodoo" because they operate at frequencies that are filtered out at some point in your signal chain anyhow.
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Change a pickup's resonant frequency and tone with a loading capacitor
- Thread starter fermata
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The point where they are filtered out is at the pickup/cable interface itself. A P bass's pickup resonates at about 2 kHz, and rolls off past that - but on that rolloff slope there is significant energy beyond 2 kHz- you do hear that stuff. When people on here are discussing various P or J pickups, most of the differences they are hearing are above 2Khz - pickups are flat below resonance, all the differences are up there. A Jazz goes out further, some actives go well beyond that. Bass amps do have built in eq, but most of them will reproduce stuff to 20kHz, and people are putting tweeters into bass cabinets nowadays that start working at 2 kHz.
You may consider it "tone voodoo", but there is a lot happening up there that matters to your sound, unless you are always playing with your tone rolled off. Do you play Reggae?
The .0047uf cap mentioned was not in the context of a loading capacitor, but a capacitor put in series with a pickup which acts as a simple high-pass filter (that exact value is the same as used in the HPF capacitor permanently wired to the bridge pickup in Rickenbacker 4001 basses).
Loading capacitors on the other hand act in concert with other capacitance in the circuit in an additive way (capacitance both inside the pickup and in the output cable, controls, etc) to create the resonant frequency of the entire passive circuit of the instrument +cable circuit (basically until the point where you hit some buffered input the cable is adding capacitance and lowering the resonant frequency of the instrument), so the resonant frequency of the pickup + loading capacitor is always lower than the resonant frequency of the isolated pickup (and 99% of passive bass pickups have very audible resonant frequencies in the low treble or high-midrange region to begin with).
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5nf is 5000 pF. A lot of guitar cables are made with cable that has on the order of 27F per foot of cable. 5000pF would be a 185 foot cable - are you saying you wouldn't hear the difference that a 185 foot cable (on a passive bass) would make?
No but the treble frequencies you are obsessing about are pretty irrelevant unless you play solo bass concerts or (in your case) record into an oscilloscope.
Even if they are not filtered out at some point by someone or someting (like your bass speaker itself), other instruments will vastly overpower your signal in those frequency regions, making them a mostly theoretical aspect for audiophiles to obsess over and get lost in a rabbit hole...
@sunbeast Seems like people here can't seem to even agree on the definition then. Couple of pages before, it was said that around 5nF is exactly the kind of range for a "loading cap", with values above 10 being "tone cap" values.
I play church gigs - a lot of material where there are breakdown sections - bass, drums playing toms, no guitar - there are lots of places where there is no competition in the upper mids (where this stuff is happening) - "somewhat solo bass" happens a lot more than you think. When I get to playing "clanky" stuff, you wiil hear it even if the guitars are there.
It's still nowhere near fundamentally changing a pickups character.
The frequencies where these tiny caps make an audible difference are so harsh sounding that no sound engineer in their right mind would let them go through unfiltered, meaning your little "loading cap" will be irrelevant to the final sound, at least relatively speaking to the lower frequencies of your signal.
If you had truely transparent monitors or headphones, you would turn your tone knob way below this threshold anyhow.
I am certainly no "overtone hater" but even on my fretless jazz, wide open tone sounds absolutely disgusting and it hurts your ears. That said, if I was only practicing through my bass amp (as opposed to headphones), I probably would have never realized how unimportant those higher treble frequencies actually are to my sound, which is where I think a lot of false conclusions are drawn by people.
The frequencies where these tiny caps make an audible difference are so harsh sounding that no sound engineer in their right mind would let them go through unfiltered, meaning your little "loading cap" will be irrelevant to the final sound, at least relatively speaking to the lower frequencies of your signal.
If you had truely transparent monitors or headphones, you would turn your tone knob way below this threshold anyhow.
I am certainly no "overtone hater" but even on my fretless jazz, wide open tone sounds absolutely disgusting and it hurts your ears. That said, if I was only practicing through my bass amp (as opposed to headphones), I probably would have never realized how unimportant those higher treble frequencies actually are to my sound, which is where I think a lot of false conclusions are drawn by people.
We completely disagree, and will continue to do so. I'm OK with that. Have a nice day.
I mean, does rolling the tone knob down a bit fundamentally change a pickup's character to you?
If so, then we simply define "tonal character" differently.
Anyway, you said you have countless measurements and models archived.
Would gladly see some of those curves.
I think it would help everyone here put some concrete numbers to these pretty wishy-washy descriptions and impressions.
Here's a screenshot of the electrical response of a P bass with different loading capacitors. The blue curve (kinda faint) is with the tone control on that bass off. The biggest loading cap here is about 4 nF.
In an earlier post you admitted to not finding our results with smaller caps. So are you trying to get educated or just arguing? I don't agree with what you are talking about, nor do you seem to understand what the loading cap does. Its not filtering harsh ultra highs as you seem to think. It quite honestly changes the mid or high frequency focus. As you can see in the image previously posted. Admittedly, it can be subtle on some pickups, but there is a definite audible difference and its not the same as using a tone knob. Nor would i replace a tone cap with a smaller value for this purpose. My tone knob is still my tone knob. We arent just removing treble.
ps: i believe audere preamps come with different caps in the smaller values to change the z-mode frequency response.
If you ever put a StingRay into passive, the character in the upper mids and highs completely changes. Capacitors on the preamps circuit board are to blame. So its not just in our heads.
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Interesting read : BuildYourGuitar.com :: The Secrets of Electric Guitar Pickups
I’m curious, how do you define tonal character, and what influences it the most?
Shaping the resonant peak does a lot, but not everything. It starts with strings, setup and technique. Etc… But in the right context with the right player, tweaking the resonant peak can do everything that player needs accomplished at that moment. That’s the power of these little cheap loading caps.
Tweaking the capcitive loading is definitely the most interesting aspect. It's roughly equivalent to a rewind with more or fewer turns or wire, probably as effective as a pickup swap in the majority of cases. More common than you think you will find loading caps when you open the wiring harness of touring musicians instruments, put there by a tech to solve some issue fast and sometimes it stays as a permanent feature.
But pickup makers are very good at convincing people that they posses control of some magical variable that plays a bigger part in the defining the tone. It's not much more than marketing to me.
But pickup makers are very good at convincing people that they posses control of some magical variable that plays a bigger part in the defining the tone. It's not much more than marketing to me.
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I agree 200 percent - I don't think you've gone far enough. When you make detailed measurements of different pickups, a lot of models are identical in terms of the magnetic circuit, but are variations in windings. The only difference between models in terms of performance is their electrical characteristics. More or less turns isn't "roughly equivalent" to a loading change - it's actually identical in terms of the frequency response changes you get.
I'd also argue it's more effective than a pickup swap - with a pickup swap, unless you've measured the pickup and know its impedance over frequency, you don't know if the swap will push the response in the direction you want - with a capacitor change, you know which way it's going. Also, if it's not quite right, with a load change, you have recourse to fine tune it - if your only approach to find the sound you want is pickup swapping, it's pretty much a crap shoot as to what you'll get, with no out if it isn't what you were hoping for.
All very good points. I think we are firmly outside the Matrix of pickup marketing.
The stuff I think makes a objective difference beyond LCR parameters (or harder to equalize with external components) is ironically under-marketed:
Sensing width of coils(fat or skinny coils)
Blades vs poles when adjusted close to the strings
Direct Alnico vs iron core
I was lucky enough to find the stats on my pups in my Squier Bass VI. Convinced fender/Squier didn't put much work into designing new pickups so the used the same formula as the VM Jaguar pups.
Played around with a RLC calculator and on paper it looks like I only need a 150pf for the middle/bridge pup and 300pf with my 10' 345pf cable. This should bring the resonance down from an unloaded 8khz to about 3-3.5khz for the neck n middle and from 5.7khz for the bridge to about 2.9khz.
On paper it looks good but after I rewire it I'll try out loading caps
As for the 4n7 everyone suggests is the same value telecaster players used for their cocked wah tone
Played around with a RLC calculator and on paper it looks like I only need a 150pf for the middle/bridge pup and 300pf with my 10' 345pf cable. This should bring the resonance down from an unloaded 8khz to about 3-3.5khz for the neck n middle and from 5.7khz for the bridge to about 2.9khz.
On paper it looks good but after I rewire it I'll try out loading caps
As for the 4n7 everyone suggests is the same value telecaster players used for their cocked wah tone
If you have pickups that resonate even unloaded at 8 kHz, that's pretty unusual. Then again, some of the Squier stuff is wound with thicker gauge wire and fewer turns (lessens the chance of breaking the wire, allows them to wind very fast). I know a kid with an Affinity Strat, and I went in and loaded those pickups with loading caps and shorting coils (oops - another secret out of the bag). It went from a strident, thin sounding guitar to a very nice strat tone with about $2 in parts.
This guy at another forum did the analysis of the Jag pups, and assuming there are the same formula but as a 3 pickup set for the VI. I measured my resistance and induction of each pup and was about 0.5 under of each as to his reading.
Squier Jaguar - Pickups
Squier Jaguar - Pickups
