Passive Hi-pass filter for pickups

[PBE6]

Surprisingly not too bad, considering we are aiding and abetting you in a crime against luthiers everywhere

I just did some simulations using different capacitor/resistor pairs, and it turns out that if the series capacitor is too small then it introduces its own volume drop. 1nF and 470k seemed to retain the highest overall volume (only lost about 3dB at the peak), try playing around with values near those.

You may also consider cutting less bass. Less bass is often perceived as more treble since it's usually the overall balance that matters. BTW, were you using an amp/speaker simulator in your DAW? It didn't sound like it. Amp simulators include built-in filters that roll off the treble pretty steeply above 5kHz or so to mimic the treble response of a real speaker cabinet, that may be enough to correct the balance for you. A real amp would do the trick too.

Is this for live use or for recording? If it's for live use, then I can see a permanent physical change being useful. But if you're recording direct to your DAW, the EQ tools available to you are much easier to use and more flexible.

[PBE6]

To calculate Zc, use:

Zc = 1 / (2*pi*C*freq)

Where C is in F (must convert from pF, nF, uF, etc...) and freq is in Hz.

[PBE6]

Honestly, the best way to do this is to use an active EQ as Transmogrifox suggested, either built in to your guitar or as the first box your guitar feeds into. It avoids volume drop issues and is ultimately much more flexible.

[Rock_on]

Honestly, the best way to do this is to use an active EQ as Transmogrifox suggested, either built in to your guitar or as the first box your guitar feeds into. It avoids volume drop issues and is ultimately much more flexible.

I would love to but it's just not my kind of hmm what word should i use... taste? kind of solution? err I mean *scratches head* just want it direct to my interface or direct to amp. Simple as possible :v I hope you get what I mean.

Surprisingly not too bad, considering we are aiding and abetting you in a crime against luthiers everywhere

I just did some simulations using different capacitor/resistor pairs, and it turns out that if the series capacitor is too small then it introduces its own volume drop. 1nF and 470k seemed to retain the highest overall volume (only lost about 3dB at the peak), try playing around with values near those.

You may also consider cutting less bass. Less bass is often perceived as more treble since it's usually the overall balance that matters. BTW, were you using an amp/speaker simulator in your DAW? It didn't sound like it. Amp simulators include built-in filters that roll off the treble pretty steeply above 5kHz or so to mimic the treble response of a real speaker cabinet, that may be enough to correct the balance for you. A real amp would do the trick too.

Is this for live use or for recording? If it's for live use, then I can see a permanent physical change being useful. But if you're recording direct to your DAW, the EQ tools available to you are much easier to use and more flexible.

I also thought of that already, but i'll just try to play around with the pickup height starting with the standard fender suggested height. My bass side is almost flush to the pickguard (super slanted). Though the cut is good with the tone at 4 - 5, I'll go with a bit less bass cut to balance it... atleast it's better than the unfiltered. EWWWWWWWWWWWWW (may i have your opinion on the unfiltered sound? Hahahaha i want to know other people's comment about that yucky sound. This is my guitar for about 3 or 4 years already. I don't have any money to buy a new one.)

both? But most of the time direct to my DAW. I just want it to be versatile as possible cause there may be some time you need this or that.

Oh also, I'm not using any amp sim so I can compare the raw pickup sound. I look for guitar DIs on the internet and look for the one that I like. Not too dark and not too bright, and then with my unfiltered guitar... I then EQ matched it in my DAW with an EQ matching vst plugin that will automatically calculate what to boost and cut so the spectrum is somewhat similar to the reference. Most of the tracks I compared to, rolls of 431hz from my guitar that's where I get the idea of where to cut.

[Rock_on]

To calculate Zc, use:

Zc = 1 / (2*pi*C*freq)

Where C is in F (must convert from pF, nF, uF, etc...) and freq is in Hz.

Just wondering PBE6, I tried 1nf and 470k, 10M and 1M resistor with their capacitors cutting at 338hz-400hz (I forgot the values already) but they are all 0.49 volts out? or 0.5 round off? Why is it not changing? While your example was 1khz which has more frequency that was cut but has 0.7v? If my original sound has 1v, 0.7-0.9v is absolutely acceptable for me. Less than is... I'm a bit conscious about it.

Thanks for explaining tho, now i know that my output was cut in half also.


Assume also that my pickup has 6k-10k resistance. I would guess this would not even get 10k resistance... the sound without the filter is a bit weak for me... maybe 8k? or 7k?

[slacker]

Is your interface designed to have a guitar plugged straight into it? Most are designed for line level signals and they will cut volume and treble if you plug a guitar straight in, this might be part of your problem.

[ashcat_lt]

I haven't listened to the sample, but I'm almost positive that you're actually losing treble somewhere and that is what's making you think there's too much bass.  No working pickup should need this kind of filter. 

1) The question about the impedance of your load from the previous poster is a very good one.  Plugging the guitar into a 10K line input will definitely suck tone.  (It'll also throw off all of your filter calculations)

B)  So we know that you're comparing a humbucker to a single coil which is not exactly apples to apples, but is your reference pickup even at the same relative position along the string?  Like, you're not comparing a bridge pickup to a neck pickup are you?

Anyway, what everybody's trying to say is that this "simple" little filter is actually very complex, and must take into account not only all of the other components in the guitar, but also the cable and whatever is plugged in the other side.  You can't very precisely choose an RC pair without knowing all those other values, and if any of it changes (knobs turned, different cable, amp vs interface) then everything changes. 

[PRR]

If you need a 431Hz roll-off to sound "right", then something is VERY wrong with that pickup or the wiring.

Are you plugged into a proper amplifier or DI? Plugging standard e-guitar into the very low impedance of a mixing console or many DAWs *WILL* suck all the highs off.

Temporarily wire the pickup to a jack (go around all Vol and Tone networks) and see/hear what you get.

The bass is probably right, and you are trying to correct a heavy treble-loss. If the high stuff isn't coming out, cutting all the lows will still leave weak highs.

If the pickup has more than one coil, they may be out of phase; I'm not a pup geek so I don't know how bad a cheap maker can screw this up.

There may be other faults which may require total take-apart to fix.

At some point, a slightly less cheap pickup may be a better path than fooling with this one or adding filters.

[ashcat_lt]

It's a "Strat" pickup - eg Single Coil, but if it was an HB with the coils OoP, it would be the opposite problem and worse.  All of the low harmonics would cancel nea completely, leaving just a random spray of high frequencies and a whole bunch of noise.

[Rock_on]

My interface has an instrument input of course. I'm not losing treble srsly.... it's just that it's muddy.

I also understand I can't choose an exact frequency, close one is enough.

[Rock_on]

Surprisingly not too bad, considering we are aiding and abetting you in a crime against luthiers everywhere

I just did some simulations using different capacitor/resistor pairs, and it turns out that if the series capacitor is too small then it introduces its own volume drop. 1nF and 470k seemed to retain the highest overall volume (only lost about 3dB at the peak), try playing around with values near those.

So I see that you tried a lower value res to make cap value higher.

What about 100k and 0.004uF? And also how do you simulate it in spice? So I can experiment with there.

[PBE6]

Try any combination you want, this is your tone quest. Hint: breadboarding cuts down on soldering time immensely.

There are lots of Spice tutorials out there on the web, just take a look around.

Here's a link that talks about passive guitar electronics:
http://www.buildyourguitar.com/resources/lemme/

It should be a useful starting point for your Spice simulation.

[J0K3RX]

I know this isn't really what you were looking for or asking about but you may give it a try since you are running into a DAW... I have used it and was able to get some pretty good results from it.
http://www.kvraudio.com/product/redshift-pickup-replacer-by-acmebargig

[Rock_on]

Thanks for the help everyone.

J0K3RX, i know that one already but the fact that my pickup is ugly from the first place :v :v and in times that I cannot use amp sims :v.


PBE6, by following the formula you gave me about Voltage, I calculated 1M vs 470k resistor (along with the caps that i forgot and too lazy to find xD) 1M is higher even just by a bit than 470k. They are both 0.49 atleast but 470k almost has no volume drop and cleans up the mud! Tho just a little... but it helps, there's still a significant difference. Can you explain why this happened?

Thanks also for suggesting 470k and 1nF. I was still hoping i can cut a bit more since I guess it cuts at 338 but less? Like... my first one cuts 6db (for example with the 1M resistor) and this time it's like 2-3db only.

I used the calculator this afternoon, 1nF along with 400k cuts at 380hz but the closest are either 330k or 470k. So, yea I guess I'll stick around with this for a while or I dunno, find a close one.