stupid pedal trick... photon's stupid simple guitar tone control

[pinkjimiphoton]

Making a sim of the circuit with the pickup and cable and input loading should help to tune the circuit for each guitar amp setup
Here is a link to some P bass sims
http://www.diystompboxes.com/smfforum/index.php?topic=93990.msg809877#msg809877

thanks gus, i'd love to see a circuit sim to see what it's doing, but that's way above my paygrade. i will look at it shortly.

[pinkjimiphoton]

Sounds good, Jimi! Cool idea. I'll have to give this a try.

When the tone is turned down, I almost hear some vibey Trower-ness in your sound.

try it out doug, you may like it bro. it's a much different sound from the usual tone control on zero mud. seems to roll off treb and bass and leave more midrange intact.

again, i'm no ee, i just hack shit together til it sounds good. i've added bass cuts to most of my guitars now for several years and this is a good way to squeeze it in on a two knob guitar and still keep me happy.

of course, i'm OLD   and old school, so i actually use the knobs on my guitars... and always designed my fuzzes to be as interactive with them as possible.  i rarely EVER have my guitar dimed.

i tend to keep the amp cranked, the guitar real low and use a real light touch so i have dynamics. something the world seems to have forgotten about .

rock on bro... outta here, had all the raving i care to deal with.

[DougH]

Sounds good, Jimi! Cool idea. I'll have to give this a try.

When the tone is turned down, I almost hear some vibey Trower-ness in your sound.

try it out doug, you may like it bro. it's a much different sound from the usual tone control on zero mud. seems to roll off treb and bass and leave more midrange intact.

again, i'm no ee, i just hack shit together til it sounds good. i've added bass cuts to most of my guitars now for several years and this is a good way to squeeze it in on a two knob guitar and still keep me happy.

of course, i'm OLD   and old school, so i actually use the knobs on my guitars... and always designed my fuzzes to be as interactive with them as possible.  i rarely EVER have my guitar dimed.

i tend to keep the amp cranked, the guitar real low and use a real light touch so i have dynamics. something the world seems to have forgotten about .

rock on bro... outta here, had all the raving i care to deal with.

Part of the mid thing you are hearing might be due to the .022u cap. I've swapped out the typical .047u tone cap on a couple of my guitars and stuck a .022u in there, and it does get a nice mid bump when you turn it down all the way. There's like a resonance or something in the way it interacts with the pickup. And it sounds really nice with a fuzz for playing leads. Instead of being muffled, it has more of a nasal sound.

[stallik]

i tend to keep the amp cranked, the guitar real low and use a real light touch so i have dynamics. something the world seems to have forgotten about .

So true Jimi. It's a whole new sonic world that way round. Just a bit scary when you forget and dime the guitar through a stack in a bedroom 

[ashcat_lt]

Look, I certainly appreciate your contributions around here.  A lot of the things you come up with really are pretty cool.  Heck, I can definitely see how this would work well for a lot of people.  But you've as much as admitted that you don't really understand what's happening here.  It IS exactly like a treble bleed on a Volume pot.  You are completely wrong about how it actually works, but I don't know how to explain it any more clearly than I already have.

[pinkjimiphoton]

Sounds good, Jimi! Cool idea. I'll have to give this a try.

When the tone is turned down, I almost hear some vibey Trower-ness in your sound.

try it out doug, you may like it bro. it's a much different sound from the usual tone control on zero mud. seems to roll off treb and bass and leave more midrange intact.

again, i'm no ee, i just hack shit together til it sounds good. i've added bass cuts to most of my guitars now for several years and this is a good way to squeeze it in on a two knob guitar and still keep me happy.

of course, i'm OLD   and old school, so i actually use the knobs on my guitars... and always designed my fuzzes to be as interactive with them as possible.  i rarely EVER have my guitar dimed.

i tend to keep the amp cranked, the guitar real low and use a real light touch so i have dynamics. something the world seems to have forgotten about .

rock on bro... outta here, had all the raving i care to deal with.

Part of the mid thing you are hearing might be due to the .022u cap. I've swapped out the typical .047u tone cap on a couple of my guitars and stuck a .022u in there, and it does get a nice mid bump when you turn it down all the way. There's like a resonance or something in the way it interacts with the pickup. And it sounds really nice with a fuzz for playing leads. Instead of being muffled, it has more of a nasal sound.

imho .047 seems to roll off the highs about an octave lower than it should and most def messes with the midrange. i've tried .033 and .039 too, my fav is .022. my bro adam swears  by .015. i guess it's whatever works for ya.

as a side note, i apologize publically to ash, i think there's a misunderstanding in what i'm saying. we don't have to agree, but we don't need to go back and forth either. as i said repeatedly "GIVES THE ILLUSION OF" as in "2399's being analog"... which i had a similar reaction to with brian wampler a while back. i asked if he didn't feel he was being misleading by saying his faux echo was an analog delay and his reply, similar to mine, is that it's how guitar players describe stuff, not how a tech sees it and i can grok that.

but again... when you bypass a pot, what happens? as you decrease the resistance, more signal bleeds thru. this is, again, for all intents a backwards volume control doing double duty as a treble cut.

ayyyy makes my head hurt.

hoping gus can maybe run a falstad sim or something to see what the hell is happening. peace.

[pinkjimiphoton]

  It IS exactly like a treble bleed on a Volume pot.  You are completely wrong about how it actually works, but I don't know how to explain it any more clearly than I already have.

as i have said it is exactly like a treble bleed on a volume pot. yep. the part you're not getting is the audio is always going thru it. yes, i did say i don't understand how it works like that. but it does. i am again no ee bro. but you're like don quixote on this, why?

i've explained and re-explained what it is, what it does, and why/how i think it works. there's something about the way the cap is bleeding signal.
one side is a bog-standard tone control. the other side cuts bass, but acts as a bleed. it's always bleeding signal around the pot, whether the pot is all the way up or all the way down. even with the volume pot completely down at "zero" there's usually not a complete short. could be anywhere from fractions of ohms to an ohm or two when it's "shorted" or completely off.

one thing i've learned is to never expect absolutes to be absolutes, and to understand averages are fine within tolerances.

is it easier for the signal to bleed across the cap, or the small resistance of the pot when it's "off"? i'm guessing the cap, as when off, it's rolling off bass, rolling off treble, and bleeding midrange.

hey, if i'm wrong i'm wrong. i'll even say it now... i am wrong. alright?

but that shit don't matter, cuz like a lot of other things, sometimes "wrong" is right. trust me on this. shit, trust yourself.

and remember, not all of us are young bucks with our guitars on 10 expecting to find tone like that. to my ear, it don't exist, and if i'm on 10, either i'm looking for all-out fuzzy mud, or more likely my rhythm section is too loud.

tone controls weren't put on guitars to keep on 10. the whole idea was to be able to compensate for differences in amplification from the guitar. playing a muddy amp? turn it up some. playing a bitey amp? roll it back. it's not rocket science, and when i started doing this they actually, believe it or not, advised you to set your amp up with your guitar half way up so you can have wiggle room. if you haven't tried it, i suggest you do.

again.. you ARE right, a "boost" is impossible from a tech standpoint. from a musical standpoint in "guitar speak" that's what it sounds like. if i try and explain how filters work to most guitarists, their eyes glaze over. if i tell them it will affect their tone differently from what they're used to, THAT they can understand. got it?

rock on, ya crazy bastids....lol

[thermionix]

Part of the mid thing you are hearing might be due to the .022u cap. I've swapped out the typical .047u tone cap on a couple of my guitars and stuck a .022u in there, and it does get a nice mid bump when you turn it down all the way. There's like a resonance or something in the way it interacts with the pickup. And it sounds really nice with a fuzz for playing leads. Instead of being muffled, it has more of a nasal sound.

I've been using a .01 tone cap for years now (P-90s and humbuckers).  Running through a "normal" distortion or overdrive sound, I can turn the tone pot down all the way down, and it becomes a singy, nasally, stuck-wah fuzz-type tone.  Pretty cool.  You would think it was a tuned filter if you heard it.  I don't know if it matters what type, but I use big ceramics robbed from silverface Fender amps.  There's always a few of those around from blackface conversions.

[Ben Lyman]

I've been using a .01 tone cap for years now... big ceramics robbed from silverface Fender amps

Are they kinda like these? I grabbed this bag for a buck so I could have them around for... um, well I don't know why but I know they must be good for something.

This thread reminded me of my old 1972 Telecaster Deluxe, back in the 1980's Ralph Novak did something to the tone pot and when you turn the knob down, it definitely gives a "perceived midrange boost" as it were. Maybe someday I'll look in there and see what he did.

[thermionix]

Good score for $1, even if you only end up using a few of them!  The ones I've been using are bigger than that, maybe nickel size (1600V?) but I highly doubt that matters.  Seriously, try one of those as a tone cap, and see what I mean.

I've never tried one with Fender single coils, only P-90s and humbuckers, but I assume it would have about the same effect.  For experimenting, it's easier to get into a LP or SG than a Strat anyway.

[pinkjimiphoton]

well, i rocked it live last nite.
i was only gonna use the new guitar for the first set, but i used it the whole nite.
for ME, it's pretty much perfect. i could dial in any primary kinda tones i needed. no mean fete for a two knob guitar.
there's a switch on the tone knob that lets me choose series or parallel on the "caliguitar" p96nd (neodymium p90 sized humbucker i've been using in a lot of builds lately) and as mr. hammer predicted, HUGELY interactive.  got most of the same kinda sounds i usually get with two knobs, so i'm happy with it.
it acts kinda like a broken tone control, lol... it's kinda neat. as you decrease bass content, it decreases gain as well. very cool... but like i said, only if you use your knobs.
if'n anybody actually tries it, let me know.

[ashcat_lt]

Posted this earlier today but it must have been lost when the spam was fixed.

I think these are reasonable estimates for the pickup in your video.  Definitely close enough for this kind of thumbnail analysis.  The top circuit is yours, bottom is a standard T pot with the same values.  I used about 10ft of average cable and a 1M load at the amp end.

The colored traces here are with the pot most of the way down.  It occurred to me after I did the uploaded everything that 1% of 500K is still a significant amount of resistance, but 5spice freaks out when you try to do a log sweep from 0, and I think you get the idea.  I can try with a smaller value if you want, but it'll be tomorrow.

This is about halfway up on a log pot:

This one is deliberately short of all the way up since there was talk about possibly having some little bit of resistance even all the way up.  If your pot has 500 ohms when it's all the way up, then it's broken, so this is an exaggeration, but makes my point pretty well.  The biggest difference between the two curves here is about 0.004db with the regular T being louder.  If you can hear that difference... 

hope it helps

[pinkjimiphoton]

thanks ash,
i really have no idea what any of this stuff means, but i think it shows i don't know what any of this means.

all i can say is try it. it may be brillinat for ya, or it may be poo

for me, it seems to do what i wanted...  it lets me roll off the treble and bass with one knob. that was the goal.

it's almost a volume level control, but it just cuts the treb and bass. does it make any difference when the pot is full blast?

what does the .0022 cap do to the tone, as the guitar signal is always going thru it?

a lot of peeps seem to think i understand way more of this stuff than i do, but i'm just a hack with a breadboard willing to "let the magic smoke out" .

[ashcat_lt]

Oh hell, I never use tone controls.  In fact, I usually take them out of any guitars I rewire for myself.   

If you're happy that's cool, and like I said I'm sure others will find it useful.

[pinkjimiphoton]

i just looked at it again, and what you have is NOT my circuit. it's similar, but not correct.
you show the tone pot as having the input at the top, and the output from the wiper.

that is backwards from what i did. in mine, the input is to the WIPER. one side goes to the .022 to ground. the wiper connects to the remaining pin with a .0022 cap. the output is from this node, not the one you show.

that's probably why the sims look so similar... they are.  the only dif is you're shorting out the cap with a jumper in both your drawings.

but that is not my circuit. i would imagine if you change your input stuff to my circuit, you will get different eq curves from what you've posted.

your circuit is pretty much a standard tone control with a treble bleed at the top of it.

my circuit is "panning" between a low pass filter and a high pass one, with the output coming from the outside of the low pass filter.

it's not the same application or circuit.

not to add to the confusion

but we're not talking about the same animal here. what i'm doing is faking a variable cap. it's almost like what i did with my transmission overdrive a few years ago, with a pot to "pan" between in400x and 1n34 diodes. you could dial in the level of clipping with it, which is what got me thinking about adapting the common tone control.

i believe that the differences in circuit and application render the sims posted as useless, no offense intended in any way shape or form.
if you could re-do it with the proper circuit, i'd be grateful and interested to see what happens with it.

you may wanna adjust the level of the "guitar volume" pot in the sim too, as the volume and tone are ridiculously interactive when either one is less than full.
peace

[ashcat_lt]

i just looked at it again, and what you have is NOT my circuit. it's similar, but not correct.
you show the tone pot as having the input at the top, and the output from the wiper.

Damn, you're right!  Sorry.  I don't believe it makes as much difference as you think, but I'll try again tomorrow.

my circuit is "panning" between a low pass filter and a high pass one, with the output coming from the outside of the low pass filter.

I don't believe that to be true, and you said that it cuts treble and bass at the same time, but we'll see...

you may wanna adjust the level of the "guitar volume" pot in the sim too, as the volume and tone are ridiculously interactive when either one is less than full.
peace

I think I'll leave that part for somebody else. 

[pinkjimiphoton]

lol.... no worries

a low pass filter is in a guitar is a resistance in series with a cap to ground.

a hi pass filter is a cap in series with a resistance to ground

here's the link to joe's webpage on having passive treble and bass controls

http://www.seymourduncan.com/tonefiend/guitar/two-band-ptb-tone-control-useful-easy-cheap-awesome/

here's his hand drawn layout. note in joe's original circuit as shown the bass is cut by turning UP, with full bass with the pot at zero.



i and most of my friends found this kinda counterintuitive so i reversed it. notice in each case, the filter only requires half a pot. if you use the wiper as an input, you can "pan" between the two filters. the output comes from the output of the .0022 cap

also note how he has it wired. he has the low pass filter (standard tone control) but he has the cap going from the wiper to ground. i did the opposite. same thing on a linear pot, not sure of how it may be affected by the audio taper of the pot i used.

on his, he has the wiper and outer lug and the wiper shorted together with the cap between the wiper and the third pin. this is the hi pass filter.

as you can see, all i did was use both halves of one pot to do what both circuits are shown as doing. but instead of using the wiper as the output and only using half of the resistive track on each pot, i used the wiper as the input so i could pan from one circuit to the other. easy breezy.

the only reason i suggested you may wanna change the "level" of the guitar pot is that they don't interact much when the guitar is pegged. all the fun stuff starts when ya start moving the knobs.

all the way down, the treble is shunted thru the cap to ground for the low pass, and i believe at that point as it's going thru just the capacitor, which should be a path of least resistance i think,  so it's acting as a treble bleed... but extending well into the midrange of the guitar. or maybe i just did too much acid. i dunno. could be both

yeah, the diff between the circuit you posted and the one i posted is different enough to create completely different sonic outcomes.

and remember, in MY CIRCUIT, the guitar signal is always passing thru the .0022 cap... either by itself, or in parallel with a variable resistance, which if memory serves makes electrons think they're dealing with a variable cap.

anyways... onwards and upwards