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

[pinkjimiphoton]

a quick demo of a modified guitar tone pot i came up with, based on ideas i found at Joe Gore's tonefiend website... a combo of low and hi pass filter on one pot, effectively leaving your tone neutral about half up, treble and bass cut all the way down, and a reduced load resulting in a psychoaccoustic(at least) BOOST in the treble and bass output of the guitar. it's pretty hip, check it out if ya got some time to kill and are bored. only requires one extra part.
here's a layout. use a 500k audio taper pot for best results.



one more from the tone dungeon of Stupid Pedal Tricks with Pink Jimi Photon .,,,

[rutabaga bob]

Neat little mod!
Glad to see you back 'on the air'.

[pinkjimiphoton]

hi larry

to be clear, when i say "boost" i mean it as in it "sounds like it boosts..."

kinda like wampcat saying his 2399 circuits are "analog".. they aren't, but to many guitarists they don't understand that shit.

the cool thing is the 22n cap acts like a "bleed" and seems to reduce the load on the circuit from the tone pot.
i wish the guitar in the video was louder to be easier to hear, but gineen was kickin the floorboards already lol

be good bro... rock on

[Jdansti]

Cool! My 1990 HM Strat has two knobs also and the tone control sounds like your video. The pot has a detent in the middle of the sweep so you can feel where the center point is.

I wonder if this would work with stompboxes that have a single tone control.

Thanks for sharing!

[Tony Forestiere]

The pot has a detent in the middle of the sweep so you can feel where the center point is. I wonder if this would work with stompboxes that have a single tone control.

Interesting idea.

[bean]

Jimi, put away your Mike Matthews costume...Halloween isn't for another month! 

[chuckd666]

Jimi, what kinda guitar is that?

[pinkjimiphoton]

Cool! My 1990 HM Strat has two knobs also and the tone control sounds like your video. The pot has a detent in the middle of the sweep so you can feel where the center point is.

I wonder if this would work with stompboxes that have a single tone control.

Thanks for sharing!

hi john,
you have a fender tbx tone control, it does the same thing but needs a dual pot with different values, 2 caps and a resistor. i have one on my strat i installed years ago. this actually works better to my ear.

what's hip is it can cut the bass a bit too, when turned down, leaving a fairly phat but somewhat nasal tone. when it's cranked, it's almost like taking itself out of the circuit. you can't really get "more treble" but you can most def get closer to no tone control load i guess.

works great with distortion... you can literally set your guitar volume wherever is appropriate and sweep from rhythm to lead right from your guitar.

it should work great in a stompbox i'd imagine. i've used similar in a couple of the suzy q's and when ya think about it, it's just a simplified tbx.

[pinkjimiphoton]

Jimi, what kinda guitar is that?

hi   chuck,
i went to the dentist one day to get my newest set of chompers, and as i was firing up a doob on the way out the door i noticed a guitar neck sticking out of a bunch of rubble overflowing from a dumpster next door.

so of course i had to investigate.... what i found was a very poorly assembled les paul jr kit.... assuming saga or something similar... that someone had messed up.
it was a white single cut with on dogear p90 on it and a wraparound bridge. it had been spray painted white THICKLY.... lotta runs and very uneven. but the deal killer that got it in the garbage apparently was that someone had stripped the holes in the neck.
so their next bright idea, judging fromt the crust in the neck pocket, was a zealoud application of wood glue... kinda like a solder newb with huge GLOBS thinking hey, more is better, right?
but they didn't stop there..

when that failed, likely cuz they never bothered to remove the 1/2 inch of paint from the cavity and neck. they stuck metal inserts in the hole of the neck and tried to screw it in again, never removing the old glue. this of course failed, so it looks like they squirted a half bottle of elmer's yellow in the neck pocket and tried clamping it with a c- clamp right on the frets.

so now they @#$%ed up the frets, too. i guess they gave up on it.

so i took it home, and started messing with it. i had told my brother eddie i always had a thing for les paul dc's, so he made it into one... took a chunk of good mahogany off a destroyed sg we use for donor wood, and made the neck so it would glue in with a long tenon and did so.

last week we got to sanding, sealing, and painting with some vintage acrylic laquer, and about a half gallon of clear laquer on top of it.

the schaller bridge on it is a RCH too wide so i'm awaiting a couple others to see what fits best.

the tuners are whatever was on the original, some enclosed decent quality ones.

the pickup is a "caliguitar" side by side coil mini humbucker in a soapbar case. i LOVE these pickups. they're cheap, toneful, and scream... i wired it up to a 500k linear volume pot's input, from the wiper it goes to the tone stack above on the tone pot, which is a 500k audio taper pot with a dpdt switch on it. and that's pretty much it!!

so it's another jimi and ed frankenstein. her name is lola in honor of his little dog who just recently passed away.

[ashcat_lt]

Ummm...  When the pot is all the way up, the highpass cap is shorted and has no effect on the "loading" or the tone.  If you really think it sounds different all the way up than it did before this mod then you've either also changed something else or forgotten what it sounded like before.

[Mark Hammer]

The control is essentially an adaptation of the classic tone control found on early tweed Fenders like the 5E3 Deluxe and 5F2 Princeton, as below.  (Note that the Volume control is the pot whose ground connection points down, and the Tone control has the ground connection pointing up.) 

As in your illustration, the wiper of the tone pot connects to the input lug of the Volume pot.  One leg of the Tone pot connects to a larger-value cap going to ground (for treble bleed), and the other leg of the pot goes to a smaller-value cap that straddles the input and wiper lugs of the Volume control.  That part allows for variable treble to bypass the volume pot (keep in mind the Volume pot wiper is going to the output jack).

What is different here, in your drawing, and I assume Joe's, is that the "other" leg of the Tone pot does not place resistance in series with the treble bypass cap, but is in parallel with it.

What does this do that is different?  Since the "treble" side of the tone pot, and the other outside lug, goes to the output jack, that variable resistance is in parallel with the leg of the volume pot between input and wiper.  As such it will interact with the Volume pot setting in interesting ways.

The caveat I will note is that the Fender tone control was really designed for use with a Volume control that was rarely at max.  That is, the most trebly-to-woofy variation was obtained when the Volume was turned down.  This is, of course, how "loudness" switches on hi-fi amps were intended to function - as a compensation for perceived loudness at lower volumes.  The treble cut aspect works at any volume setting, but the treble enhance only works at lower volume settings.

In this application, I would imagine that at full volume, there is no effective treble enhance.  The treble enhance only kicks in when the volume is turned down at least a little bit.  As such, the usefulness will depend on how you like to set your Volume controls, and how much you like to tinker with it.  I'm not sure if it would work for Jeff Back or not.  he likes to crank the amp and keep his guitar volume down, for loading effects, to produce his signature tone.  Turning up would reduce the treble enhancement.  But then, since he's cranking his Marshall, taming a bit of the treble as he pushes his Marshall harder is probably a useful quality.  I'll have to ask him next time I go downstairs for coffee. 

[pinkjimiphoton]

Ummm...  When the pot is all the way up, the highpass cap is shorted and has no effect on the "loading" or the tone.  If you really think it sounds different all the way up than it did before this mod then you've either also changed something else or forgotten what it sounded like before.

the reason it gives the illusion of a "boost" is that when turned low, it cuts treble and bass, and when full blast the .oo2 cap bypasses the pot.
maybe i'm explaining it wrong, all i can say is try it and see if ya like it. you'll either dig it or not.

[ashcat_lt]

maybe i'm explaining it wrong, all i can say is try it and see if ya like it. you'll either dig it or not.

Not so much that you're not explaining correctly.  I think you're misunderstanding what's happening here.  That cap bypass the series portion of the pot when it's turned down.  Turned all the way up, there is no series resistance to begin with, and the cap is shorted so not doing anything at all.

All the way up should be exactly like any other tone control with those pot/cap values turned to 10.  Sure, it'll probably sound like a boost, but only compared to having it turned down where you're actually cutting things.  I for one consider 10 on most guitar T pots to be the "normal" sound, with lower settings being a modification thereof.  This is no different at all, except it also cuts bass as you turn down.

[pinkjimiphoton]

hahah, yeah, like i said it's a "boost" like 2399 delays are "analog".
it gives a PERCIEVED boost. not a real one. remember, that description is for guitar players with no concept of what it's doing but what it "sounds like".

something seems to be different. but it could be cuz as you turn it up, the bass cut and treble not-cut gives the percieved effect of a boost.

and i still suspect that small cap has something to do with it, as the audio signal is always going thru it. the only thing that changes is the resistance in parallel.. part of the purpose of a bypass cap is to "bleed" frequencies across the pot's wiper and input or output. in this case i suspect it's doing a little more there than you may think, but hey, i'm no ee, just a hack having fun so it's all good.

i think mark came close to describing it. it is wicked interactive with the volume control and offers an improved range to the venerable old school one. not saying i'm right or you're right, saying it's above my paygrade but it sounds good and some folks may find it useful to get a bit more mileage out of two knob guitars.

back in the old days, guitarists were taught to set up their tone with all the guitar knobs half way up so ya got wiggle room to work with. i never ever leave tone knobs cranked, but i use all the knobs on my guitars constantly. if you don't, this would have no significance to ya.

it's all good bro. try it out and see if ya like it. it doesn't sound or react like any other tone control on any of my 40 some odd guitars.

what the hell happens when ya put a sine wave thru a cap? caps block dc, and filter ac (audio) afaik but again, i'se a hack with a breadboard

its similar to the fender circuit mark posted, one of joe's friends pointed that out on facebook too.

so my question is then, what effect does the .0022 cap have on the guitar signal? it's always in the circuit, cuz the signal is either going straight thru it, or thru it and a parallel resistance at all times... whether the .022 cap is being used or not. would seem to me the smaller cap would be bypassing at least some of the signal around the pot, which may be why it seems to "boost" as well... definitely getting more output than the stock control. noticeable. like taking a blanket off the speaker.

all i can say is try it. maybe somebody can do a circuit sim and figure it out?

[ashcat_lt]

I'm glad you've found something you like, and that's really all that matters.  I don't want to argue much more about this, but...

and i still suspect that small cap has something to do with it, as the audio signal is always going thru it.

NO.  When the pot is turned all the way up, the wiper is connected directly to the CW lug.  That means the two ends of that cap are connected to each other.  That means the cap is shorted, there is no signal going through it, it can't and won't affect the signal at all period, you could just take it out, it is doing nothing.

I don't know anybody who turns down their T pot to 5 and considers that to be the "normal" tone, but even with a standard T pot, if you were that kind of guy, you could say that you get a treble "boost" as you turn it up.  I guess it's all relative.

I'll be done now.

[robthequiet]

Just for kicks, also note the Greasebucket tone control, which shares some aspects of the jimiphoton config. I tried it and found it really subtle, almost as in why bother, except that it did seem to make a difference in how the breakup worked at the amp, giving it a softer edge at the distortion threshold. Also seems to shift the resonant freq, but that could be imaginary. From PremiereGuitar...

[Gus]

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

[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.

[pinkjimiphoton]

I'm glad you've found something you like, and that's really all that matters.  I don't want to argue much more about this, but...

and i still suspect that small cap has something to do with it, as the audio signal is always going thru it.

NO.  When the pot is turned all the way up, the wiper is connected directly to the CW lug.  That means the two ends of that cap are connected to each other.  That means the cap is shorted, there is no signal going through it, it can't and won't affect the signal at all period, you could just take it out, it is doing nothing.

I don't know anybody who turns down their T pot to 5 and considers that to be the "normal" tone, but even with a standard T pot, if you were that kind of guy, you could say that you get a treble "boost" as you turn it up.  I guess it's all relative.

I'll be done now.

much more.... lmao.

ash, dig it man. when the pot is up all the way, yes, you're right. but the part you are missing is  all the way up, the signal is shunted thru the pot and the larger cap to ground, thereby rolling off the bass.

but the small cap is ALWAYS in the circuit bud.  look at where the signal goes in and comes out. it goes thru the .0022 at all times. it is literally no different in application as a treble bleed cap in this case., seriously. just a lot bigger than the typical 100-1000p, so it lets more frequency thru.
yes, when the pot is dimed, the .022 cap is effectively out of the circuit. but the .0022 is NEVER out of the circuit. the entire signal runs thru it. the output of the guitar goes to the wiper of the pot.  one side shunts signal thru a cap to ground. the other side changes resistance in parallel with it's cap, the .0022. but that cap is never out of the circuit.  it's ALWAYS in the circuit in fact. look at the diagram again. for all intents the output of the entire guitar... whether from pickups, volume pot, or switch, is ALWAYS going thru that little cap 100% of the time. it has to, cuz it is in series between the output of the guitar and the output jack. that's the part i don't think you're getting.
think of it as an upside down volume control, or one wired backwards. instead of having the third pin grounded, it shunts thru a cap. there's your basic normal guitar tone.  across the wiper and input of the pot is where the .0022 is. it is wired exactly the same as a treble bleed/shunt/bypass cap, but considerably larger. it is ALWAYS in the circuit.

part of the way treble bleeds work is to allow an easier path for the treble frequencies to bypass the load of the pot. this does the same thing.
when you turn the pot up all the way, it's bypassing the big cap, true, but the little cap is still "bleeding" frequencies across it. cuz the signal is passing THRU it.  when ya turn it down, it becomes a bass cut. when you turn it up, it acts as a shunt to bleed frequencies across the load of the pot.

when you reduce the losses imposed by a tone pot or tone stack, you gain more output. always. fact of life.

when you bypass a volume control, you get more treble available as les gets shunted to ground.. this always results in a more easily heard top end, cuz the top end is bleeding past the pot.

in this case, when the pot is full blast, it has the same effect as a volume pot with a treble bleed turned very low... except the treble bleed is more of an upper mids bleed, cuz it's hugely larger than what is needed for treble bypass.

i mean @#$%, dude, you can bypass a volume pot with a huge cap... i used to put .22 caps in strats on a switch for a huge "boost" when the guitar wasn't dimed. when the guitar is pegged, it's pretty much out of the circuit. as you turn down it bleeds thru a lot more guitar signal, which could be handy for switching to leads. hit a switch, and POW. if ya don't believe me, try it.

in this case the small cap is always in the circuit. either as a hi pass filter when in parallel with the pot, or as a shunt for the audio to bleed frequencies across it. this really isn't rocket science.

like i said, if you're one of the guys who leaves your knobs on 10 all the time, this won't make any difference to you. i'm not like that. but whatever. you can argue til the cows come home about yourself being right, or you can try it yourself and see if it works as described, or franky ya can stfu if ya want to. i don't really care, choose one.

what happens when you put the audio from a guitar thru a .0022 cap? audio is ac, so it should pass right thru. but, much like in a fuzzbox, the SIZE/VALUE of the cap can make all the difference in the frequency response fo the fuzz. put a real small cap in and ya get a treble booster. same basic concepts.

so instead of telling me i'm wrong, which you may well be right and i'm not arguing about it, either try it yourself or run a circuit sim or whatever ya feel is necessary.  but ya don't have to be a dick dude. me either. and i'm beginning to lean in that direction.

peace

[pinkjimiphoton]

Just for kicks, also note the Greasebucket tone control, which shares some aspects of the jimiphoton config. I tried it and found it really subtle, almost as in why bother, except that it did seem to make a difference in how the breakup worked at the amp, giving it a softer edge at the distortion threshold. Also seems to shift the resonant freq, but that could be imaginary. From PremiereGuitar...

yeah, i tried the greasebucket out, and didn't like it. it really doesn't do much but roll off a little bite if ya have enough distortion to play with and uses more parts. my bro bob has one on one of his strats, he thought it was broken cuz he said it didn't do anything. well, it did, but at the levels of filth he uses and stacks, the subtlety is pretty much lost.