how can i add a mids control to a tube screamer circuit?

[GibsonGM]

Yes ^^   Kind of, what you see is what you get.  Interaction and all that.   So, to dial it in more to what you want, you may need to take the next step to gyrator. Nobody said modding a TS for this kind of behavior would be easy   

[ElectricDruid]

i want it to be big and bassy when the pot is all the way down, and then thin and trebely/clangy when its all the way up

This sounds like a description of "Tilt EQ" to me:



From:
https://sound-au.com/articles/eq.htm#s10

HTH,
Tom

[snow123]

i want it to be big and bassy when the pot is all the way down, and then thin and trebely/clangy when its all the way up

This sounds like a description of "Tilt EQ" to me:



From:
https://sound-au.com/articles/eq.htm#s10

HTH,
Tom

lol i already got the bass cut control to a point that im super happy with. heres what it looks like:

[GibsonGM]

Well, sounds like you want CONTROL, man...you'll need some more active devices to get that   Like, a dual opamp.
Here is one from my private stock...but it takes another chip.  It can probably be done easier with a gyrator of some sort, but I like this one...can move the freq. around by playing with values.

Use this power responsibly.

[snow123]

Well, sounds like you want CONTROL, man...you'll need some more active devices to get that   Like, a dual opamp.
Here is one from my private stock...but it takes another chip.  It can probably be done easier with a gyrator of some sort, but I like this one...can move the freq. around by playing with values.

Use this power responsibly.

but where do i put that?

[bartimaeus]

Well, sounds like you want CONTROL, man...you'll need some more active devices to get that   Like, a dual opamp.
Here is one from my private stock...but it takes another chip.  It can probably be done easier with a gyrator of some sort, but I like this one...can move the freq. around by playing with values.

Use this power responsibly.

but where do i put that?

depends on how you want it to sound? you could stick it at the start or at the end.

personally, if i was adding such a powerful mids control, i'd also modify the tubescreamer bit to cut less bass. otherwise, the mids control will just feel like a volume control.

[FiveseveN]

where do i put that?

I hope I can articulate this in the most constructive way: learning the fundamentals takes way less than running into random problems and waiting for someone to show you around.
If you start with
http://www.geofex.com/article_folders/tstech/tsxtech.htm
https://www.electrosmash.com/tube-screamer-analysis
Handbook Of Operational Amplifier Active RC Networks (PDF)

You should become fluent in this stuff in a couple of days.

[GibsonGM]

The trouble with this stuff, snow, is that WE can't design YOUR mid control for you. We can show you the basic ways (and there are many) to filter mids, but where it goes and how much you need, what actual cutoff frequency and so on, is gonna have to be up to YOU, the designer   You've already bumped up against limitations - cut bass, some mids go too, etc.   All of this is due to the afore-mentioned fact that it cuts bass and high, and leaves mids.  If you go in there to work on mids, you're GOING to affect Lo and Hi just by its own nature.   You're kind of trying to filter a filter lol.

The super mid control I posted was more to show you how complicated it can get than for you to actually use, tho you might.  But you're making an entirely different pedal at this point!    IMHO, I'd accept a modded TS in the form of the "Timmy" and move to the next pedal...something with diodes outside the loop like a Guvnor, with an actual tone stack you can mess with.    NOTHING will give control like an EQ after a pedal   Suggesting maybe some active filtering might be in your future. 

[snow123]

wait ive got the active mids control close to what i want, but i just want it to lower the mids when the pot is down, and when the pot is up, theres more mids. how would i do that?

[GibsonGM]

I think the answer isn't clear because you don't know how a tone stack works, Snow...and how simple tone controls operate...in a TS (and tone stack), you CUT low and high, and that leaves the mid.  The TS is a lowpass and highpass, and cuz of where the 'hump' comes from - in the feedback loop - it's hard (impossible?) to make is a versatile control, so to speak.   And that's ALSO where the clipping is happening, so the mids are a big part of that too.  We showed you how you can cut the mid, too...I think, but not cut AND boost in 1 thing.   Now, to do BOTH cut AND boost mid in ONE control requires more complication...the circuitry just isn't there in the TS.  Some variation of the Big Muff tilt control, and other tilts like Tom posted, might do a bit more - but probably not what you're asking.  (sorry to ramble that was 2 parts I mashed together)

The 'thing' I posted that does this, with 2 opamps, is pretty much the name of the game. It's close to an EQ, actually.   Not a passive tone control...the opamps are involved in how it works.

You CAN mess around with what you've got, and see if you can get a better curve, but it'll probably always be kind of 'mellow' like that, unless you get more complex.   And then, it becomes an all-new pedal, not a TS, right?  *shrug*   Most ppl try to bring the low & high back to make it 'flat mids'...

[snow123]

I think the answer isn't clear because you don't know how a tone stack works, Snow...and how simple tone controls operate...in a TS (and tone stack), you CUT low and high, and that leaves the mid.  The TS is a lowpass and highpass, and cuz of where the 'hump' comes from - in the feedback loop - it's hard (impossible?) to make is a versatile control, so to speak.   And that's ALSO where the clipping is happening, so the mids are a big part of that too.  We showed you how you can cut the mid, too...I think, but not cut AND boost in 1 thing.   Now, to do BOTH cut AND boost mid in ONE control requires more complication...the circuitry just isn't there in the TS.  Some variation of the Big Muff tilt control, and other tilts like Tom posted, might do a bit more - but probably not what you're asking.  (sorry to ramble that was 2 parts I mashed together)

The 'thing' I posted that does this, with 2 opamps, is pretty much the name of the game. It's close to an EQ, actually.   Not a passive tone control...the opamps are involved in how it works.

You CAN mess around with what you've got, and see if you can get a better curve, but it'll probably always be kind of 'mellow' like that, unless you get more complex.   And then, it becomes an all-new pedal, not a TS, right?  *shrug*   Most ppl try to bring the low & high back to make it 'flat mids'...

yea, im really happy with how the active mids control is turning out, i basically just want to swap the "1" and "3" lugs, so when i turn the pot down, it will turn the mids down(and vice versa), 'cause rn its turning the mids down when i turn the pot up. but im not sure how to go about doing that. or i might just be misunderstanding how the pots work in LTspice lol.

[GibsonGM]

    Ooooh....not sure what pot you have - my pot is different than yours LOL.  I imported it from some collection of stuff on one of the old LT Spice groups.

Post the actual schematic you want to work from (since there are several things floating around on this post) and we'll turn you around.

One way to resolves this in LT is to remove the pot, use 2 resistors to simulate it, wiper is the mid-connected node.    You increase one value while decreasing the other (1k on one side, 99k on the other for ex.) and see what this does to your circuit. Then you do the mental gymnastics to figure out which represents 'clockwise' and 'counter clockwise' on an actual pot.  Hope that makes sense!    I mean - it doesn't matter in simulation, but if you build it you need to know what to connect to which side, sure...

[snow123]

  Ooooh....not sure what pot you have - my pot is different than yours LOL.  I imported it from some collection of stuff on one of the old LT Spice groups.

Post the actual schematic you want to work from (since there are several things floating around on this post) and we'll turn you around.

One way to resolves this in LT is to remove the pot, use 2 resistors to simulate it, wiper is the mid-connected node.    You increase one value while decreasing the other (1k on one side, 99k on the other for ex.) and see what this does to your circuit. Then you do the mental gymnastics to figure out which represents 'clockwise' and 'counter clockwise' on an actual pot.  Hope that makes sense!    I mean - it doesn't matter in simulation, but if you build it you need to know what to connect to which side, sure...

heres the schematic:

[GibsonGM]

Well, THAT"s fancy      Try this to 'test' your pot so you know which way the "%" is sending the wiper.  Check output voltage at OUT for a low percent, and a high, you should be able to figure out the rest (if not, post in "Simulation" for more discussion...).  You CAN rotate the pot (CTRL+R) and flip it (CTRL+E):




EX: With my pot, the 'low percent', .1, is at the cold end (L), meaning the wiper is .1 from that end, = nearly 10V at OUT...  .9 would send it nearly to the other end, min. voltage at OUT... HTH

[GibsonGM]

To remain on topic (ha ha), Jack Orman came up with this a while back, I just rediscovered it. if you can get a wah inductor, you CAN make a mid cut/boost! Already invented and possibly worth exploring for you.  See "AMZ Tone 6" and 7.

http://www.muzique.com/lab/tstone.htm

[ElectricDruid]

heres the schematic:

Nice work! That baxandall-style mid cut/boost control is the same layout as I used in the Hard Bargain, so I happen to know that pot to the input end is "boost" and pot to the op-amp end is "cut". If your pot is working back to front, you can just swap the lug 1 and lug 3 connections over. It's symmetrical around the "flat" setting in the centre, so there's no problem.

HTH,
Tom

PS: Separate issue entirely, but why 1u/10K for C7/R10 at the input? Increasing R10 to 1M would give you better input impedance, and then C7 wouldn't need to be so big to keep the bass response.

[snow123]

heres the schematic:

PS: Separate issue entirely, but why 1u/10K for C7/R10 at the input? Increasing R10 to 1M would give you better input impedance, and then C7 wouldn't need to be so big to keep the bass response.

im just using the 1uf/10k 'cause thats what the original tube screamer has

[snow123]

Well, THAT"s fancy      Try this to 'test' your pot so you know which way the "%" is sending the wiper.  Check output voltage at OUT for a low percent, and a high, you should be able to figure out the rest (if not, post in "Simulation" for more discussion...).  You CAN rotate the pot (CTRL+R) and flip it (CTRL+E):




EX: With my pot, the 'low percent', .1, is at the cold end (L), meaning the wiper is .1 from that end, = nearly 10V at OUT...  .9 would send it nearly to the other end, min. voltage at OUT... HTH

oh. i just mirrored the pot and it fixed it.

[snow123]

uhhhh for some reason the step command for the bass cut pot stopped working??

[snow123]

uhhhh for some reason the step command for the bass cut pot stopped working??

IGNORE THIS. that happened 'cause i accidentally typed in 2.2nf instead of 2.2uf for c9. and c9 kinda makes sure there is an actual sweep on the pot.