NPN Boost Circuit Help (From Wampler Book)

[SpringbokUK]

Haha I bet. Crazy how successful he got.

Ahhh okay cool. Is that regardless of what the lugs are connected to? In this case the output cap from q1 goes to lug 3, which is then connected to one leg of the cap and onto the other part of the circuit. The other leg of the cap is connected to lug 2 and lug 1 to ground. So as I turn it ccw the signal or frequencies that's getting passed through the cap goes to ground and that'll be the low frequencies?

[pinkjimiphoton]

that makes it so as you turn it down, it won't lose its sizzle. it seems like a treble "boost" but its actually a bass "cut". keeps it from mudding up as ya turn it down. makes no diff beyond a certain point, as the bass will be as "cut" as it gets by half the rotation of the pot. i think.

[SpringbokUK]

I have a lot to learn haha

So let's say lug 3 is connected to the cap and the cap is connected to lug 2 but also to the following part of the circuit and lug 1 Is still ground. Is that the same? The only difference is that one leg of the cap is connected to lug 3 and the other leg is connected to lug 2 AND goes onto the remaining circuit whereas the other just connects to lug 2 and lug 3. Both are shown in the book and it describes as the same.

I'm guessing a cap in series with a variable resistor is a low pass filter? But also a resistor going into cap into ground is an LPF too? And in reverse it would be HPF. I get it I think its just I'm always like "but why". Maybe I should just not even go there, accept it and move on haha.

Damn there's so many variations with these things. Confusion is at max. Maybe I should revisit in the morning.

[pinkjimiphoton]

a cap and resistor in parallel are a hi pass filter

a cap and a resistor in series is a low pass filter.

hi pass cuts lows
low pass cuts highs.

you'll get it. no worries.

[SpringbokUK]

But the if the resistor and cap are in series doesn't the cap have to go to ground to be low pass?

[pinkjimiphoton]

yes. doesn't matter which order, really.

[antonis]

I think your last post could confuse Liam, Jim..

But I'm happy you made things clear between BOOST & FUZZ ..!!   

[SpringbokUK]

Haha nah I aint confused.. I think I got it. The order of the resistor and cap doesn't matter, so long as that cap goes to ground its LPF. And if that ain't it then I am definitely confused

[pinkjimiphoton]

mebbe this will help.

low pass filters usually run in parallel with the signal, and often terminate in one end of the cap to ground.

high pass filters run in series with the signal.

[SpringbokUK]

Woah. So LPFs are parallel to the signal but the cap is in series with a resistor and HPFs are in series with the signal but the resistor is parallel with the cap. I can't find a fitting emoji so just imagine that the top of my head just blew open and loads of steam is coming out.

okay so the 1st picture from the right the variable low pass.. what if lug 1 was going to GND as well? obviously the connection that goes to in also goes to say the next clipping stage...

I'm so sorry if I'm being aggravating haha.

[pinkjimiphoton]

Woah. So LPFs are parallel to the signal but the cap is in series with a resistor and HPFs are in series with the signal but the resistor is parallel with the cap. I can't find a fitting emoji so just imagine that the top of my head just blew open and loads of steam is coming out.

yes. at first i looked at it funny, but yep, thats basically it.

okay so the 1st picture from the right the variable low pass.. what if lug 1 was going to GND as well? obviously the connection that goes to in also goes to say the next clipping stage...

if it were going to ground as well, it would cut lows as it reduces volume, just like the question you asked about. mainly it would work as a volume control, cuz you'd shunt signal to ground.
the first half of the rotation would cut bass and volume, second half cut volume to 00

I'm so sorry if I'm being aggravating haha.

boy, i say, i say,boy,  stop tryin to troll, me, son, and pay attention, now!!





lol just kidding, no problem.

[SpringbokUK]

Hahaha, right I think I get it. Gotta apply this new found knowledge..
Hopefully we'll see a new revised Wampler book before long!

[ElectricDruid]

Sorry, but I really don't think that diagram is very helpful. The last case doesn't even have an output on it! That level of sloppy makes me suspicious...
All of them ignore whatever comes before and after, which is going to have a big influence in practical cases. Some of those filters seem to *assume* a load resistance from output to ground, but don't state that or characterise it in any way. But others just don't make sense. I think it confuses much more than it clarifies. Whilst some of those arrangements might work in the stated way in certain situations, you'll only understand why that's the case if you understand the basics.

The series on "passive filters" here is more like it (scroll down a bit):

https://www.electronics-tutorials.ws/category/filter

HTH,
Tom

[pinkjimiphoton]

well, it was meant to illustrate a point to him tom. is there an output on a tone control in a guitar? nope.
its in parallel with the signal.
your link is indeed way more helpful, but i was trying to answer the questions he'd asked me about things, so he could get a quickl idea of a couple examples, it was never meant to be a tutorial, bro.

in the end...  make it easier for him than i did.

define a couple simple lo pass and hi pass filters. no values necessary, just the basic way they're wired.

i get your point, but sheesh, dude... lmao

level of sloppy? well, by all means, please take the time to make some simple paint graphic to illustrate the basic concepts, please, as explained, if ya read the shit back and forth, one way of doing a simple low pass filter is a variable resistance in series with a cap to ground. in parallel with the signal. so no output in that case. think about it.

glad ya chimed in by all means, but.....

for the info on passive band pass filters, if ya read the stuff at the link ya posted, you may be surprised to see it says the same @#$%ing thing.

example

https://www.electronics-tutorials.ws/filter/filter_4.html



lets see... resistor in series with a cap. and a cap and resistor in parallel.

hi pass filter.... a cap feeding a resistor to ground....


lo pass filter....  resistor with cap to ground



pretty much the same shit i said, worded differently and drawn differently.

but still the same concepts.  cap and resistor in parallel in series with signal is a hi pass filter.
cap and resistor in series in parallel with signal is a lo pass filter.

sorry for oversimplifying this too drastically 



no output.



please, by all means, show us how to do it right.

[pinkjimiphoton]

ya'll may find this useful and helpful hopefully

http://sim.okawa-denshi.jp/en/OPtazyuLowkeisan.htm

[ElectricDruid]

Sorry Jimi, I wasn't meaning to tread on your toes.

And yeah, I agree - ultimately these *are* all the same thing, just explained differently. But that's kind of the point; some ways of explaining stuff make it make a lot more sense than other ways.

Like "no output"? Really? There's *always* an output. Even on that guitar tone control you mentioned. After all, you tap the signal from somewhere, and that place where you tap it from - that's your output. But you know that already, and again we're just explaining things differently. But that's cool, I've got no problem with that.

Sorry for getting in the way - that wasn't my intention. Carry on as you were!

Tom

PS: The okawa-denshi link is great. Everyone should know about that site.

[pinkjimiphoton]

Sorry Jimi, I wasn't meaning to tread on your toes.

And yeah, I agree - ultimately these *are* all the same thing, just explained differently. But that's kind of the point; some ways of explaining stuff make it make a lot more sense than other ways.

Like "no output"? Really? There's *always* an output. Even on that guitar tone control you mentioned. After all, you tap the signal from somewhere, and that place where you tap it from - that's your output. But you know that already, and again we're just explaining things differently. But that's cool, I've got no problem with that.

Sorry for getting in the way - that wasn't my intention. Carry on as you were!

Tom

PS: The okawa-denshi link is great. Everyone should know about that site.

if any sorrys are needed, its me for seeming pissy-ly amused. more amused than upset.

well, there's no output necessary on that tone control, cuz the input is also the output.. its in parallel with the signal, so the output is actually GROUND,  as shown.

somewhere i think i mentioned it taps off the signal, but i could be wrong. having to give up caffiene and alcohol haven't done me any favors tom!! lol

thanks for sounding off, i really like it better when people who actually understand/know this stuff try and help the new guys, remember, i'm a fuzzbox guy whom's specialty is letting magick smoke out.

so far, i know absotively nada about active filters, etc... i still take the low road with the stuff i do, but i'm TRYING to distort the sound, so... its more like being a monkey with a breadboard.

please teach us more bro, if ya got it in ya, cuz i know i for one, am ALWAYS hungering for new learning and info!
peace, brother!


PjP