too much treble

[antonis]

 

For 10pF (say) cap, things shouldn't be so tragic.. 

But, generaly speaking, I DO deserve a good hand slapping..

[Harry Muff]

supposed to be a low pass or high cut - we shall see when i go test on BB ..i have a few ideas 

[antonis]

It supposed to be "isolated" from op-amp output..
(op-amps don't like driving capacitive loads ..)

[PRR]

...the cap marked "b" - is that not now a cap connected to the oppie output and ground, and therefore not allowed?

"Connected" through >1k resistance. No problem.

[Harry Muff]

...the cap marked "b" - is that not now a cap connected to the oppie output and ground, and therefore not allowed?

"Connected" through >1k resistance. No problem.

it was a 10nf as part of the RC network between 1-6  i was going to put a lpf there but im guessing you guys say it won work? i will be BB tonight was i get up and get going ( working two jobs is killing me) I have a book im reading but im still stuck in chapter 1-2 lol ..i would gibe my left arm for my digital one and EE 101 books I sold back to the book store for quick cash.. they are invaluable now . i had this thing working at one point but sounded like an ice pick stabbing the brain and ear drum

this is where I left off last night and what I will BB first off after coffee and some fifa pro clubs lol - antonis why did you mod a 470nF poly cap in between output A and non inverting pin 6? so running a poly cap to ground wont bleed ut the treble? and what is the 1.5uF cap you added in place of my 47nF on the gain ? was it poly cap or electro ?? my fault for not susing proper schematic smbols and being clearer in drawings. I just broke out the drawing kit a few days ago. will take a minute to get myself neater with stuff

[PRR]

> EE 101 books I sold back to the book store for quick cash.. they are invaluable now .

Most textbooks more than a few classes old now sell for $5-$30 on eBay and ABE.com

[antonis]

antonis why did you mod a 470nF poly cap in between output A and non inverting pin 6?

To prevent DC from output A going into pin 6..
(it could be omited, together with Vref wire, in case of output A going to pin 5..)

and what is the 1.5uF cap you added in place of my 47nF on the gain ?

47nF & 1k resistor form a HPF of about 3.4kHz cut-off frequency which, IMHO, is high enough for this particular stage..
1.5μF lowers cut-off frequency down to 106Hz..
Of course, you can play with cap value to bring particular cut-off frequency to your taste..

P.S.
Just a modified schematic making clear (I hope.. ) the usual filters around an op-amp stage..



edit: Forgot to draw output cap (just right after junction of pin 6 & NFB loop wiring) which forms another HPF with Load impedance.. 

[duck_arse]

...the cap marked "b" - is that not now a cap connected to the oppie output and ground, and therefore not allowed?

"Connected" through >1k resistance. No problem.

those two caps on your circuit dia around the second opamp - 2.2pF? 2.2nF? 2.2uF? you need to show the multiplier every single time, or the number [2.2] is rendered meaningless.

a slap for antonis.

and a hmmm ..... for Paul's "through >1k resistance."

[edit :]

[Harry Muff]

i was off in my drawings had to change stuff but its working and sounds like an ice pick and ll distortion lol

https://www.wamplerpedals.com/blog/uncategorized/2020/05/how-to-design-a-basic-overdrive-pedal-circuit/

I started with wampler design and tried to go for my own ..not working ..but I  see his LPF is very simple off the output..will that work i guess? i have my pups in my guitar wired similar so I can have a tone knob on the bridge

i think im going to give up for a minute, come back to it later, and just clone a timothy which is similar but tim has vref on the opposite pins?


ducks arse, using the FC formula I got a 001 uF and a 39k (no more 25k and 2.2) to give me around 4kH ..i really dont now what that mean but should be more mid rangy?  or does my corner start at 4k and can be adjusted? i wish I had an oscope and a signal generator  to mess with

antonis, are you one of the blokes from jam pedals ?