Sallen Key Low Pass Filter, bandpass filter

[Maglatron]

nope it's not having it, still topping out!!

 

[bertus]

Hello,

Did you also change R20 and R21?
What is the complete schematic now?

Bertus

 

[Maglatron]

this shows the place where I put the, out of the filters

this shows the ammended resistors

 

[Maglatron]

complete circuits yes changed the resistor R20 and R21!!
7000Hz
45Hz

 

[bertus]

Hello,

I see that C12 is 0,1 uF. Change that to 10 uF.
This will give the 45 Hz a higher throughput.

Bertus

 

[Maglatron]

Hello,

I see that C12 is 0,1 uF. Change that to 10 uF.
This will give the 45 Hz a higher throughput.

Bertus

What will higher throughput do and how does it help with the 7000Hz filter? thanks, it hasn't seemed to have done anything noticable!

 

[bertus]

Hello,

The impedance of the 0.1 uF capacitor is to high for the 45 Hz.
At 7000 Hz the impedance is low enough to pass the signal.

Read the AC section of this wiki page:

Capacitor - Wikipedia

en.wikipedia.org

Bertus

 

[Maglatron]

nope not yet still tops out I hope you have not exhausted your ideas thanks again for helping this is the last part if we get this running for the lowest frequency and the highest frequency then the middle frequencies should work.

 

[Maglatron]

did you run the sim I uploaded the sound file in the form of .txt and the .asc file for the 7000Hz

 

[bertus]

Hello,

Is the 45 Hz now also clipping?
The gain should be highr at 45 Hz.

Bertus

 

[Maglatron]

No but the highest peak now reaches 9 volt instead of the prefered 8.4 so it has adjusted it slightly, I think we're getting somewhere!
I don't know if this helps but I want to remind you that the circuit worked as desired when R13 was 4.7k and R23 was set to 1k but thats not acceptable because I want the one pre-amp and amp for all of the filters!

 

[Maglatron]

It's not even dipping look at the time on the 45Hz and when the peaks and troughs there are no troughs on the 7000Hz analysis

 

[bertus]

Hello,

I did run the 7000 Hz with changed parameters:




Sorry for the firefox overlay.

Bertus

 

[Maglatron]

Sorry my mistake the two audio files are different for the 45Hz and 7000Hz, they are not related in any way!

 

[Maglatron]

which parameters? I see R13 and R23 are changed

 

[bertus]

Hello,

The 7000 Hz file seems to be an older version, I needed to change the following:

C12 = 10 uF
R23 = 15 K
R13 = 27 K
C15 = 10 uF
R20 = 100 K
R21 = 500 K
C17 = 10 uF

Bertus

 

[Maglatron]

simulating this looks good! so now will this pre-amp and amp be good for all the frequency filter I will simulate one in the middle of 45Hz and 7000Hz and see what it's saying thank you very muchly

 

[Maglatron]

I'm going to let it run its course back tomorrow!

 

[Maglatron]

so it ran and it's really good for the 7000Hz it reaches 8.4v on the envelope detector But for the 45Hz and the 8th filter on the list (474Hz) they both only reach to a maximum of nearly 6.1 volts but at least now they are all showing on the chart now!!! definatly getting somewhere!!

 

[Maglatron]

474Hz again the txt file is the .wav