https://www.google.co.in/search?biw...3.4.275....0.sgAZZgjwMX8#imgrc=kif2vpqE6F0XQM:

i made and pre amp using the above schematic but the problem is too much ground noise //buzz//hum//distortion even with connecting the output to the laptop and problem increases even more when i put my laptop on charging.
is there any one here who can make this above schematic noise free distortion free make its sound clean and loud ,because i search many websites but did not get any solid solution for that you guys are my last hope pls send the modifies schematic of mine

 

Hello,

What do you use to power the preamp?
Perhaps the noise is coming from the powersupply.

Bertus

 

usb port of pc

 

here is the audacity result

 

Hello,

What do you use to power the preamp?
Perhaps the noise is coming from the powersupply.

Bertus

Sir pls help me out

 

hi,
I would add some power line decoupling for starters, the USB power is noisy.
E

 

hi,
I would add some power line decoupling for starters, the USB power is noisy.
E
View attachment 161986

will this modified schematic remove all the noise????

 

Hello,

Here is some additional decoupling for the mic itself:



Bertus

 

hi,
It is something I would always have in a preamp, especially a USB powered version.
Decoupling is standard practice in most analog projects.
E

 

Hello,

Have a look at the schematic in the link:
http://freeelectricalsandtools.blogspot.com/2009/08/computer-microphone-circuit.html#links



It uses the power from the mic input of the soundcard.
It shows multiple decoupling as @ericgibbs and I showed you.

Bertus

 

will this modified schematic remove all the noise?

It should significantly help, but no one can predict if it will remove "all" of the noise, since there could be other noise sources we aren't aware of.

 

For a simple test, use a 9V battery for the power supply.

 

It should significantly help, but no one can predict if it will remove "all" of the noise, since there could be other noise sources we aren't aware of.

If you hv anything in your mind that can be added to my schematic so that it can give a clean signal pls do share the modified schematic of mine
Thank you

 

For a simple test, use a 9V battery for the power supply.

I tested with 9v battery but same is happening signal is very good but the noise is too much and very annoying when more when i use my amp in laptop on charging mode
Pls try my schematic on your breadboard and try to find a permanent solution for this problem

 

The problem is not with the circuit. The noise is AC pickup. You need to shield the entire circuit and use a shielded cable going into the laptop (and use a 9V battery).

 

Hello,

Have a look at the schematic in the link:
http://freeelectricalsandtools.blogspot.com/2009/08/computer-microphone-circuit.html#links

View attachment 161989

It uses the power from the mic input of the soundcard.
It shows multiple decoupling as @ericgibbs and I showed you.

Bertus

Thank for your active support Bertus Sir i will try every solution given by you and let you know mean while i am requesting you to try schematic setup on your breadboard if you find that noise is gone after your modifications do share that fina schematic with the change

 

hi,
It is something I would always have in a preamp, especially a USB powered version.
Decoupling is standard practice in most analog projects.
E

Thank you ericgibbs sir i will try the solution given by you and let you know

 

The problem is not with the circuit. The noise is AC pickup. You need to shield the entire circuit and use a shielded cable going into the laptop (and use a 9V battery).

I am requesting you to try the schematic on your bread board and share the corrected schematic

 

Hi Kumar

I don't think they will do it for the fact that they have solved your question supplying a working circuit,
therefore you are expected to test it and whether report back that it works, question solved, nice, or
it doesn't work yet, the reasons being this and that ..

If you have access to a college or uni electronics lab, could you just get the components and build the circuit?

do you have a breadboard?

regards

John BG

 

Hi Kumar

I don't think they will do it for the fact that they have solved your question supplying a working circuit,
therefore you are expected to test it and whether report back that it works, question solved, nice, or
it doesn't work yet, the reasons being this and that ..

If you have access to a college or uni electronics lab, could you just get the components and build the circuit?

do you have a breadboard?

regards

John BG

Yes I have bread board do have any solution ???????
actually i dont hv coz i am not a engineering student
i am commerce graduate in accountancy
this project i took for my self to make a good preamp for my laptop