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Inline PC Microphone Amplifier
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Please be positive and constructive with your questions and comments.

Inline PC Microphone Amplifier

by Gibson on Mon Sep 27, 2010 12:00 am

Hi all,

I am considering making a small microphone amplifier for my PC headset. At present it appears the microphone is not providing enough volume, and I am forced to increase the volume in software which I would consider less ideal than boosting the original analog signal. Nonetheless, I have a few things to test before I permanently install an amplifier on the mic line, however I would still like to create one simply because the idea intrigues me.

My thoughts at the moment are a low-power Op Amp with mic in and mic out, with volume control. There are some other things I would like to try also like signal filters or variable gain however they will be more for experimentation and are out of the scope of this post. My main concerns at the moment are:

Power - I believe a PC mic-in can provide a 'bias voltage' to provide power to active microphone systems. I have read also that this can sometimes be superimposed with the line signal. Does anyone know whether it would be plausible to power a single low-power op-amp from this voltage or am I best just to use a couple of AA's or a 9V to power the amp?

Signal - As above, if signal is combined with a DC bias voltage I imagine I would use high/low pass filters to separate the two, however I am unsure what sort of configuration I would use.

Impedence - A high input impedence and low output impedence are obvious. As far as what sort of impedences I should be looking for, can anyone provide some insight?

Any advice would be much appreciated.

Regards,

Gibson.
Gibson
 
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Re: Inline PC Microphone Amplifier

by richms on Mon Sep 27, 2010 12:41 am

Have you checked that you have the correct drivers for the audio chip in the computer installed?

Once I got the correct realtek drivers, I got another tray application that had a microphone boost slider in it that would add 10,20, or 30dB to the mic input.

richms
 
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Re: Inline PC Microphone Amplifier

by Gibson on Mon Sep 27, 2010 1:16 am

Thanks for your advice richms,

the drivers are correct. The slider that you speak of is the software volume control I mentioned in my original post. There are a number of factors that could be affecting my setup including a KVM switch that I use to control a number of PC's that also has audio switching functionality. I am not interested in the IT side of the issue however, as I have that covered. My interest is more oriented toward building the amplifier as I am a whole lot newer to electronics than I am computers.

Thanks :D
Gibson
 
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Re: Inline PC Microphone Amplifier

by neutron spin on Mon Sep 27, 2010 11:02 pm

Check this out...it's $22
http://www.google.com/products/catalog? ... 8wIwADgA#p

It's for headphones but it may work for your microphone as an aux amp....If you want something homebrew use a TL082 op-amp...easy to do ....
neutron spin
 
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Please be positive and constructive with your questions and comments.