I am using a Logitech/Labtech USB microphone which is doing an okay
job but could benefit from some more gain. I don't want to touch their
ADC and USB circuit but would prefer adding something in-line. Given
that their 2-wire electret micro is powered by 2.5v on the signal line
what would be a simple way to say double the signal seen by the
circuit downstream ?

<g...@gmail.com> wrote in message
news:1...@e65g2000hsc.googlegroups.com...
> I am using a Logitech/Labtech USB microphone which is doing an okay
> job but could benefit from some more gain. I don't want to touch their
> ADC and USB circuit but would prefer adding something in-line. Given
> that their 2-wire electret micro is powered by 2.5v on the signal line
> what would be a simple way to say double the signal seen by the
> circuit downstream ?
>

Use an opamp configured to provide a gain of 2.

The o-l-d LM1458 dual opamp would work fine
and it runs on a single ended supply.

Lord Garth wrote:

> <g...@gmail.com> wrote
>
> > I am using a Logitech/Labtech USB microphone which is doing an okay
> > job but could benefit from some more gain. I don't want to touch their
> > ADC and USB circuit but would prefer adding something in-line. Given
> > that their 2-wire electret micro is powered by 2.5v on the signal line
> > what would be a simple way to say double the signal seen by the
> > circuit downstream ?
> >
>
> Use an opamp configured to provide a gain of 2.
>
> The o-l-d LM1458 dual opamp would work fine
> and it runs on a single ended supply.

It's doesn't run on 2.5V though does it ?

A TLC271 might be ok.

Graham