Newsgroups: rec.audio.tech
Subject: Re: converting unbalanced line output to unbalanced mic input
References: <[email protected]>
"seismo"  writes:

> I have a single channel application (in home paging) where for part of my
> subsystem I need to convert an unbalanced line level output to an unbalanced
> mic level input.

Try my circuit design shown at
http://www.hut.fi/Misc/Electronics/circuits/line_to_mic.html

If you get any 50/60 Hz noise problems, put an audio isolation transformer
to teihter input or output side of my circuit.
 
> What would people recommend as a cost effective solution to this problem?  

If you know some basic electronics and know how to solder (or know
a friend who can do this for you chealpy), I would recommend to
try my circuit. Building it by a compentent person with components
takes definately less time than trying to find anything ready
made for this application.

> I spoke with the people at RDL, and they suggested the ST-MX2 universal audio
> mixer. It seems like this piece has more capability than I need, and I only
> wish to pay for what I need.  

This solution could be quite universal, but is definately very
much overkill for this application.

> I know something like this could probably be
> made easily out of piece parts, but I'd rather spend a small amount of money
> rather than take on a new project (I already have LOTS of those).

This can be easily done using few parts as shown. You do not need
to start any lengthy new project for this, because this kind of simple
circuit can be constructed faster than writing any project plan for this.

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/