# Plug Mic to AUX in on receiver?



## BlackOmega

Hey guys, I'm trying to hook up a microphone and an iPod to a receiver. Problem is there is no MIC input, only an AUX input (RCA connectors).

Can I simply make a 1/8" (3.5mm) to RCA cable and plug it in? And if I do it that way will they mic need to be powered? I'm assuming it would work with an iPod since it provides it's own power.

Let me know if I'm on the right track or am I way off quilter.


----------



## JVene

The output from a microphone is generally to low a signal to work in an "Aux" input. The latter is referred to as "line level", about 1 volt, whereas the microphone may be 1/10th that.

You need a microphone pre-amp to do it.

You can make one out of an operational amplifier if you can handle a soldering iron, about 6 parts and a battery (or two) for power.

Otherwise, you'll have to arrange for one somehow.


----------



## ZHoob2004

microphones need power applied to them in order for there to be any sort of signal. you need a microphone input or, as said above, microphone preamp (although I'm not sure that's what they're called)


----------



## JVene

Quote:

microphone preamp (although I'm not sure that's what they're called)
Yep....always has been.

Though....often hyphenated...pre-amp


----------



## BlackOmega

Quote:


Originally Posted by *JVene* 
The output from a microphone is generally to low a signal to work in an "Aux" input. The latter is referred to as "line level", about 1 volt, whereas the microphone may be 1/10th that.

You need a microphone pre-amp to do it.

You can make one out of an operational amplifier if you can handle a soldering iron, about 6 parts and a battery (or two) for power.

Otherwise, you'll have to arrange for one somehow.

Thanks for the input. Do you have any links or guides to making one? I'm pretty handy with a soldering iron so that's not an issue.

Quote:


Originally Posted by *ZHoob2004* 
microphones need power applied to them in order for there to be any sort of signal. you need a microphone input or, as said above, microphone preamp (although I'm not sure that's what they're called)

Yeah they're called mic pre-amplifiers.

Arg, what is it with all of these new electronics not having mic in's.


----------



## JVene

Here are some options

http://www.reconnsworld.com/audio_simplepreamp.html

http://www.zen22142.zen.co.uk/Circui...o/compmic.html

http://www.reconnsworld.com/audio_electretamp.html

http://www.zen22142.zen.co.uk/Circui.../lf071_mic.htm

A couple are based on simple transistor class A amplifiers.

The last one is an op amp based circuit, and any op-amp IC will do, the TL07n series come in 1, 2 and 4 amp per package chips and are widely available, the OPA371 is high performance, the NE5534 is very good (old design, but still top notch).

There's one that lists the 741 op amp...don't use that. The circuit can use nearly any op amp, but the old 741 is outdated and tough to use (might not even be on the shelf anymore, which would be good).


----------

