Dynamic Mic impedance changer?

[simon111]

Hi,

I am after a circuit that will allow me to interface a dynamic microphone into a standard stomp box pedal. As plugging it directly in doesn't achieve a desirable sound.

Also I would liek the option to convert the output of the FX pedal to line level use (i.e. a PA as well as standard guitar map)
Signal chain.....

MICROPHONE > FX PEDAL > AMP (guita amp) or PA (line level)


I am guessing an impedance canger is needed, so:

MICROPHONE > IMPEDANCE CHANGER > FX PEDAL > AMP

Any help would be great guys.

Simon.

[Ripthorn]

The mic has a very low output impedance, so it should still be able to drive a high input impedance device like a stompbox, you probably just need a signal booster, seeing as how the microphone's signal is extremely weak compared to a guitar's output (for most pickups, at least).  The big thing is changing the impedance of the fx out, which will most likely require a transformer.  You need to know your fx output impedance, and if you want to run it with a mic-type impedance, you should shoot for a 600 ohm secondary.  It's a topic that has come up before, I believe, and it is always a little more complicated than some think just because the level as well as the impedance depend not only on the mic, but on the specific circuit being used.  I'm not saying it can't be done, I'm just saying that you have to have a very well defined idea of what you are trying to accomplish.  Maybe a little more info and we might be able to get a more solid idea of what to do.

[wavley]

I'm guessing that when you're plugging a mic into a stompbox that we aren't worried about fidelity so the Rat Shack XLR to 1/4" impedance matcher will most likely work unless it's because the mic doesn't have enough output in which case some sort of preamp like an ART Tube MP would do you.

[trixdropd]

I'm guessing that when you're plugging a mic into a stompbox that we aren't worried about fidelity so the Rat Shack XLR to 1/4" impedance matcher will most likely work unless it's because the mic doesn't have enough output in which case some sort of preamp like an ART Tube MP would do you.

Your best bet would be running the pedal as an insert at front of house on the mic's channel. What you could do is build a true bypass looper for the pedal with a relay that lets it be controlled remotely. Then, run your footswitch into the snake from the stage back to Foh so you still turn it on and off. This would be a pain if you don't travel with your own Pa setup and sound guy.

The cheapest most easy way to do this is buying a small mixer like a behringer 4 channel or something. Put the pedal in the mic channels insert. So you take the mic, plug it into your mixer, use the insert, and use the main out to feed where your mic normally would be plugged in.   otherwise, you need a mic pre, impedence adapter,and a direct box. maybe a small pre with an insert would be the ticket as well....   

[wavley]

I'm guessing that when you're plugging a mic into a stompbox that we aren't worried about fidelity so the Rat Shack XLR to 1/4" impedance matcher will most likely work unless it's because the mic doesn't have enough output in which case some sort of preamp like an ART Tube MP would do you.

Your best bet would be running the pedal as an insert at front of house on the mic's channel. What you could do is build a true bypass looper for the pedal with a relay that lets it be controlled remotely. Then, run your footswitch into the snake from the stage back to Foh so you still turn it on and off. This would be a pain if you don't travel with your own Pa setup and sound guy.

The cheapest most easy way to do this is buying a small mixer like a behringer 4 channel or something. Put the pedal in the mic channels insert. So you take the mic, plug it into your mixer, use the insert, and use the main out to feed where your mic normally would be plugged in.   otherwise, you need a mic pre, impedence adapter,and a direct box. maybe a small pre with an insert would be the ticket as well....   

This is certainly the best way to do it.

Check out the recent article about The Faint in mix magazine where he talks about using a distortion pedal from wal mart this way