connecting a mike to my stomps

Started by aidoru1, March 14, 2005, 09:13:42 AM

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aidoru1

I need to use my stompboxes (distortion devices, delay, tremolo) with a dynamic microphone in input. The output from efx chain will go to a PA. Will I encounter impedance problems, noise, hum etc...If so, how can I connect all this stuff in the best way possibly without loss of signal quality? (I can get DI boxes and many other PA live equipement if needed)
Thank you!

Mark Hammer

Dynamic microphones have outputs many many times lower in amplitude than a guitar pickup.  This means that in order to use your effects pedals as if you were feeding them a guitar signal, you will need to bring the mic signal up to the same level with a mic preamp.

I can hear you say "But I am not trying to use voice with a fuzz box, why do I need to bring the level up so high?".

Because EVERY pedal and cable contributes noise.  The higher your signal is (up to a certain point...you DO need headroom, after all), the better the signal to noise ratio (In fact, many pedals could probably perform a little better in that way if the guitar signal were hotter, too).  Also, note that the impedance of most dynamic microphones is very low compared to guitars.  A mic preamp which accepts such low impedances will be necessary to provide better matching.

scottosan

Quote from: aidoru1I need to use my stompboxes (distortion devices, delay, tremolo) with a dynamic microphone in input. The output from efx chain will go to a PA. Will I encounter impedance problems, noise, hum etc...If so, how can I connect all this stuff in the best way possibly without loss of signal quality? (I can get DI boxes and many other PA live equipement if needed)
Thank you!
Why would you want to do this?

Bagge

Wouldn't it be possible to run the effects chain through aux send/return, or insert of the mixer instead? I realize you will need long cables if you need to activate the stompboxes on stage. But this way would get you around impedance problems. Otherwise you would need a preamp before the effects chain as Mark Hammer stated.

octafish

Watch the unity gain. I tried to mic an acoustic guitar through a simple booster, (like a simple mic preamp) into a fuzz box, (can't remember which one) into an amp. Couldn't do it in the room I was in, way too much feedback from natural reverb. Tried the PA instead but then I couldn't have any foldback at all. I have a friend who has done a similar thing playing harmonica, he used a harp mic and a BMP, not sure if he used a preamp it might not be needed with his mic, but he had this magic box called a Noise Gate that cut all the microphonic feedback. He could really blast it out and never had a squeal.
Shoot straight you bastards. Don't make a mess of it. -Last words of Breaker Morant

KORGULL

I've always just used a mic impedance matching transformer plug. It accepts your XLR mic cable on one end and has a 1/4" (6.5mm) plug on the other. Takes your mic's low Z signal and makes it high Z, like a guitar.
Works fine with delay, tremolo, chorus, etc.. but as previously mentioned you will need a noise gate for distortion/boost type FX - unless you like squealing microphonic feedback. You might be O.K. (without a noise gate)at low volume with the gain backed off, standing as far away as possible and not facing the speakers.