For vocalists: an idea for a basic stompbox adapter for microphones

[Processaurus]

Is there an existing project for a box that allows a vocalist to use guitar pedals with their mic, and send that to the PA system?  I know you can use 2 of the transformer adapters, or one of those funky DOD processors, or a lash something together with a little mixer, but I was thinking about crafting a basic, no nonsense, one trick box (maybe you could even velcro pedals on top of it) that has an XLR input, a simple, clean, low noise mic preamp to get the level up to where a guitar signal would be, a 1/4" unbalanced send (out to a pedal), 1/4" return, then a balanced line driver circuit, and an XLR out (to the PA).  Maybe it could even have a PS inside with a couple 9v outputs to power the pedals, or work off of a boss type 9v jack so it could be daisy chained with the pedal(s).

I think this'd prove indispensable once it was being used, because it takes the job of vocal effects out of the sound man's hands and into the band's.  Throw on the delay for big choruses, reverb for normal stuff, always have a compressor on so people can actually understand the lyrics, have it bone dry for in between song banter so you don't sound like you're talking to everyone from Notre Dame...

[soulsonic]

I know this is totally the corny cheapo way of doing it, but we've plugged mics into guitar pedals lots of times with those lame XLR to 1/4" cables that you have to use with junky old PAs that don't have proper mic inputs. The overall signal level seems to be decent... maybe even a little hot.
I do like the idea of your mic interface box - that could be an interesting way of dealing with vocals with band that have alot of effects. The way I've done it in the past with some Industrial groups I've played with is that we'd just plug the mic into a preamp and then chain in a bunch of multi-effector units. The last industrial/electro gig I played, we had the vocals going into a Presonus BlueTube, then DeltaLabs Effectron, then a Digitech S100. The singer would turn the knobs on the Effectron the whole time which makes for some pretty screwed-up effects. It would be much easier to have this sort of arrangement in a stompbox format.

[nappyd]

Hey bro.  Maybe this will inspire you....

I built a "Dub" box for a Singer friend of mine in a touring Reggae / Dub band.   It splits the mic signal with a transformer, hits a momentary switch, sends the signal out to an fx loop when the switch is closed, then an fx return converts ballances the signal to go to the sound system.  I built it with a couple Radio Shack 1/4" Jack-to-A3M XLR Plug Adapter/Transformer  $14.95ea. Model: 274-017 that I had kicking around.  He hits a Line 6 DL4 with it for tap tempo driven analog vibing delay.  It's a pretty cool rig.  I've built stuff like this with Lundahls and Jensens, and well sometimes you can really tell the difference, however in this case the RS cheap tranies sounded just fine.

Whatever you do I recommend splitting the dry signal off first. It makes it a lot easier for the sound guy to deal with.  On another rig I have a mic mute circuit muting the dry send when I want effect only.  Other wise it's always dry from the transformer split, and 100% wet effect on a DI. 

[petemoore]

  I like to support the need for threads like this one.
  Vocals are often the last to get 'the treatment'...
  building a 'matcher' box for impedance issues as a starting point toward tweeked vocal effects I think is an excellent idea.
Then tweeking Jfet/tube/other types of distortiion would be more....common...hopefully, and the ability to get 'something' on the vocals to spice them up would become more common/well known also.
  But just Plugging in the dirtbox can be a neat novelty thing, but soon either feedsback rediculous or other taxing tones or wierdness wear out it's welcome [with me], alot like the Disto-Fuzzers of non-tweeked variety do for guitar use.
  Live Vocals are a whole different horse to try to distort, especially if the vocalist is allowed to hear the PA sound in real time...ie.. Mic > Amp > Speaker > Air > Mic= feedback loop, slamming the signal wave into clipping has the same effect it can on guitar ..sustain/feedback, except there is no string 'guiding' the feedback to any specific pitch so the feedback is uncontrolled...basically mic type feedback becomes harder to avoid when distorting the signal, maybe some type of crossover distortion [which distorts the signal when near 0 amplitude instead of clipping the peaks would be of some good application to vocals?
  Perhaps some kind of phase tricking, so that the distortion wave is of offset phase, so that there is a 'decoupling of the feedback path, or a bit of delay would put the waves enough out of sync so as to prevent sympathetic resonances and interrupt the feedback path.
  My guess is that the 'tone twisters' [my brother used to call effects 'tone twisters'] heard on records of songs which are intended for touring/live performance are the ones which have passed field testing as far as the ability to pull off vocal effects in live situations.
  Some modern tunes have heavily effected vocal sounds [Godsmack for instance], I wonder what/how they're getting that.
  Anyway, for some reason CMOS and Jfet distorters come to mind when dreaming of vocal distortion effects, something with a bit of midrange hump, soft/medium clipping capability.
   

[Mark Hammer]

The SSM2166 (God help me!) is a great candidate for a full-featured "mic strip" with add-ons, since that,s what it was originally designed for.  The amount of "penetration" or "punch" the singer can achieve is controllable via the extremely flexible arrangement for adjusting compression and limiting, and the adjustable downward expansion is great for keeping feedback at bay.  Finally, if all those things were not enough, Q&D compressor users can attest that it's easy on a 9v battery.

Stompbox?  I'm not sure about that.  This seems like more of the sort of thing you build into a shielded plastic box and velcro to the mic stand where a singer can reach over and tweak as needed.

[StephenGiles]

There could be some help on the Rolls site and possibly on the Rane. I have no links with me.

[Mark Hammer]

the Rolls site definitely, since they have a lot of small utility boxes that will run off batteries.

[Pushtone]

Great idea. I support this project each time its brought up.
Love the 9v add ons idea.

And since I'm a PA guy I will have to insist that that at the least
it be equipped with a ground lift switch at pin-1 of the XLR output and a plastic isolated XLR jack.

Of course a transformer would be better.
Then the ground lift becomes a ground re-connect because you'll want it lifted by default with a transformer in line.

Someone please build one already.

[Gus]

I would look for small mixers with phantom power and a microphone input or two.

First a fun thing to do is take a behringer etc mixer with eq a sm57 or what ever microphone turn up the gain to clip the opamps then use the EQ the problem is you need to set the faders low.

Why phantom power?  one can make a phantom powered DI box (even a tube one can be powered from phantom)to plug a guitar or bass or a few DIs to feed the mixer after effects.  then you might have an insert point then you have line ins..... 

Some mixers have built in effects IIRC.

Google ASK etc have fun.

[Mark Hammer]

Youch!!

I think there are two potential paths to pursue here, each of which is valid, but each of which tend to get in the way of the other.  One is sound quality control, and the other is sound effect control.
The first is essentially the case where the band lacks a dedicated sound-person to ride the controls and do adjustment on pre-arranged or visual cue.  There, the presumed unit (whether floor or micstand or table-top mount) serves the function of letting the singer do any "emergency repairs" to the vocal mic signal, and maybe create some special sounds.  I imagine there are many instances where a band lacks the gear to provide individual voice processing (compression, de-essing, etc), and such a strip/box would permit tailoring the sound before it goes to the conventional mixer strip (level, effects send, 3-band EQ, pan, gain trim).

The second case would be some sort of unit that allows for fancy-schmancy processing of voice.  For instance, perhaps a lo-fi "telephone" filter or some sort of voice envelope extraction for controlling other things, and so on.  The assumption is that the signal level leaving that box would be suitable for feeding other pedals, where the output signal on the first one would be suitable for going to a mixer.

[brett]

For instance, perhaps a lo-fi "telephone" filter or some sort of voice envelope extraction for controlling other things, and so on.

By coincidence, I'm working on a Lofo Mofo/one knob fuzz distortion unit and Rebote combination for microphone.  But sometimes I think that a simple carbon mic insert from an old phone would do.  Some time ago I also used a "speaker" from a pair of WWII Headphones for a clapped-out microphone sound.  It was surprisingly good. The "speaker" used a thin, flat steel plate (0.1 mm?) attached directly to a magnet (in a "T" shape).  The magnet sat in the coil.
cheers

[nag hammadi]

is there a layout showing how to go from xlr inputs, adjust impedance for use with common guitar circuits, then adjust imp again and come back out as an xlr?

sloppy description, but you folks know what i mean...