true bypass effect loop with xlr's

[harrisxr650]

hey guys happy new year
I'm in search for a true bypass pedal looper for using it with vocals and run in parallel a rack effect (lexicon mx200) to be able to use in real time onstage.
I need xlr input and output so i can plug mic and then send it to the mixer and normal 1/4 TRS for send/return as well as send/return pots for more control ( i guess thats not much difficult at all)
so far i'm a bit confused regarding wiring of the input/output xlr to the switch ( 3pdt?) and to the send/return jacks. Anyone can shed some light with a diagram or something?
thanks

[dwmorrin]

hey guys happy new year
I'm in search for a true bypass pedal looper for using it with vocals and run in parallel a rack effect (lexicon mx200) to be able to use in real time onstage.

What does "run in parallel" mean regarding the loop box? True bypass implies you'd be switching to an effect loop in series with the mic signal. If it's in parallel then you wouldn't want true bypass.

I need xlr input and output so i can plug mic and then send it to the mixer and normal 1/4 TRS for send/return as well as send/return pots for more control ( i guess thats not much difficult at all)
so far i'm a bit confused regarding wiring of the input/output xlr to the switch ( 3pdt?) and to the send/return jacks. Anyone can shed some light with a diagram or something?
thanks

For generic loop box diagrams:
http://www.beavisaudio.com/techpages/PedalHacker/
For the actual switching, you should clarify if you want the series type switching in the beavis diagrams, or a parallel scheme, which will be less complex.

Did you check out the Lexicon MX200 manual? The unit has a bypass footswitch, and page 7 of the manual (http://www.tpa-az.com/downloads/MX200Manual_B.pdf) appears to have the setup you desire.
Did you not want a mini mixer at your feet/nearby?

[harrisxr650]

i was looking at Beavis "True Bypass Loop with LED Indicator and a Volume Control" before and i though that this could work for onstage use which our singer wants (i'm a bit newbie with vocal equip and electronics so forgive my silly questions) what he want is to have the mic signal direct to the console and have the lexicon near him and play with the effects (he wants delays and reverbs added parallel to his signal...). is this doable with something like that or we have to buy a small mixer? to put near him?
thanks

[dwmorrin]

In my experience, it's best to assume that the sound guy is not going to be very helpful in achieving an unusual setup (some might, but plan for the worst), so it's best to offer the sound guy 1 jack to plug his "vocal mic" XLR into.
Normally, his "vocal mic" XLR goes into the vocal mic. Now, it should be plugging into a "mix out" jack on whatever box you end up using. Either way, sound guy is still only dealing with 1 cable for the vocals.

The simplest solution is to use a mini mixer on stage. Vocals go into mixer, use lexicon in a send and return channel, sound guy gets the mixer output as "vocals."
Sound guy will only be able to turn up and down whatever you send him.
The singer will be responsible for getting the gain correct on the mic, and the levels for the effect.

Alternatively, you could send the mic signal all the way up to the live console, then request 1 line sent BACK to the stage (this may require changing the patching at the console, which not every sound guy will be willing or able to do) which gets plugged into lexicon, and then the return signal gets DI'd back up to the console.
The Lexicon has input, output, and bypass controls on it, so no additional box is necessary.

If you go for the second option, I would advise contacting the venue well ahead of time, get in touch with the sound guy, and/or address this issue as quickly as possible upon arrival at the venue. It may seem like overkill, and the response will vary from venue to venue, but good communication with the sound guy is the only way to ensure a plan like actually works when it's showtime.

Typical problem with the second setup is, now you have 2 vocal lines. What if there's no effect for the 1st song, so the channel is turned down... then 2nd song kicks in, effects on the vocal get sent, but sound guy doesn't turn up return channel...
The sound guy might forget about the 2 channel, or he may mix it too low, too high... you might be tempted to have him follow your setlist... Much easier is to control everything on stage unless you have the budget for a dedicated sound guy for the band.

[harrisxr650]

..or having presets saved on the lexicon and give a note to the sound guy which one is for every song and follow the "alternative way" ...only difference is that the effect is controled by the sound man near the console... to be honest thats the best (logical) solution for me if you trust the sound man will do his job correctly as you said...
the simple solution is simple enough and i guess a small 4channel mixer will do the job? correct me if i'm wrong
thanks again

[dwmorrin]

You need 1 mic input (first channel), 1 send to the lex (a send out), 1 return from the lex (the second channel), and an output for the venue.

A 2 channel mixer is all I see as being needed.
Not a terribly difficult DIY job, but a there's a lot of cheap and cheerful mixers out there that should make you happy.
A male XLR out would be extra nice, as this is what the vocal->console XLR cable is looking for.
Probably not a feature on most cheap mixers, but you could DIY such a thing, or keep a 1/4" to XLR male adapter/patch cable handy just in case.

[harrisxr650]

Great, thanks for the advice, i think we do have a spare 4channel mixer, dunno if its working though...
is there any diagram for a diy construction? since i got in the trouble of looking at it i would like to try and build something that will do the work ( just for the fun of it)
again thanks for your help cheers!

[phatt]

Already been mentioned but
1/ You don't need true bypass if it's in parallel.

2/ You just need a mixer with an *Insert point* which comes after the mixer preamp (on most consoles).

Even cheaper mixers often have *Insert Points* which is a series connection and breaks the signal path,,,
OR

Find a small mixer which has an *EFX send / return* which will simplify the whole thing.
That may work out faster and cheaper in the long run.
As has been said; Send the mix out from that small mixer back to main desk for FOH mix.
Phil.

[commathe]

I'm not sure if it was mentioned but an XLR output is balanced. It has three pins. One of the pins is "in-phase" while another pin is "out-of-phase" (180 degrees/upside down version of the inphase signal). If you are making an xlr mixer, you are going to either have to:
1) use a differential amp to make the xlr input into one signal, then amplify/mix that, then convert it back into a balanced signal
2) mix the ins and outs separately but proportionately.

First one will likely be easier.

[commathe]

Here is a true-bypass diagram on a 4DPT

[phatt]

Here is a true-bypass diagram on a 4DPT

Hey commathe,
You are making this way complex for no reason.

The circuit does not need to be balanced if using a reasonable quality mixer.
And I'll say it again.
You don't need nor want true bypass when effect is parallel to dry signal.

Search out the *Rane* website for clues and also Also *Jensen* site has lots of pdf stuff which may help you to grasp what it is that you need.
Phil.

[commathe]

Whoops, I misread. I thought he was looking for an XLR true bypass looper. Didn't realize he wanted the effect loop to be a 1/4" jack

[phatt]

Hey commathe, no harm done ,, I got it a bit wrong as well.

I thought you where the original poster,,,, Hard to keep track of who is who sometimes.

Also the term looper is a bit confusing,, maybe lets call it an *Effects Loop* which is built into most mixers.

This means that the Mic signal has already been Amplified and the circuit is now an active powered signal which means,,
*No need to build anything*.

Just plug in the required FX unit into the correct unbalanced sockets and then use the effect send pot on that channel to get desired FX level.

@ *harrisxr650*,
You just need to familiarize yourself with how mixers work.
Some older mixers use different terms so it can be confusing for the novice.
A monitor send return will likely do the same job as an FX send return.

I could babble on here but you will likely find what you need to understand faster with google. I have no doubt that a few basic terms will reap a basic signal path for a mixer circuit.

For those wishing to understand in-depth;
http://www.rane.com/library.html

And a heap more here;
http://www.jensen-transformers.com/apps_sc.html
Phil.