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XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

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XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Pazu » Tue Jul 16, 2019 11:43 pm

Is it reasonable to use a 3', XLR to 1/4" TRS cable to go from the XLR output of a vocal effect, to the stereo 1/4" input of a delay pedal?

The signals that are output from the vocal effect into the stereo 1/4" input of the delay, won't really be stereo, they are balanced mono, 2 of the same signal, but out of phase with each other (XLR).

I suppose the delay pedal expects an unbalanced stereo signal but, would it matter? Is a 3' cable like this, possibly too long?

Thanks for thoughts!

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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby ef37a » Wed Jul 17, 2019 6:33 am

Won't work, not nearly enough gain in the system IMHO.

One of these https://www.amazon.co.uk/Hosa-MIT-435-X ... C5J26EMQGR

Might help. If the ratio is correct that will give around 20dB of signal boost plus the microphone will get a balanced input which is vital if you are to avoid hums and other noises.

The alternative is a small mixer which should easily have the required gain and will be vastly more flexible, e.g. even quite cheap mixers have an AUX send which you could route to the delay pedal and return to another line input.

I also doubt the pedal has a "stereo 1/4" input" ? The usual setup is a mono jack in and stereo (sort of) out, usually on two jacks.

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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Mike Stranks » Wed Jul 17, 2019 9:04 am

No; what you are proposing won't work and I'd be very surprised if you'll find an off-the-shelf cable that will do what's required.

Just recently out of interest I've been looking at some of these XLR-TRS cables in various configurations and also reading buyer comments about them.

In all cases they're wired for balanced-balanced connection even though they're often advertised for such purposes as 'connect your mic to the input of your camera'. Then you get the angry and disappointed comments from buyers who say 'it doesn't work; it was faulty' etc etc.

The really interesting cases are the splitter cables - eg XLR female to two phonos or TS jacks. I've bought a few out of interest. In ALL cases they're wired incorrectly with pin 2 of the XLR going to the tip of one plug and pin 3 going to the the tip of the other plug. Then people complain about 'funny' sound!

Irrespective of levels, for which Dave is on the case, and assuming that it really is a stereo (and not balanced) input to the pedal then you need a cable with pin 2 of the XLR connected to the tip AND ring of the TRS jack and pin 3 connected to the sleeve.

(I'll leave others to debate whether not it's advisable to bring pin 1 of the XLR into play. These days I don't bother for short interconnects..)
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Hugh Robjohns » Wed Jul 17, 2019 10:02 am

Pazu wrote:Is it reasonable to use a 3', XLR to 1/4" TRS cable to go from the XLR output of a vocal effect, to the stereo 1/4" input of a delay pedal?

No, it's not!

The signals that are output from the vocal effect into the stereo 1/4" input of the delay, won't really be stereo, they are balanced mono, 2 of the same signal, but out of phase with each other (XLR).

Not sure what you mean by 'vocal effect', but if you mean a standard balanced microphone then you are going to have problems with signal level as well as signal format
-- the output from a mic being very much lower than the instrument or line level expected by the delay pedal.

And then you have the unbalanced stereo/balanced mono issue to deal with...

On the upside... the length of cable won't be the problem :-)

Perhaps if you can tell us precisely what you're trying to connect to what we can offer a practical solution.
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Hugh Robjohns » Wed Jul 17, 2019 10:08 am

Mike Stranks wrote:(I'll leave others to debate whether not it's advisable to bring pin 1 of the XLR into play. These days I don't bother for short interconnects..)

Depends on what you're trying to connect to what, and whether the source requires a solid ground.

If you're connecting a balanced dynamic microphone to an unbalanced input, the mic's casework should be grounded to maintain the Faraday shield around the capsule and any internal electronics (transformer, filtering, etc). So the XLR pin 1 should be connected directly to the sleeve of the jack plug.

H
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Mike Stranks » Wed Jul 17, 2019 10:21 am

Hugh Robjohns wrote:
Mike Stranks wrote:(I'll leave others to debate whether not it's advisable to bring pin 1 of the XLR into play. These days I don't bother for short interconnects..)

Depends on what you're trying to connect to what, and whether the source requires a solid ground.

If you're connecting a balanced dynamic microphone to an unbalanced input, the mic's casework should be grounded to maintain the Faraday shield around the capsule and any internal electronics (transformer, filtering, etc). So the XLR pin 1 should be connected directly to the sleeve of the jack plug.

H

Ah! Good point! (It didn't apply in my recent cases, but...)
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby blinddrew » Wed Jul 17, 2019 11:23 am

Pazu, are you running the microphone into a vocal effects unit? And it's the output from that which you want to send to the delay pedal?
If so, what is the vocal effect unit?
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Pazu » Wed Jul 17, 2019 10:58 pm

Many thanks for your thoughts Dave, Mike, Hugh & Blinddrew. KInd of you all to offer up your expertise. I can return the clearly useless cable...

Happy to explain the chain that I am trying to use.

Starting at the microphone end:

AKG C520 MicroMic which is a condenser needing phantom power, has an XLR end.
TC-Helicon Mic Mechanic 2 - it provides phantom power, has XLR in & XLR out.
TC Electronic Flashback Triple Delay X4 - it has 2 ea. 1/4" input jacks, side by side and close together.
Above the pair of jacks in big letters it says:
INPUT
Then below that, in smaller text the left jack is labeled :
MONO
The right hand jack is labeled:
- STEREO
They are both mono 1/4" TS inputs. Wish I had remembered that, clearly the cable I got is useless. The manual clearly indicates that both are mono inputs and the right side signal will represent the right channel for stereo processing/output. If only a left side jack is connected, the pedal processes mono.

I guess what I really need to do, is split off the xlr output of the mic mechanic, spit one output balanced to the board or amp and then another output unbalanced and boosted to the triple delay. i'll have to have a volume pedal after the triple delay so that I can control the level of the effect that is sent and I have one that will work.

Seems like I've got to make a cable to do this, but with the info here, I ought be able to accomplish it.

Thanks again!!!

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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Pazu » Thu Jul 18, 2019 12:49 am

I found this:

https://www.amazon.com/Passive-direct-i ... op?ie=UTF8

I'll try it with short as possible cables.

Thanks!

P
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Bob Bickerton » Thu Jul 18, 2019 1:53 am

I recommend the Radial Vocoloco for this application:

Image

https://www.radialeng.com/product/voco-loco

You can use any (guitar type) stomp box with your microphone.

Bob
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby ef37a » Thu Jul 18, 2019 6:21 am

Can I assume the "board" that one split goes to is a PA mixer and thus a balanced XLR mic input? If so you really need a transformer in the line because if you unbalance the mic pedal feed for the delay the mixer signal will I am sure become noisy.

However, I am not sure the mic pre amp will give enough gain (the TC spec is non-existant) to drive the delay? The latter seems to an "instrument" level device and thus expects signals some 20dB higher than micropnone levels. The Mic mechanic seems designed to drive microphone inputs. How that "auto-gain" system works I have no idea but I suspect is is a fancy name for a form of compressor?

The stereo aspects of both devices are, I think best left alone until you have a clean and functioning mono system? Once there, consider stereo effects if they are desired.

My thoughts return to a small mixer between the Mic Mech' and the delay. That would give you a balanced input and gain plus usually at least two other outputs, one balanced, to feed other devices.
I know it is a lot of bits cobbled together but it is only one addition to the
"mess"!

Lastly for now. Don't want to rain on it but, no mention has been made so far of ground loops? These could test your patience!

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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Hugh Robjohns » Thu Jul 18, 2019 10:22 am

Pazu wrote:I found this:

Not what you need. That is a passive DI box that converts an unbalanced guitar output signal into a balanced mic signal... And trying to use it backwards will mess up the signal levels and gain structure of your signal path.

All you actually need is a cable with a female XLR at one end, and a mono TS plug at the other. ... such as: Image

https://www.ebay.co.uk/itm/3m-Neutrik-Female-XLR-to-Mono-TS-Jack-1-4-Plug-Pro-Lead-Van-Damme-Black-Cable-/261033260918

Better still, make your own or get a guitar shop tech to knock one up for you. XLR pin 1 (cable screen) and pin 3 wired to TS plug sleeve. XLR pin 2 wired to TS plug tip.

If you want to split the signal from the voice processor, then the easiest way is to connect via something like the ART DTI box -- which contains a line isolating transformer. You can take a split from the input side, while the output side will sort out the balanced/unbalanced conversion without messing up the signal levels.

H
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Mike Stranks » Thu Jul 18, 2019 10:30 am

Not quite sure why you're talking of introducing a split feed. May well complicate things.

I can't find any spec-type documentation on the Mic Mechanic so hard to know what signal level is coming out of it. It does say it can be connected to a powered speaker, but there may be an assumption that said speaker has a mic input.

... and we'll cross the bridge of ground-loops if we ever get to it....

A standard XLR female to TS jack will suit you fine. In my experience these are wired correctly! :)
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Sam Spoons » Thu Jul 18, 2019 10:54 am

AFAIK the signal out of the mic mechanic is mic level like most of TC-Helicon vocal boxes (the bigger VL's have line outs or both IIRC).
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Hugh Robjohns » Thu Jul 18, 2019 11:01 am

The manual states the maximum output level is +1dBu... so it's equivalent to a hot mic signal, and should be compatible with a nominal instrument level input for a delay pedal etc.

http://cdn-downloads.tc-helicon.com/media/4475/mic-mechanic-2-reference-manual-english.pdf
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Mike Stranks » Thu Jul 18, 2019 11:42 am

Ah! You found what I couldn't, Hugh!

... and the duplication above was because your post wasn't on the radar when I published mine. I try not to say the same thing as someone else has already said. :)
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Wonks » Thu Jul 18, 2019 11:45 am

Mike Stranks wrote: I try not to say the same thing as someone else has already said. :)

But this is a thread about delay pedals so you

can..


can...


can...
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby ef37a » Thu Jul 18, 2019 12:23 pm

Link won't open and when I paste it into Firefox. "Fille not found"

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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Kwackman » Thu Jul 18, 2019 12:29 pm

ef37a wrote:Link won't open and when I paste it into Firefox. "Fille not found"
Dave.
Working fine on Mac/Safari.
Clicking on it downloads the manual, and copy/pasting the link in a new browser window
does the same.

[EDIT] I copied& pasted in Firefox too (again on a Mac) and works fine.
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Re: XLR to 1/4" - trying to get balanced mic output through an unbalanced delay pedal

Postby Hugh Robjohns » Thu Jul 18, 2019 1:48 pm

Works for me on Win7/Chrome. It doesn't open in a window, though, it downloads the PDF to your appointed downloads folder.

H
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