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Any reason not to ALWAYS use a DI box for FOH?

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Should get my Helix in a day or two, and I'm planning my pedalboard.  After reading through the forum, it seems the consensus is the safest way to interface to FOH is to take the 1/4" -> DI box.  

 

I'm considering buying a stereo DI box, and putting it under my board permanently.  The outputs of the DI box would be run to a panel on the side of the pedalboard for easy access (or just mounted on the edge, whatever).

 

This would avoid the phantom power issue (right?), and allow me to ground lift (which may or may not be effective).   For monitoring I'll be running the Line 6 link to an L2t.  Mono for now, but with the ability to expand to stereo if/when I can.  

 

Is there any reason I shouldn't always use the 1/4" to DI for FOH?

 

 

 

 

 

 

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This is generally a good idea if you're regularly plugging into 'unknown quantity' PAs/desks. Get a good passive DI with a ground lift switch and optional pad to lower the signal should it ever be necessary. The transformers in these boxes will deal with enormous ground differentials far greater than the ground lift on an active output.

 

My favourites are the boxes from Radial. The PRODI2 would do exactly what you want. I have a couple of the StageBug SB-2 units that I use on mono pedal boards.

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Anecdotally, I've used Helix's standard XLR outputs everywhere from massive systems to basements, and have yet to have an issue with level or grounding.

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Cool.  Thanks guys.  Sounds like it falls into the "better to have it and not need it than need it and not have it" category.  

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I exclusively use the 1/4" outs to DI boxes. I have rigorously compared and it sounds the same AND eliminates multiple possible problems.

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Anecdotally, I've used Helix's standard XLR outputs everywhere from massive systems to basements, and have yet to have an issue with level or grounding.

I suppose when the grounding is bad enough to exceed the output common mode of the Helix, there's a good chance it is dangerous too as it's probably a misconnect on another phase. Happened to me (not with the Helix though) at a particular venue that has since been completely rewired for safety. A transformer isolated DI box saved the day, but no one was kissing mics that day I tell you!

 

Level isn't really too much of an issue because you can turn the Helix output way down to compensate for those times when all you have is a blind 'choir' mic receptacle with no way to adjust gain.

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I've done maybe 50 gigs in different venues with the Helix and no DI - almost all of these venues have house systems and have plenty of DI boxes if needed.

Many sound guys use a DI by default - then they don't need to trust your equipment.  But I never do.

As stated above, a dangerous electrical system might be a case where a DI might save you and your Helix, so I'm not going to put using one down - but I'm playing places where that is not an issue.  I don't know how reliable that sort of thing is where you play - its a serious issue with heavy legal consequences in my world.

The Helix has a ground lift - that's the only bit of kit you generally need. You got plenty of level out of the Helix.  I find direct to the PA is working perfectly well............I'd put a DI way down my list - any decent sound guy/system carries a few DIs anyhow.

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This of course all depends on where you play and some styles lend themselves to venues with generally good sound systems and others styles to bad sound systems.

 

A lot of old style churches have a desk in a locked cabinet that may have phantom power permanently enabled. This is not heavy rock, but unless you bring your own PA it's gonna be painful if you don't have a bag of tricks with some problem solvers like a DI, XLR/jack converters, spare leads and a long extension cord.

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Good to know Line6 claims there is no risk of damage to XLR outputs when Phantom is applied, only decrease in output level.

 

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Personally, I have lots of mic cables and would like to use them to connect my Helix to the PA.

 

Is there any reason not to put an XLR-F to TRS adapter (I happen to have several of these) on the mixer end of a mic cable and plug it into a balanced line input? Wouldn't that avoid the phantom power issue? Just set the Helix to send line level?

 

Agreed that a 2-channel DI would accomplish the same goal of not having two long 1/4 to 1/4 cables (plus a spare) just for the Helix.

 

 

Garry

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You can connect how you like even using TS cables, but XLR at mic level/low impedance is the professional standard on stage. Stageboxes usually do not have any other connectivity.

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48 minutes ago, GarrySimmons said:

Personally, I have lots of mic cables and would like to use them to connect my Helix to the PA.

 

Is there any reason not to put an XLR-F to TRS adapter (I happen to have several of these) on the mixer end of a mic cable and plug it into a balanced line input? Wouldn't that avoid the phantom power issue? Just set the Helix to send line level?

 

Agreed that a 2-channel DI would accomplish the same goal of not having two long 1/4 to 1/4 cables (plus a spare) just for the Helix.

 

 

Garry

Helix LT, Floor, Rack and HX Effects all feature no balanced outputs. Every 1/4" audio connection on those is TS.

HX Stomp is the only product in the line that has TRS output, and is the only one that this plan will work properly on.

1/4" guitar cable to DI is a fine and professional way to connect to a PA.

 

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3 minutes ago, PeterHamm said:

Helix LT, Floor, Rack and HX Effects all feature no balanced outputs. Every 1/4" audio connection on those is TS.

Are you sure? The only official spec I found states that 1/4" outputs are impedance-balanced TRS. I know this is not true balanced, but this type of balancing gives fair CMRR and is commonly used nowdays.

 

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31 minutes ago, zolko60 said:

Are you sure? The only official spec I found states that 1/4" outputs are impedance-balanced TRS. I know this is not true balanced, but this type of balancing gives fair CMRR and is commonly used nowdays.

 

The manual for Helix makes no mention of TRS at all. I do not know where that info comes from, but the manual states directly that the outputs are TS unbalanced.

I have no idea about the link you shared.

 

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Huh, I had also thought they were TRS jacks. But in deed, the manual says: "Use unbalanced 1/4" TS cables to connect to your guitar amp, FRFR speaker(s), studio monitors, or other playback system. When using a single amp or speaker, connect only the LEFT/MONO 1/4” jack."

 

'Scuse me while I rewire my studio monitors :p

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7 minutes ago, PeterHamm said:

The manual for Helix makes no mention of TRS at all. I do not know where that info comes from, but the manual states directly that the outputs are TS unbalanced.

Where are the specs in manual? ;)
BTW - Please vote! https://line6.ideascale.com/a/dtd/Specifications-publishingof-I-O-imedances-FS-levels-etc/943915-23508#idea-tab-comments
 

  • Upvote 1

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50 minutes ago, zolko60 said:

 

Page 7, Item 26 on Rev D of manual.

It makes sense they would be TS connections as they operate in the same way as a monitor or Aux line output from a mixing board.  If you use a TRS cable it doesn't really matter as the ring part of the cable is simply ignored.

 

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1 hour ago, DunedinDragon said:

Page 7, Item 26 on Rev D of manual.
 

I am using the latest Hx LT 2.10 Owner's Manual.
On page 7 item 21. "1/4” OUT Use unbalanced 1/4" TS cables to connect to your guitar amp, FRFR speaker(s), studio monitors, or other playback system. When using a single amp or
speaker, connect only the LEFT/MONO 1/4” jack."
This is not specification. This is recommendation for cable usage.
I personally have different opinion of impedance balanced lines usage based on my knowledge and experience. :D
That recommendation does not actually contradicts specification skeleton published online but makes no sense to me. :D

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25 minutes ago, zolko60 said:

I am using the latest Hx LT 2.10 Owner's Manual.
On page 7 item 21. "1/4” OUT Use unbalanced 1/4" TS cables to connect to your guitar amp, FRFR speaker(s), studio monitors, or other playback system. When using a single amp or
speaker, connect only the LEFT/MONO 1/4” jack."
This is not specification. This is recommendation for cable usage.
I personally have different opinion of impedance balanced lines usage based on my knowledge and experience. :D
That recommendation does not actually contradicts specification skeleton published online but makes no sense to me. :D

 

Well the specification is the same as any standard 1/4" line level or instrument level output, thus the recommendation.  The 1/4" and XLR outputs are the typical standards that would be used on any live PA channel input or the same as any PA output to either a powered amp or any powered speakers be they fronts or aux monitors.  You can, of course, change the 1/4" output to instrument level or XLR output to Mic level if you choose via global ins/outs all of which are IEEE and ISO industry defined standards for those types of connections.

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8 minutes ago, DunedinDragon said:

Well the specification is the same as any standard 1/4" line level or instrument level output, thus the recommendation.  

Nope. Specification of 1/4" (or XLR) output describes - type of connector, output impedance and level - in digital devices level can be described as dBu at full scale. Type of balancing is also important - when true balanced differential signal is cold-to-ground shorted you loose 6dB, if impedance balanced you loose only its CMRR. If you can change "level", specification should inform you what is that new level and what is the new impedance. As far as I know there are no IEEE or ISO stricts standards for full scale level and impedance. This is why specification publishing is important for professional use. No guessing, experimentation and measuring is required to get things work together.

 

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I feel confident that if the jacks were balanced, they would have said so. It's not typically something a company doesn't bother to mention. The XLR jacks, for example, say "balanced" even though there's hardly any reason to say that they are since basically every mono XLR connection ever made is balanced. In either case, I absolutely get noise running from the 1/4" outputs, even when using nice Mogami Gold TRS cables, that I do not get when using the XLR outs. So that's a clear enough indication to me.

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