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Are the Helix 1/4" outs balanced?


zooey
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Would like to reserve the XLRs for FOH, but would also rather run balanced to FRFRs, given Murphy's opinions on random interference.

 

For the record, where are tech specs for the Helix in general? Not in the owner's manual that I found. Went to Sweetwater to get its actual dimensions, for instance?

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The 1/4" outs are unbalanced (mentioned on page 7 of the manual). All of the 1/4" sends and returns are unbalanced as well.

 

As far as tech specs, what are you looking for exactly?

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Thanks Phil, should have looked more carefully. When I didn't find physical dimensions in there, kind of figured that "specs" (whatever that means exactly) weren't there.

 

Far as what else, well nothing ATM, just had been looking recently for dimensions (not in the manual, pretty sure), and the title topic (which I gather was), just wanted to know what places there are to look

 

So I guess running an unbalanced line level signal to FRFRs from Helix isn't a huge deal. Seem the only option, if you want separate control over that vs FOH.

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Thanks Peter, I'd expect that in general. Balanced only matters for hum and other interference rejection, which shouldn't be super important for reasonably short runs at line level. Also, no other choice.

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Hang on. Peter, you're saying you run the 1/4" outs through a DI to the PA? Then I gather you're using the XLRs for your stage rig? Why is that? Is it because you want the DI there to protect against phantom, so you might as well use the 1/4"s for that, leaving the XLRs for stage?

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Hang on. Peter, you're saying you run the 1/4" outs through a DI to the PA? Then I gather you're using the XLRs for your stage rig? Why is that? Is it because you want the DI there to protect against phantom, so you might as well use the 1/4"s for that, leaving the XLRs for stage?

 

I have found devices with XLR outputs to be problematic for decades, except mics, mixers and snakes.

 

I have found that using a 1/4" output through a decent DI (mine is a 40-year old IMP3) is very stable, sounds just as good, and gives me impedance adjustments and ground lift possibilities with just a flick of a switch.

 

Never used the XLR outs in POD HD 500 either. I'd use them in the studio definitely, but there are too many unpredictable things live.

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Thanks Phil, should have looked more carefully. When I didn't find physical dimensions in there, kind of figured that "specs" (whatever that means exactly) weren't there.

 

Far as what else, well nothing ATM, just had been looking recently for dimensions (not in the manual, pretty sure), and the title topic (which I gather was), just wanted to know what places there are to look

 

So I guess running an unbalanced line level signal to FRFRs from Helix isn't a huge deal. Seem the only option, if you want separate control over that vs FOH.

 

Some of the technical information that's not in the manual can be found here: http://line6.com/support/page/kb/_/effects-controllers/helix/

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One thing to note about Helix XLR outputs: you need to make sure that the connecting device (e.g. Mixer) does NOT provide phantom power at its associated inputs.

 

Why is this exactly.  We provide phantom power and it doesn't affect my unit at all that I can tell.

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Funny coming together of two topics in this thread...

 

This page in the official Helix Knowledge Base referred to above talks about why phantom power shouldn't be applied to the Helix XLR outs:

http://line6.com/support/page/kb/_/effects-controllers/helix/helix-xlr-outputs-and-48v-phantom-power-r771

 

FWIW, this thread talks about phantom causing lots of hiss, seems ot be a different issue:

http://line6.com/support/topic/17205-xlr-hiss-phantom-power-and-helix/

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  • 2 years later...

After both measuring and testing, the line outputs on the Helix are impedance balanced IMO. If they were unbalanced the "ring" of the 1/4 inch would read shorted to the sleeve. It does not - it reads ~680 ohms (IIRC). I hooked three connections to my Bose mixer and L1 stick; XLR, 1/4" Left via TRS and 1/4" R via TS. Adjusted all gains on the mixer to the same place (made XLR out Mic level, 1/4" Line level. Results; XLR small hiss - no Hum, TRS same - small hiss no hum, TS small hiss small Hum.

 

Impedance balanced is a method of simply placing a balancing resistor in series with the ring contact to ground. If you feed such an output into a balanced/differential input (most decent mixers line inputs including the BOSE) you get a reasonable amount of Common Mode (hum many times) rejection. It is even better with a true balanced output (either driven (solid state) or transformer based. 

 

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14 minutes ago, Propower said:

After both measuring and testing, the line outputs on the Helix are impedance balanced IMO. If they were unbalanced the "ring" of the 1/4 inch would read shorted to the sleeve. It does not - it reads ~680 ohms (IIRC). I hooked three connections to my Bose mixer and L1 stick; XLR, 1/4" Left via TRS and 1/4" R via TS. Adjusted all gains on the mixer to the same place (made XLR out Mic level, 1/4" Line level. Results; XLR small hiss - no Hum, TRS same - small hiss no hum, TS small hiss small Hum.

 

Impedance balanced is a method of simply placing a balancing resistor in series with the ring contact to ground. If you feed such an output into a balanced/differential input (most decent mixers line inputs including the BOSE) you get a reasonable amount of Common Mode (hum many times) rejection.  I learned of this method as a mixer designer for Mackie in the 90's. It is even better with a true balanced output (either driven (solid state) or transformer based. 

 

Cool. I’m going to test this on mine at home tonight as well.  

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On 6/19/2016 at 1:07 PM, DunedinDragon said:

 

Why is this exactly.  We provide phantom power and it doesn't affect my unit at all that I can tell.

It’s likely that the mixer you connect to have individual phantom power switches. That’s rare in most smaller mixing boards - especially the ubiquitous 8 - 12 channel variety. 

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12 hours ago, Propower said:

After both measuring and testing, the line outputs on the Helix are impedance balanced IMO. If they were unbalanced the "ring" of the 1/4 inch would read shorted to the sleeve. It does not - it reads ~680 ohms (IIRC). I hooked three connections to my Bose mixer and L1 stick; XLR, 1/4" Left via TRS and 1/4" R via TS. Adjusted all gains on the mixer to the same place (made XLR out Mic level, 1/4" Line level. Results; XLR small hiss - no Hum, TRS same - small hiss no hum, TS small hiss small Hum.

 

Impedance balanced is a method of simply placing a balancing resistor in series with the ring contact to ground. If you feed such an output into a balanced/differential input (most decent mixers line inputs including the BOSE) you get a reasonable amount of Common Mode (hum many times) rejection. It is even better with a true balanced output (either driven (solid state) or transformer based. 

 

Couldn't this also be because you are lifting the ground somehow? Can you compare 1/4" -> DI to all that?

 

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Update:

No GND lift anywhere 

All devices plugged into a power strip to a grounded outlet.

Accidentally had phantom to Helix yesterday - you would certainly notice it on mine :-)

- Today I went to repro last nights result and couldn't

- Today

XLR into mixer - Hiss, no buzz

Line out TRS cable into Mixer - Hiss, slight buzz

Line Out --> TS cable into Mixer - Hiss + distinct buzz (louder than I want for an acoustic gig)

Line out to cheap DI (Pyle) - Hiss, no buzz, but not sound great either :-)

Radial JDi will be here Wednesday...

- forgot to try Line out --> TS to DI.... 

 

Sure wish i could just use the XLR outs but my mixer has to have Phantom at times and its global...

 

More info as I get it....

 

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On 6/19/2016 at 3:07 PM, DunedinDragon said:

 

Why is this exactly.  We provide phantom power and it doesn't affect my unit at all that I can tell.

 

Silver is right- others have listed problems with Helix when connected to Phantom power.

Running Phantom/48 volts into the XLR in/outs of Helix is a no-no since they were not / are not designed for that voltage. I wouldn't do it but as always, YMMV all the way to the repair shop. ; )

 

Quote

It’s likely that the mixer you connect to have individual phantom power switches. That’s rare in most smaller mixing boards - especially the ubiquitous 8 - 12 channel variety. 

 

if that's the case I would still use a DI so that the sound guy can make a mistake and it won't matter.

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8 minutes ago, phil_m said:

 

All the 1/4” outs on the Floor, Rack and LT (and HX Effects) are unbalanced. It’s been confirmed by Line 6 many times, and it’s in the manual. The 1/4” o7ts on the Stomp are balanced.

What makes you write that?
There are no specifications in manual. There is only cable use recomendation there for 1/4" outputs.
One and only spec published by Line6 states outputs are impedance balanced.

 

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34 minutes ago, zolko60 said:

What makes you write that?
There are no specifications in manual. There is only cable use recomendation there for 1/4" outputs.
One and only spec published by Line6 states outputs are impedance balanced.

 

 

To be honest, I’ve never seen that linked article, but Line 6 has always referred to them as unbalanced on forums and on the large Facebook group. And impedance balanced output, like that article states, isn’t a truly balanced output, as there’s only one driver. The one thing that’s nice about is you connect it to a typical unbalanced input without having the 3dB signal loss you would normally have connecting TRS balanced to unbalanced.

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To be honest I don't know:
1. Why the author of the manual does not want users to take advantage of CMRR of impedance balanced outputs.
2. Why he/she is calling 20ms RTL drivers "low latency".
3. Why the are no specifications there.
4. Why resolved questions do not come to later manual editions and knowledge base.
BTW: Please vote https://line6.ideascale.com/a/dtd/Specifications-publishingof-I-O-imedances-FS-levels-etc/943915-23508

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It is possible that something electronically is happening when you use a TRS to XLR cable in the output of Helix, but it is not a balanced connection. Line 6 has confirmed that the only balanced inputs or outputs on any Line 6 HX product are the Mic input on Rack/Floor and the 1/4" outputs on Stomp.

 

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2 minutes ago, zolko60 said:

What are you reffering to? What knowlege sources?

I've known this for so long I don't even know where to look, but when it's been asked either on facebook or here, the unbalanced nature of the outputs as noted in the manuals has been confirmed.

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OK. Some of your sources missled you. So what is the reason for insisting this is the case when it is sorted out? You can even pull out your ohmometer and check.
Again - there are no specifications for 1/4" outputs in the manual. You can clearly check it with no eqiupment by reading the manual.

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6 minutes ago, zolko60 said:

OK. Some of your sources missled you. So what is the reason for insisting this is the case when it is sorted out? You can even pull out your ohmometer and check.
Again - there are no specifications for 1/4" outputs in the manual. You can clearly check it with no eqiupment by reading the manual.

Well, it matters not a whit to me, as I use it with a DI anyway and like that solution.

The fact that the TRS to XLR cable changes the signal might not be because it is balanced. Something else could be going on perhaps?

I don't know,  to be honest. Someone from L6 might have to chime in, but it's not really a performance issue is it?

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1 hour ago, PeterHamm said:

Well, it matters not a whit to me, as I use it with a DI anyway and like that solution.

Well, it matters to me and several other people writing in several threads on this forum.

 

1 hour ago, PeterHamm said:

The fact that the TRS to XLR cable changes the signal might not be because it is balanced. Something else could be going on perhaps?

I don't know anything about that "fact".  XLR or TRS is just a type of connector. It does not change anything but interfacing option.

 

1 hour ago, PeterHamm said:

I don't know,  to be honest. Someone from L6 might have to chime in, but it's not really a performance issue is it?

Line6Will stated it officialy in the link I have posted. It could be performance issue when you trust the owner manual and do not take advantage of CMRR impedance balanced out gives you.

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