Troubleshooting digital connection between Helix and Powercab Plus

[lavaspin]

Just took delivery of a Powercab Plus as well as an OEM L6 Link 110 ohm cable. The PC+ works fine if I do 1/4" to 1/4". However, the digital connection is not working. I have my patch set to the AES digital output. According to the manual, it should automatically select the correct global setting. However, when that didn't appear to work, I manually changed the global digital setting from S/PDIF to AES/EB. At that point, I was able to hear an erratic digital popping sound. I made a sound loop on the helix so that I would have constant signal being generated. Occasionally guitar signal would come through just momentarily, at which point I heard it and saw the green signal light on the PC+ light up.

 

I would suspect it's a bad cable. However, I would think L6 checks the cables before sending, so I thought I'd check to see if anyone had other ideas.

 

Thanks!

[LewisBrunton]

Stupid question but are you sure that you are taking the 'AES / EBU L6 Link Out' on the Helix and plugging the cable into the 'L6 Link / AES IN' socket on the PC+?

 

I have done that with mine and did not need to touch the global output settings for it to work.

[cruisinon2]

4 hours ago, lavaspin said:

I would suspect it's a bad cable. However, I would think L6 checks the cables before sending...

 

I wouldn't bet the farm on that one. I seriously doubt any cable manufacturer actually test drives more than a handful from any one production run... otherwise they'd have to pay somebody to sit there all day doing nothing but plugging in one cable after another. 

[lavaspin]

Confirmed. Going to L6 IN on the PC+. At same time that I put up this post, I submitted a warranty request on the cable. I gotta believe that's the issue. But just wanted to check with other Helix users.

[HonestOpinion]

On 8/15/2018 at 3:26 AM, lavaspin said:

Just took delivery of a Powercab Plus as well as an OEM L6 Link 110 ohm cable. The PC+ works fine if I do 1/4" to 1/4". However, the digital connection is not working. I have my patch set to the AES digital output. According to the manual, it should automatically select the correct global setting. However, when that didn't appear to work, I manually changed the global digital setting from S/PDIF to AES/EB. At that point, I was able to hear an erratic digital popping sound. I made a sound loop on the helix so that I would have constant signal being generated. Occasionally guitar signal would come through just momentarily, at which point I heard it and saw the green signal light on the PC+ light up.

 

I would suspect it's a bad cable. However, I would think L6 checks the cables before sending, so I thought I'd check to see if anyone had other ideas.

 

Thanks!

 

You can check if the problem is your new 110 ohm cable by substituting any working XLR cable you have around. The shorter the better. A regular XLR cable may glitch over time on longer runs but shorter ones will generally do just fine for AES/EBU and long or short should be usable for the duration of a L6 Link test. Not to belabor the obvious but make sure your L6 Link cable is plugged into the L6 Link IN connector on the PC+ and of course the L6 Link output on the Helix.

[lavaspin]

Thanks everyone for input. Here's comprehensive info from troubleshooting tests:

• I made sure firmware up to date on both units
• Signal fine using 1/4" cable from: 1/4" Helix  out to Input 1 PC+
• Signal fine use a standard XLR cable from: XLR Helix out to Input 1 PC+
• Signal seems fine using the new L6 Link AES/EBU 110 ohm cable from: XLR Helix out to Input 1 PC+
• Digital clicks and very intermittent signal using same L6 Link cable from: Digital Helix out to Digital in on PC+ (confirmed using IN on PC+)
• --with above digital link, I tried different global settings, i.e., AES and PDIF, and also different sample rates
• --with above digital link, I set my patch to digital out on my patch/preset
• I also tried a standard XLR cable going from digital out to digital in, as someone said that worked for them. It did not work for me. But that may be due to impedence mismatch?

I can't think of any other way to test it. I would still think this is likely a cable issue, and I'll be asking for a new cable. But, if someone else has other ideas, I'm all ears.

[HonestOpinion]

1 hour ago, lavaspin said:

...

• I also tried a standard XLR cable going from digital out to digital in, as someone said that worked for them. It did not work for me. But that may be due to impedence mismatch?

I can't think of any other way to test it. I would still think this is likely a cable issue, and I'll be asking for a new cable. But, if someone else has other ideas, I'm all ears.

 

If you have some other standard XLR cables you can try for the above test of the L6 Link I would give them a try. Unless the Helix or PC+ have an unusually low tolerance for a non AES/EBU cable (110 ohm) you should not have been getting poor performance of the magnitude you describe, particularly with a shorter cable. Assuming you tested with a decent XLR cable this is leading me to believe that barring one of these devices being inherently and unusually persnickety about the cable that there is a problem with the Helix or PC+'s firmware or hardware.  Not recommending it for other than temporary use but I have done multiple runs for L6 Link with standard XLR cable with zero issues. Has anyone else on the forum with a PC+ tested the L6 Link with a standard XLR cable? If so, did it work properly? Definitely worth swapping out your 110 ohm cable for another 110 ohm, just surprising if the connection is that sensitive to the cabling. If so you are probably going to want a backup 110 ohm cable anyway.

[lavaspin]

I was worried about this possibility after the XLR cable didn't work. I'll borrow another XLR cable and give it a try and respond again.

 

Just to confirm the Helix settings for using the DLink:

• Set preset out to Digital
• You shouldn't have to adjust global settings, correct? The way I read the manual, the Helix is supposed to recognize the DLink
• But I have been putting the global setting to AES/EBU, correct?
• Also, I have the sample rate at 48 kHz, although not sure that really makes a difference.

Thanks again.

[HonestOpinion]

15 minutes ago, lavaspin said:

I was worried about this possibility after the XLR cable didn't work. I'll borrow another XLR cable and give it a try and respond again.

 

Just to confirm the Helix settings for using the DLink:

• Set preset out to Digital
• You shouldn't have to adjust global settings, correct? The way I read the manual, the Helix is supposed to recognize the DLink
• But I have been putting the global setting to AES/EBU, correct?
• Also, I have the sample rate at 48 kHz, although not sure that really makes a difference.

Thanks again.

 

You are correct, according to the manual you should not have to set the global digital setting to "AES/EBU", it is supposed to auto-sense the L6 Link.  I suppose it can't hurt to set it explicitly when testing with the standard XLR cable although I would think that the auto sensing and setting function would be looking at the signal in the cable, not the impedance. Btw, just curious, have you tried setting your preset's Output block to "Multi"  instead of "Digital", the "Multi" setting also includes digital output. Shouldn't make a difference and if it does this would indicate a problem but would be one of the tests I would run.

[lavaspin]

So, I just confirmed. Same thing with Multi. One more thing I note is this: The digital popping occurs when Helix L6 Link is connected to IN on PC+ even when the volume is off on both units. If I unplug Helix Digital out, the popping ends. So, I don't know how to test whether the hardware issue is in Helix or the PC+.

 

However, I also put a thread up in the last hour or so on the Powercab subtopic area. Someone who appeared to have the exact same issue had to get a replacement PC+.

 

[HonestOpinion]

20 minutes ago, lavaspin said:

So, I just confirmed. Same thing with Multi. One more thing I note is this: The digital popping occurs when Helix L6 Link is connected to IN on PC+ even when the volume is off on both units. If I unplug Helix Digital out, the popping ends. So, I don't know how to test whether the hardware issue is in Helix or the PC+.

 

However, I also put a thread up in the last hour or so on the Powercab subtopic area. Someone who appeared to have the exact same issue had to get a replacement PC+.

 

 

Unfortunately that might be your answer. Might be worth calling Line6 and discussing it with them, or if you have a guitar shop with a PC+ taking your Helix and cable up and testing it but it sounds like a replacement might be in order. At least based on this poster's similar experience. Good luck!

[lavaspin]

For any others, I just want to provide the resolution. The problem was with the Powercab Plus Digital input, or an internal software glitch in the PC+ unit. It was not the cable. I bought from Sweetwater. After describing the problem and the troubleshooting efforts, Sweetwater sent a warranty replacement. Great service from them.