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Octo777

Issue: Volume Reduction On Stereo Grouped Device!

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Hey guys,

 

Been a while, hope everyone is well!

 

I've not been around much as I've been busy with life and I've not had any major issues with my M20d I am happy to say....until now!

 

This is not a massive issue as there are easy workaround, but I'd rather get to the bottom of it as I've got lots of work coming up involving my M20d.

 

Basically for my Acoustic duo, I run 5 Channels.

 

Inputs 1 & 2 go to a Stereo Grouped Channel to which my Vocalists Voice Live Touch is plugged into.

 

Inputs 2 & 3 go to a Stereo Grouped Channel to which my HD500 is plugged into.

 

Input 5 is a single channel which my Vocal Mic is plugged into.

 

Today about 20 minutes into rehearsal I noticed that the Left Channel (Input 1) of the Voice Live Touch, was registering a LOT lower than the Right Channel.

 

We stopped, I did the usual physical line checks, everything was OK. I tried reloading the set up, but the issue remained.

 

So I did the trusty old "Turn it Off and Back on again" and low and behold, issue gone, both Left and Right Channels registering roughly the same volume as you would expect.

 

We continue to practice and about 25 minutes, later, the same issue reappeared.

 

I've not done any extensive testing other than that if I load up a different set up with the VLT hooked up to Channel 1 & 2, then the issue disappears in the new setup and if I reload my Duo's saved set up, then again, the issue stays gone.

 

Unfortunately, we had to stop rehearsing so I couldn't monitor things and test any more other than the fact that since it last time it happened, I have left the desk on with everything plugged in for the past couple of hours and the problem has not presented itself.

 

The one thing that might be worth noting is that Trim Tracking is turned ON.......

 

Could this issue be caused by Trim Tracking?  (my vocalist does belt out quite a few notes here and there......)

 

Any info or insight would be greatly appreciated.

 

Many thanks,

 

Dale

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So the first thing to check is to flip the input cables and see if the problem also flips.  If it does then the problem is with the sending unit.  If it doesn't then we'll need to look at the mixer.

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Yeah, I did try swapping the cables with the VLT still hooked up and also tried hooking up my HD500 to the same inputs.....the problem remained like I say, till I rebooted  the desk or loaded a new Setup.

 

Everything is working as it should just now and won't be rehearsing again till Thursday so it's doubtful I'll even be able to recreate the issue till then....

 

That said, I normally leave my HD500 set up in channels 3 & 4 for when I am teaching....I may swap to 1 & 2 for now and see if the issue represents itself that way....

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"Yeah, I did try swapping the cables with the VLT still hooked up and also tried hooking up my HD500 to the same inputs.....the problem remained"

 

I'm not certain this answered my question.  I expect the problem would remain but I would need to know if the low side switched to the other side when the input cables were reversed.

 

 

Trim tracking is setup in stereo on stereo presets.  That is to say that if it is trigger to take action it does it over both channels so that if one side was the problem it would preserve the stereo balance by operating on both channels equally.

 

That said ... you could try switching the trim tracking off and seeing if it made any difference.  But whatever caused the problem may have self-repaired itself and it might not happen again anyway so this would probably only be helpful if the problem was happening frequently.

 

Another place you could look would to create a new setup from scratch.  It is possible that something in the setup you are using is corrupt somehow.

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Sorry, I should have clarified, regardless of a change of input source, the low level remain confined to Channel 1.

 

I left everything as was turned on for an hour or so after rehearsal this afternoon and the problem didn't occur again, but nothing was being processed through the VLT in anger.

 

With the same Set Up loaded, I switched out the VLT for my HD500 and played/taught for a few hours and again the issue never reoccurred.

 

You may well be right in as much that issue may have self repaired.

 

I'll rehearse the same way on Thursday and keep a close eye on things to see if it does happen again.

 

My next logical step would indeed have been to delete the Set Up and create a new one from scratch on the theory that the saved Setup had become corrupt.

 

I shall post back if I discover anything significant.

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Thanks Dale

 

Please keep posting.  If there is a problem we certainly want to know about it.

 

One more thing to try (if the problem re-occurs) would be to move to different inputs.  It's possible there could be a hardware issue and Channel one just drops volume regardless if ti's a stereo or a mono input.  It could simply be channel 1 is at fault.

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OK, so my problems appear to be a tad more severe than first suspected.

 

Basically I believe I have several hardware issues across my inputs.

 

First of all, Channel 1 and I believe now  is now operating at a much lower level than it should.

 

Upon further testing, Channel 6 appears to be operating in a similar manner to Channel 1.

 

Furthermore, through the testing, Channel 10 appears to have developed a more significant fault. 

 

Now, when you turn on the M20d with nothing plugged into any channel inputs, Channel 10 lights Green and a Mic shows on the Stage Background as if it has an XLR plugged into it.

 

If you plug an Mic into Channel 10 it operates as you would expect, until you unplug the XLR from Channel 10 and the channel remains lit Green.

 

Further more, when observing the channel strips, despite nothing being plugged into channel 10, a signal still appears to be getting processed. If you crank the volume, the signal is audible as what I can only describe as "White Noise".

 

If you plug a 1/4" Jack into Channel 10, it operates as it should and when you remove it, the channel shuts off with no Line input or XLR showing green.

 

However, if you plug an XLR back into Channel 10.....nothing happens. It doesn't register as having anything being plugged in.

 

When you power off and on again, regardless of whether you have a cable connected, the XLR Icon is lit up Green and the mic appears on the stage background like before as if you have an XLR plugged in.....

 

So....to sum up, Channels 1 and 6 appear to be operating at much lower volumes in comparison to other channels and Channel 10 has a significant fault where it is not operating automatically as it should.....

 

I'm going to get on the phone to Line 6 in a minute, my only problem is, I have gigs coming up so I can't really afford to be sending my desk away for repairs. :(

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I should add, I have tried a Factory Reset as well as reflashing the Firmware...but still the issues remain which is what leads me to believe it's more than likely a Hardware issue....

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However, if you plug an XLR back into Channel 10.....nothing happens. It doesn't register as having anything being plugged in.

 

 

 

The one is a bit easier.  This usually means the little switch down inside the XLR is stuck.  You can probably free it by pressing on it with a toothpick.  I think the fact that there are so many brands of plugs nowadays and they are not all the same size.  That leaves that little switch without getting the wiggle it expects when you pull out the plug.

 

If you think there is something wrong with the channels you can test using a constant tone and plugging into all channels one at a time.  Start by creating a new setup. That will clear out any old preset info.  Then when you plug in the XLR you'll get the plain mic on the screen.  Just make sure the trim level is the same for all inputs.

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The one is a bit easier.  This usually means the little switch down inside the XLR is stuck.  You can probably free it by pressing on it with a toothpick.  I think the fact that there are so many brands of plugs nowadays and they are not all the same size.  That leaves that little switch without getting the wiggle it expects when you pull out the plug.

 

If you think there is something wrong with the channels you can test using a constant tone and plugging into all channels one at a time.  Start by creating a new setup. That will clear out any old preset info.  Then when you plug in the XLR you'll get the plain mic on the screen.  Just make sure the trim level is the same for all inputs.

 

Spot on with the Channel 10 issue! Used a Toothpick as described and it's sorted.

 

In regards to the other channels, I'm going to look into testing with a constant tone to see exactly what is going on. Using different devices is too inconsistent and leaves too many variables.

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Well maybe the boards can ship with a little plastic toothpick, with a line 6 logo....but it could be called a "mic jack calibrator"?

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So, I've been doing the sound for a local Youth Theatre Production using my L6 gear.

 

So I used the setup I had saved for the production which involved using Channel 1. Everything was good, for a while. Then I noticed the Level dropping on Channel 1 in comparison to Channels 2 and 3 (each had an AKG c1000 plugged in).

 

When I went and soloed Channel 1 to monitor through headphones, it became apparent that despite registering a signal on screen, no sound was actually being produced via Channel 1. This is something that I never tested before as it was usually always a grouped stereo input on 1/2 and I never monitor through headphones for rehearsals or for my acoustic stuff anyway.

 

So basically when I power the desk on, everything works as usual, then after a while, Channel 1 ( and Channel 6 it would seem though not tested thoroughly) starts showing at a lower volume and at that point stops producing any sound...

 

Could this be faulty hardware where the fault is only coming into play after a component has warmed up?

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I took a quick look, but didn't see it. Is this difference on the meters as well? Or just in the headphones? I have issues with the headphones and losing a side, or having it go lower on one side....and I have read that others have had this issue too. And I am sure it is not hardware issue. I have noticed it when listening to all tracks being played at once, or listening to audio tracks being played from my computer through the board. Only in the headphones. The main outs and aux outs are fine.

 

If this isn't your issue, then ignore this. I don't want to sidetrack things. There is another thread on the headphone issue.

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I took a quick look, but didn't see it. Is this difference on the meters as well? Or just in the headphones? I have issues with the headphones and losing a side, or having it go lower on one side....and I have read that others have had this issue too. And I am sure it is not hardware issue. I have noticed it when listening to all tracks being played at once, or listening to audio tracks being played from my computer through the board. Only in the headphones. The main outs and aux outs are fine.

 

If this isn't your issue, then ignore this. I don't want to sidetrack things. There is another thread on the headphone issue.

I can confirm  I am having the same issue with the headphone out. after a while i loose a side. I checked the monitor outs and those didnt loose a side but they are mono. I do not have the main outs hooked up right now so I cant confirm im loosing a side from the main outs

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Hey guys,

 

So I'm done with all my work commitments using my M20d for time being and have been avoiding using Channel 1 as a workaround with no issues.

 

So, I sat down tonight just to confirm a few things and gather some solid evidence before contacting my supplier regarding getting my M20d fixed/replaced under my 3 Year Warranty and I think I've actually narrowed down the problem to a faulty Multi Socket on Channel One (and MIGHT have even fixed it so to speak).

 

Basically, I was able to recreate the issue that I'd been having with my POD Stereo Grouped with Channel 1 and 2 by giving the XLR Jack in Channel 1 a wiggle in the socket and was able to make the signal drop in our out by moving the Jack up or down. (I even videoed the process as evidence).

 

I then did the same test using a single Mic and XLR cable and again was able to make the signal drop and then return to normal.

 

However, since giving the socket a good wiggle with the different XLR cable, I now can't get the signal to drop out any more and for all intents and purposes, have "fixed" the issue....

 

Working on the assumption that the issue I was having was being caused by simply a dirty socket, are there any safe (and more reliable ways other than wiggling the jack in the socket) that I can give the sockets a clean to avoid this issue in the future, that also won't null my 3 year warranty?

 

An air duster perhaps?

 

Once again, any insights to this are greatly appreciated.

 

Many thanks!

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Hi Octo777,

 

instead of using an air duster you could use a vacuum cleaner with this brush end thing attached to it (sorry, don´t know the correct english term for this ;)). If you are using an air duster you might just blow all the crap deeper into the M20d than before. But if you are using the vac cleaner method you have to be carefull to not scratch the surface of the M20d if you are applying too much pressure. And the M20d should not be powered on and not connected to the power chord because vac cleaners could create static load at the tip of the tube. Or maybe a little mini vac used to clean computer keyboards could be the right choice to clean the sockets of your M20d. 

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Unfortunately, the "fix" hasn't really worked and when I turn the M20d on now, the channels on both 1 and 6 are showing the same issues.

 

Granted it is possible to jerk them into life by manipulating the sockets, but obviously, this is not how the M20d is meant to work so I have contacted my supplier to arrange a Warranty repair/replacement.

 

Fingers crossed that whole process doesn't take too long!

 

For those interested, here are a couple of videos demonstrating the issues.

 

First one here shows my Pod HD500 connected to channels 1 and 2 and the intermittent cutting in and out on Channel 1, then how it should be when switching to Channels 7/8 and then back to 1/2.

 



Second video shows the channel cutting in and out via manipulation of the socket.

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So, I just got word from Thomann today that my device is apparently being shipped back to me but that "The indicated defect could not be detected".

I'm obviously not very happy at this point and I've contacted them and asked them to hold the shipping to ensure an engineer has a more detailed thorough look at it and even said I'd provide the above videos for reference, just waiting to hear back.

 

If they send it back with no repair, I'll have to send it back to Line 6 direct and send Thomann the bill.....hah!

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So, I have been working with the issues on channels 1 and 6 (generally avoiding using them) which has been OK for most things since posting this 2 years ago.

However I have some full live work (the first in a while) coming up in the next few months and going on the assumption that it was faulty input sockets, I was looking to have them replaced by Line 6.

However, after having a scan of the forums, I see that many more have reported very much the same issues across different in's and outs and that the fault may have been traced to an unsubstantial Earth on the sockets not making good contact with the chassis of the unit with a tricky looking fix of soldering a wire to each tab and then connecting it a universal earth point on the chassis.

Assuming that this is indeed a reliable solution to the issues reported above, then great!

I am rubbish with a Soldering iron and this is not something I dare attempt myself, despite the fact that my unit is now out of warranty.

I'd be quite happy to pay for work to be done in order to repair my M20d,  but given that I use my desk almost every day for work, I am obviously eager to avoid having to send my desk away......and again this is under the assumption that this will actually solve the issue of the drop outs!

Is anyone aware if this is a solution that a Line 6  service centre would even carry out?

 

Or is there potentially a less technically demanding solution such as simply spreading the tab to ensure it makes contact with the chassis?

I'm really just looking for some clarification before I take steps in either direction.

 

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I have exactly the same problems especially with 1/4 Jack sockets going dead/noisy, and was driven by the headphones cutting out to doing something about it, so having had a bit of practice repairing my Korg N364 with dead backlight and keys and having had a less than satisfactory response from Line 6 Support I dared to open up the M20d....

 

It is quite tight in there and even getting the top off requires gently disconnecting multiple cables between the screen/buttons + sockets on the lid and the main processor on the base.  To get access to the circuit board to do the grounding fix requires disconnecting every socket from the top and I decided that I would only try that if desperate, but I did notice that one of the cables that I had to remove to get in was not properly pushed into place, so I settled for squirting a little contact cleaner onto the connectors as I pushed them back in while closing up the unit again.

 

When I switched it on the problem with the headphones had been resolved, but I haven't fully tested all of the inputs for level and the Bass player is still complaining that his Monitor cuts out. 

 

So you might try cleaning the connectors between the boards - I am going to have to spend time doing a proper test of mine if I can find the hours to do it.

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Good news - for me at least.

 

I have had time this morning to test every physical input (XLR + 1/4 into every Combination and 1/4 into the Lines + Aux), logical input (SD Card + USB) and physical output (4 monitors + mains + headphones) on the M20d and everything is working as I would expect with identical gain levels across all the inputs and across all outputs.

 

[yes including the monitor send for the bass player - maybe his cable was dodgy]

 

So it looks as if a little contact cleaner and resetting the connections between the circuit boards has a good chance of curing these intermittent faults.

 

:)

 

I will obviously keep an eye on everything but at the moment I am somewhat happier than I was a few weeks ago when I thought I had a £1000 door stop.

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That is very interesting Rewolf!

Well after I finished some work with the desk last week, I cracked it open over the weekend to have a look inside and review what I may or not be able to do in regards to the earthing.

I have to say from what I observed, the earthing points on the sockets/pcb looked pretty solid and I saw very little evidence for poor earth contact to be the significant factor in causing these drop outs.....

Through the process of my investigation, I obviously had to disconnect the ribbon cables and then reconnect when putting everything back together.

Now, to be fair, I've not had a chance to check everything extensively yet (I simply focussed on the problematic channels) but I used my desk for a few hours while teaching today and since I had the desk apart, I've had zero drop outs on Channels 1 or 6 that were consistently dropping out all the time before!!!

Like Rewolf, I'll be monitoring things over the next while as well as doing a more specific test in the next few days, but it definitely seems like in some cases, simply reseating the ribbon cables may be all that is required to fix these drop outs......

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I've had very similar problems. Some observations and some work arounds (if your problem was the same as mine).

 

1.  I think it's more common with the corner inputs, 1, 6, 7 and 12.  Can't back that up, just my observation.

 

2.  I think it has nothing to do with trim tracking.

 

3.  When the input level on a channel drops, it can be brought back by taking manual control of the trim on that channel and boosting it.  It seems to jump through some kind of barrier and a small trim increase can result in a sudden jump of input from the channel.  You should then be back to normal operation at least for a while.  

 

4.  When the input level drops, it is frequently accompanied by a low level kind of white noise.   If it sounds like a gentle wind is blowing across an open microphone or maybe like you've blown a speaker, it could be an input drop issue that you need to find.

 

5.  If you have a soundman who's on the ball, he can generally completely nullify this problem by carefully watching the input levels of the troublesome channels, listening for white noise between songs or quiet parts, and "goosing" the trim of channels that are giving you problems.

 

6.  I sent my M20D back to Line 6 twice.  It seems to be working good now but the second time I think they replaced the entire inside of the device.  The first time was right at the end of the warranty and the second time was about six months later.  They did not charge me for either.

 

7.  I think the guys who found that this is a physical grounding issue are right on.  If you can, I would send it back to the manufacturer for service.  My experience with "authorized service providers" is that they have very little idea what they're dealing with.  For something as rare as an M20D, I think you have a low probability of success for problem like this with your local electronics dude talking long distance on the phone with Line6.  Just send it to Line6.

 

8. Monitoring this board I've seemed to notice that service in the US is better than Europe/Canada.  I live in Arizona, less than days drive from the Mothership. They've always been outstanding on the phone and haven't hesitated to take something back for service.  However, it seems like some of the European dudes have ended up with much longer wait times and issues between retailer, manufacturer and service where no one wants to take responsibility.

 

I've been a LONG TIME line6 user and love their products.  I absolutely love my M20D in concept and when it's working correctly.  However It has been the most unreliable piece of gear I've ever bought from them.  I'm praying that they keep in the game with this mixer or some next version that comes along.  They really need to be making a 24/6 version to be serious in the market.  It seems like most of the places I've played in the last year, Presonus has really locked up a lot of that market.

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Mine is still OK.

 

(nooo ... I didn't just tempt fate did I???)

 

I have tracked the Bass Player (+ Singer) "it keeps going quiet on me" problem down to .... the Noise gate on his vox channel!

 

I had been playing at mixing based on a recording and in order to cut as much spill from the drums out as possible I had fine tuned the noise gate to that session. I then forgot about it and in later rehearsals unless he sang as loud the channel was gated down to silence. Doh!  The problem is the noise gate settings are buried down in channel deep tweak so it is not easy to spot.

 

With respect to 4 - when it was having problems - for example on the Line Ins what I saw was Left Input of a Stereo pair got was low level white noise while the Right Input maintained the signal - as if it was not connected to anything. I didn't try tweaking the trim level and we haven't got a sound man, but it would come back by itself after a random period of time.  Re-inserting the Jacks or swapping them didn't make any difference.

 

In the UK since the Yamaha reorganisation we no longer have a Line 6 service centre (we used to have one), we instead have an Authorised Service provider that covers everything for Yamaha and I don't trust them to do decent analysis especially on an intermittent fault and I really don't trust them to give a responsive turn around time by which I mean a week or so.  

 

My suspicion is more like it will disappear at my cost for months and come back as faulty as when it went.  Part of this opinion is based around a "B-Stock Officially Repaired" L2t that I bought from a UK dealer that didn't work with a fault that I found within minutes of opening the box (and most of that was plugging it in).  Now if the UK Official Repair can claim that a speaker is "repaired" when it cuts out as soon as the Fan tries to start how can I trust them with anything like an intermittent fault on something as complex as the M20d?

 

The months duration came from the estimate from the dealer to get that speaker repaired and the at my cost comes from the Line 6 response to my Service Ticket which was a blunt "No Original Receipt... No chance of Line 6 warranty or goodwill contribution" - I was going to be charged for the pleasure of shipping my M20d away for months in order to be charged for an investigation that would conclude there was nothing wrong with it.  

 

Unfortunately for anybody outside of the US "just send it to Line 6" isn't an option.

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Well, just a little update on my previous post.

Since opening up my desk, unplugging and reconnecting the ribbon cables, I have not experienced a single drop out on any channels!

I've been using Channels 1+2 and 5+6 on rotation while teaching/practicing and everything has been perfect.

I am fairly confident at this point that reseating the ribbon cables has been enough to solve this long running issue!

Again, I am obviously going to be monitoring everything extremely closely as I am still hyper paranoid that the issue will return at the most inopportune of moments, but till then, all is good1

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We had a recorded rehearsal on Monday and the Bass Player is now happy with us using and recording through the mixer  :)

 

Even though he did have a drop-out again. :(

 

This time we tracked it down to the XLR to 1/4 Jack lead he uses for his monitor (it is easier to set levels for the 1/4 Line input rather than the XLR Mic input) going intermittent - somehow my load testing of the rig on Sunday without fault while using his monitor and his lead had been lucky in not getting a problem, but replacing that lead with an XLR and reducing the level to the monitor and everything was fine  ^_^

 

Don't you just love trying to solve intermittent audio problems?

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