Line 6 demo - guitar hooked up to VDI AND 1/4"

[brue58ski]

I recall that it is an official edict that it is bad to have both the VDI and 1/4" going at the same time.  Well check this Line 6 Youtube demo out. Just something to ponder.

 

 

Perhaps there is no power going to the VDI.

[Charlie_Watt]

I have never seen anything from Line6 officially on this!  I have seen it said in this forum several times but if it was really a design issue, I would have thought they would caution against it in the manual or at least somewhere that everyone who owns a Variax would see it in writing.  IMO it is BS.

[psarkissian]

Not BS,... but it is a strain on the amp circuit in the guitar.

[captainnemo70]

Not BS,... but it is a strain on the amp circuit in the guitar.

 

 

Where has this come from though?, 

 

has there ever been an official comment from Line 6 ?

[psarkissian]

Amp chips in the XT Live headphone output used to blow when someone used headphones

with the wrong impedance range. That problem was solved. Not so easy to do the same here,

it's not entirely the same circuit as the XT Live, but the same kinds of load impedance principles

apply here.

 

I'm the guy that services and repairs guitar here at Line 6, and so I know the circuitry intimately, 

and been using and designing circuits with these chips for decades. So I know what the limits of

the amp chips are. I don't have time or space to do an electronics semiconductor theory class here.

 

If you're going to do something like this, be very careful of how you load it down.

[cruisinon2]

Lmao! Official "oopsies" are one of my favorite things in the world.

 

Secret sauce. Move along, there's nothing to see here...Do as I say, not as I do. 😅

[psarkissian]

No secret sauce, just basic electronics.

 

Paul is in the UK, the vid was made in up'd to You Tube in 2011.

And we haven't had a Line 6 UK, since 2014. So this vid is probably

out of date.

 

Sorry "cruis", no secret sauce stuff here today, just boring facts about audio circuits.

Love these exchanges with you, always a sharp one. Keep up the good work.  :)

[cruisinon2]

No secret sauce, just basic electronics.

 

Paul is in the UK, the vid was made in up'd to You Tube in 2011.

And we haven't had a Line 6 UK, since 2014. So this vid is probably

out of date.

 

Sorry "cruis", no secret sauce stuff here today, just boring facts about audio circuits.

Love these exchanges with you, always a sharp one. Keep up the good work. :)

Roughly translated:

 

"Well that guy was across the pond when he made that video 5 years ago, and we don't have a facility there anymore anyway, so therfore it was OK for him to run both outputs back then." Huh?

 

Who cares how old the video is? Wouldn't make any difference if they had unearthed it in that parking lot where they found King Richard III. It's either OK to run the damn thing that way or it isn't. Or are we to surmise that older JTV's are somehow immune to this circuit overloading problem?

 

If you want plausible deniability, the story actually has to make sense...

[specracer986]

Paul was a presenter at the Line 6 Helix class I went to a month or so ago. He was only using one cable at the time. Perhaps when he made this video he wasn't aware of a potential problem. We all live and learn, don't we?

[psarkissian]

specracer986,... yeah, more than likely. I've had these discussions with my then,

opposite number over there. Might be one of the reasons for the change. Or simply

didn't feel a need for two cables for the Helix demo.

[radatats]

Who cares how old the video is? Wouldn't make any difference if they had unearthed it in that parking lot where they found King Richard III. It's either OK to run the damn thing that way or it isn't. Or are we to surmise that older JTV's are somehow immune to this circuit overloading problem?

 

If you want plausible deniability, the story actually has to make sense...

 

we sometimes wonder why there are no factory reps on the boards and this is why.  The guy tells us its not a good idea, be careful and we give him crap because somebody didn't follow his advice 5 years ago.  He didn't say your JTV will immediately blow up.  WTF?

[cruisinon2]

we sometimes wonder why there are no factory reps on the boards and this is why. The guy tells us its not a good idea, be careful and we give him crap because somebody didn't follow his advice 5 years ago. He didn't say your JTV will immediately blow up. WTF?

OK, you win. The answer made perfect sense. My bad.

[clay-man]

I think it's kind of rude to crap on psarkissian just because it's not an official statement. He just works on the guitars, it's not like he's a high corporate representative that can circulate this information and make a PA about it to Line 6 users. It's probably something he knows out of experience and just wants to help inform us that, Line 6 put something in the guitar that COULD get fried if overloaded.

 

Honestly, maybe Line 6 shouldn't be putting poor components on their products? It's probably bare-bones passable stuff that goes out to try to "save costs" even though these products are nothing to skimp quality with.

 

Let's be honest, we like Line 6 for their innovation, not their quality control.

I still remember when I became Line 6 for a while because my GX had a component that lollipop the bed after 1 year of using the product. 

[eenymason]

If it IS an official Line 6 stance that both outputs NOT be used simultaneously, that information needs to be put out there in an official way, not simply something heard through chinese whispers on this, and/or, other forums. I only stumbled across it by accident on this forum.

I can confirm from experience, that both outputs can be used for an extended period of time, without anything within the cavity of the variax spontaneously combusting/frying/pooping it's pants. I used this method of connecting to a Pod HD500, and Voice Live for approximately a year or so, for, on average 2 gigs per week. I don't question psarkissian's opinion that it shouldn't be done (regardless of the actual chance of damage), but I don't think the current dissemination of information (read, lack thereof) regarding this issue is anywhere near good enough. If anyone has fried the particular component in question, unknowingly, by connecting both outputs simultaneously, then the way I see it, Line 6 is liable, for not making it a part of documentation going out with the guitars.

Maybe in reality, it has happened so infrequently, (with the requisite 666 planets aligning at the appropriate moment), that Line 6 figure it'd cost more to put it out there officially, than repair such a small number of capacitors. Well of course it would, when the unsuspecting customer is paying for said repair!!!

[cruisinon2]

If it IS an official Line 6 stance that both outputs NOT be used simultaneously, that information needs to be put out there in an official way, not simply something heard through chinese whispers on this, and/or, other forums. I only stumbled across it by accident on this forum.

I can confirm from experience, that both outputs can be used for an extended period of time, without anything within the cavity of the variax spontaneously combusting/frying/pooping it's pants. I used this method of connecting to a Pod HD500, and Voice Live for approximately a year or so, for, on average 2 gigs per week. I don't question psarkissian's opinion that it shouldn't be done (regardless of the actual chance of damage), but I don't think the current dissemination of information (read, lack thereof) regarding this issue is anywhere near good enough. If anyone has fried the particular component in question, unknowingly, by connecting both outputs simultaneously, then the way I see it, Line 6 is liable, for not making it a part of documentation going out with the guitars.

Maybe in reality, it has happened so infrequently, (with the requisite 666 planets aligning at the appropriate moment), that Line 6 figure it'd cost more to put it out there officially, than repair such a small number of capacitors. Well of course it would, when the unsuspecting customer is paying for said repair!!!

How dare you inject logic into an emotional conversation?!?!? This is "besmirching vs. righteous indignation" ..."Detached and thoroughly lucid assessment" is down the hall. ;)

[eenymason]

How dare you inject logic into an emotional conversation?!?!? This is "besmirching vs. righteous indignation" ..."Detached and thoroughly lucid assessment" is down the hall. ;)

Actually I was hoping to find the "Line 6 Official/Deadly Earnest Stance Regarding Serious and Unresolved Issues" door, but couldn't see the sign anywhere, and heard some kinda scuffle on the other side of this door, and next thing ya know, I was dragged in by the sudden urge to shout my particular scenario. It's probably not unlike a whole lotta other people's scenarios, but maybe not all ended up with a quietly relieved ending like mine.

I might keep shuffling around the darkened corridors with my trusty head-lamp, and try and search out the "Arguments" door, cos I'm feeling a might angsty as you can tell. :ph34r:

[psarkissian]

Yes Clay,... I'm here to keep everyone's gear from ending up on my bench. Thanks.

As for the components,... they actually pretty good, and I design circuits with these. It's

more about it not being designed for use with both out's simultaneously.

 

If there were more space in side, or a properly impedance matched signal boost attachment

that could do the job without circuit pull-down, then I'd be saying "go for it". But that's not

the case here. Bummer. 

[snhirsch]

Let's assume the 1/4" cable is to be plugged into a guitar amplifier.  Worst case, that will be ~100k ohm input impedance - and probably a lot higher.  You still insist this is an excessive load?  I do not buy that explanation, nor would anyone else with a background in audio circuit design and application.  Line6 can put this issue to bed in a hurry by explaining the science behind these claims. 

[psarkissian]

TRS 1/4" and VDI,.... it's a pair of unequal branches. They won't pull down (load)

the same. So using them both simultaneously creates problems.

 

I can't get any deeper than that about it with end users. And I do have background

in audio circuit design and apps (decades of it). And I've serviced hundreds of these.
I know what they can and can't do.

 

I'm just trying to keep all your gear from ending up on my bench.

[snhirsch]

TRS 1/4" and VDI,.... it's a pair of unequal branches. They won't pull down (load)

the same. So using them both simultaneously creates problems.

 

I can't get any deeper than that about it with end users. And I do have background

in audio circuit design and apps (decades of it).

 

Line6 has to be one of the least forthcoming vendors I've seen in this field in terms of sharing even modest amounts of technical information.  If I"m to take you at your word, then you have a serious design flaw on the JTV electronics.  I cannot even visualize how one could design an audio driver circuit that fragile. 

[cruisinon2]

I cannot even visualize how one could design an audio driver circuit that fragile.

It was cheaper...;)

[clay-man]

It was cheaper... ;)

And my argument is that this is supposed to be a higher end products and there's no excuse for cutting it cheap on important components, which should be ALL OF THE GUTS. 

[psarkissian]

It's not the price of the components, it's that they are low volt components.

Your laptop wouldn't handle an over voltage or high current pull-down, anymore

than a JTV would.

 

Nothing would please me more than to do videos on how stuff works and why.

It would put to rest many misconceptions about many things.

[snhirsch]

Right.  Good thing that the typical load one might have on the end of the 1/4" cable isn't within 2 orders-of-magnitude of presenting a "high current pull-down".   Nothing would please us more than to have Line6 actually be forthcoming with technical details instead of obfuscating what may well be a very logical and simple underlying design issue.  But, the inane level of secrecy goes hand in hand with the decision to withhold the JTV guitar setup specs (string height, trem adjust, etc.) because once upon a time someone, somewhere did something dumb that ended up creating a problem. 

[cruisinon2]

...because once upon a time someone, somewhere did something dumb that ended up creating a problem.

Which would have happened anyway, regardless of what the company does or doesn't disclose. Fools will behave as such no matter what info they do or don't have access to. All the James Bond, "need to know" crap accomplishes is making life more difficult for those of us with an IQ bigger than our shoe size.

 

Secrecy is not a deterrent to anything.

[psarkissian]

No secrecy, no cheap components,....

It simply wasn't designed to be that way, with both outputs running simultaneously.

It's as simple as that.

[cruisinon2]

No secrecy...

Let's have the set-up specs, then...pretty sure the sun will still rise tomorrow even if us mere mortals know what height to seat the pickups.

[psarkissian]

Tried that. Too many so called techs weren't as tech as they claimed. And

so I had to do their set-ups all over again from scratch. So that didn't work.

 

But we're getting off-topic here.

[snhirsch]

Trying to have a technical discussion on the dual-output issue is obviously futile, so I'm done.  But, please, don't insult the user community by claiming "No secrecy".  When it comes to just about any aspect of Line6 instruments beyond playing them and turning the knobs, it all appears to be secrecy.

[cruisinon2]

Tried that. Too many so called techs weren't as tech as they claimed. And

so I had to do their set-ups all over again from scratch. So that didn't work.

 

But we're getting off-topic here.

That was Neanderthal reasoning the first time around, and it still is. Keeping everyone in the dark because of a handful of idiots makes no sense, and it never will, no matter how many times it's repeated. Close all the libraries, and shut down the Internet...knowledge is a dangerous thing.

 

But never mind, I give up too. This is an exercise in futility.