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Question about VDI + 1/4 inch out

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  1. Using the VDI and the 1/4 inch outputs has been discouraged by psarkissian as it could overload the JTV circuitry. 
  2. We can use the VDI connection with Workbench and the 1/4 inch out because there is no power coming over the VDI/USB cable.

 

Could we remove the power pins in the the VDI connector and use the battery for power allowing us to retain all the other VDI functions? Does anyone know if the pins that supply power to the JTV over VDI do anything else?

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I would recommend an alternate approach suggested by Steve KC / Elantric on the VGuitar forums:

 

<quote>

Its conceivably possible that damage / strain on the Variax internal electronics may occur if you connect  a standard mono 1/4" TS Guitar cable while also using the VDI cable connection. There are internal voltage steering diodes to prevent shorting these two  power entry points   - but Line-6 has seen these fail, and the result is a smoked / burnt VARIAX DSP board   

If you want to be safe while using the VDi cable, always use a 1/4" TRS cable with "open" Ring contact to connect to the Variax 1/4" TRS jack.

But know the Downfall of using a stock 1/4" TRS cable is that you typically are connecting to a battery powered floor stomp FX, but the floor FX will not "turn on" unless the TRS "Ring" contact is grounded.

So build a custom 1/4" Guitar cable with an open "Ring" connection on the TRS (Variax) side, and a normal TS plug on the Amp / FX side.  

</quote>

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That sounds pretty cool snhirsh. Thanks for the post and thanks to Steve KC and Elantric for their VGuitar forums.

 

Wouldn't it be nice if psarkissian gave us his safety blessing?

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That sounds pretty cool snhirsh. Thanks for the post and thanks to Steve KC and Elantric for their VGuitar forums.

 

Wouldn't it be nice if psarkissian gave us his safety blessing?

There'll be peace in the middle east first...;)

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If you want to be safe while using the VDi cable, always use a 1/4" TRS cable with "open" Ring contact to connect to the Variax 1/4" TRS jack.

In the variax manual it says to use a standard guitar cable.

What will using a TRS cable (isn't that also used for stereo?) do to make it safe to use together with VDI?

It's probably my poor knowledge of these things, but I don't get it.

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For the purposes of using Workbench/Workbench HD and Monkey (for Flash updates),

using VDI and 1/4" with battery to keep the USB power from sagging, is okay. Check the

Knowledge Base for more on this, there should be a document spelling out how to do

this safely. It's how I connect to Monkey and Workbench.

 

Doing this with audio engaged is not a good idea. This should be used for Monkey and 

Workbench connecting through the USB interface device.

 

And a reminder,... don't use USB Hubs, passive or powered. Strictly the USB interface that

comes with the JTV's.

 

Thank you.

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In the variax manual it says to use a standard guitar cable.

What will using a TRS cable (isn't that also used for stereo?) do to make it safe to use together with VDI?

It's probably my poor knowledge of these things, but I don't get it.

 

You will have to ask Steve Conrad for more details.  Personally I remain skeptical about the potential for damage when both connectors are in use, but life is too short to butt heads over this issue on a public forum. 

 

I wouldn't give use of both connectors on my JVT-69 a second thought, but everyone needs to find their own level of comfort.

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TRS is typically used for guitars with active electronics in it.

Tip = signal, Ring = DC Volt supply, Sleeve = return or ground.

There should be something about that in Knowledge Base as well.

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Using both connectors at the same time for audio output usage can

stress or over-heat over time, the switches that switch between 1/4" and

VDI as well as the amp chips that would be trying to put out to two outputs

simultaneously, rather than one at a time. These are smaller circuits that

can handle only so much current draw.

 

So be aware and be careful. Thank you.

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Using both connectors at the same time for audio output usage can

stress or over-heat over time, the switches that switch between 1/4" and

VDI as well as the amp chips that would be trying to put out to two outputs

simultaneously, rather than one at a time. These are smaller circuits that

can handle only so much current draw.

 

So be aware and be careful. Thank you.

 

If I understand your position, it's not limited to a power source issue, but a current draw issue regardless of power source. There is just no way around dual audio output without some level of risk. 

 

Thanks for chiming in.

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Correct. You might get away with it for a while,

but eventually, the circuit devil gets its due.

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TRS is typically used for guitars with active electronics in it.

Tip = signal, Ring = DC Volt supply, Sleeve = return or ground.

There should be something about that in Knowledge Base as well.

 

We should be using TRS cables? Or only when using the VDI with the 1/4?

 

I have amplugs that I like to use on my Variax that are mono jack.

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Correct. You might get away with it for a while,

but eventually, the circuit devil gets its due.

The guitar signal is so weak that a headphone can't relay the sound from it without at least a headphone amp. Please excuse my series of questions.

 

Why does a 2nd signal of equal low current put such a strain on the electronics? You said it can handle only that much, would the costs be too high if designed to handle both simultaniously?

How many overload cases is Line 6 aware of from returned guitars? Is it common?

And why isn't it prevented somehow if that dangerous to the point of shortcircuits at worst-case sometimes, if a TRS isn't used when simultanious with VDI-power/-audio-signal according to one report? Any possibility for future improvements?

 

 

 

  

We should be using TRS cables?

Against shortcircuit risks according to another's post if combined with VDI-power-and-audio-signal, but it wouldn't help against the "strain and possible eventual guitar-electronics' demise" argument.

I would recommend an alternate approach suggested by Steve KC / Elantric on the VGuitar forums:

 

<quote>

Its conceivably possible that damage / strain on the Variax internal electronics may occur if you connect  a standard mono 1/4" TS Guitar cable while also using the VDI cable connection. There are internal voltage steering diodes to prevent shorting these two  power entry points   - but Line-6 has seen these fail, and the result is a smoked / burnt VARIAX DSP board   

If you want to be safe while using the VDi cable, always use a 1/4" TRS cable with "open" Ring contact to connect to the Variax 1/4" TRS jack.

But know the Downfall of using a stock 1/4" TRS cable is that you typically are connecting to a battery powered floor stomp FX, but the floor FX will not "turn on" unless the TRS "Ring" contact is grounded.

So build a custom 1/4" Guitar cable with an open "Ring" connection on the TRS (Variax) side, and a normal TS plug on the Amp / FX side.  

</quote>

You will have to ask Steve Conrad for more details.  Personally I remain skeptical about the potential for damage when both connectors are in use, but life is too short to butt heads over this issue on a public forum. 

 

I wouldn't give use of both connectors on my JVT-69 a second thought, but everyone needs to find their own level of comfort.

How often do you use both outputs simultaniously?

Anyone else?

Because the argument is about strain by repeated over-heating. I tested in the beginning for a few minutes and it works, but there is no easy way for me to measure the temperature of specific components in the proces. I've a bad experience with passive cooling when overloaded, especially when it happens often and for too long.

 

 

I want to use both outputs for recording a clean signal simultaniously with the FHfx Tone. Since FHfx unlike HD500X doesn't have that feature (a second signal chain).

 

Is it possible for a new FH/fx firmware and Remote app release-combo to allow bypassing of the Tone to for instance to the Right channel out through a setting? Or can the FX block be set first and the FX out be used to record a clean signal? Any downside if the latter is already possible?

 

 

Thank you all in advance.

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When playing using the VDI, use the VDI, VDI cable with XLR casings on both ends.

 

When playing using the 1/4" jack and battery, then use a Tip/Ring/Sleeve (TRS) cable.

 

Using both together to play thru, will stress and heat the amp chips, due to the extra

current draw pull-down.

 

You can get away with doing this with the USB Interface for Updates with Monkey,

or doing stuff with Workbench HD,... because the audio circuit is turned-off.

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When playing using the VDI, use the VDI, VDI cable with XLR casings on both ends.

 

When playing using the 1/4" jack and battery, then use a Tip/Ring/Sleeve (TRS) cable.

 

Using both together to play thru, will stress and heat the amp chips, due to the extra

current draw pull-down.

 

You can get away with doing this with the USB Interface for Updates with Monkey,

or doing stuff with Workbench HD,... because the audio circuit is turned-off.

 

So we should still be using TRS even with just the 1/4?

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I'm sorry but I find it very hard to believe that using the 1/4 inch with the VDI stresses anything.  It is a very low level signal.  99% of the power is going to run the DSP which could care less if there are two outputs.

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I'm sorry but I find it very hard to believe that using the 1/4 inch with the VDI stresses anything.  It is a very low level signal.  99% of the power is going to run the DSP which could care less if there are two outputs.

 

Exactly.  Which is why I'm not going to lose a minute's sleep over it in the unlikely event that I ever do want to use both outputs.

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I'm sorry but I find it very hard to believe that using the 1/4 inch with the VDI stresses anything. It is a very low level signal. 99% of the power is going to run the DSP which could care less if there are two outputs.

My wondering is whether there are more staff members that support the strain notion. Or if it's an unconfirmed fear/precaution theory.

 

 

Any specific link to a Knowledge Base page anyone?

 

Edit: minor grammer.

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I still can't tell if he's saying mono 1/4 cables are bad by itself when using the Variax. It seems a bit anal, and I would of heard about this earlier.

 

A lot of guitarists use mono 1/4 cables for guitars as there's not really any need for a stereo cable with guitars.

 

Like I said, I use amplugs which are mono, is that going to damage my Variax or is the whole notion of using a TRS cable suggested towards using a VDI cable at the same time?

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Exactly. Which is why I'm not going to lose a minute's sleep over it in the unlikely event that I ever do want to use both outputs.

Lol...seriously. Reading this thread, I find myself wondering a whole lot more about why I'd ever want to do this in the first place, rather than pondering whether or not anything would catch fire. Do we need a third output so we can simultaneously spit out notes in Morse code, too? Oooohh...maybe an interface that will sync the stage lights with every note I play. ;)

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I agree that it's not that interesting to do this but it should not hurt the electronics.  If it does, it is a very poor design.  Also there is no reason to use a TRS cable for the 1/4 inch unless you are using the remote power supply that requires it. 

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There is a reason,...

T= signal

R=+Vdc

S= ground return

 

You don't want any two of those to be shorted to one another.

 

Poor design? Not really,... it's poor if you want to do something with

it that it wasn't designed to do in the first place. For what it was designed

to do, it works pretty good, or I wouldn't own four of them myself.

 

For going beyond and outside the parameters it was designed for,...

well that's something else to consider. It's designed to do what it does,

goes outside of that and you'll problem find a glitch.

 

You wouldn't drive a Mini Cooper out into an area that requires a four wheel drive vehicle.

 

 

Man goes to a doctor, puts his arm into a yoga position and says it hurts when I do that.

Doctor says, "well then don't do that".   So, don't go outside of the design parameters.

 

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You wouldn't drive a Mini Cooper out into an area that requires a four wheel drive vehicle.

 

You can, when one condition is satisfied:

 

"All rental cars are off-road vehicles. True, you can't always get them back, but that's not really your problem, now is it?"

-P.J. O'Rourke

 

;)

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When using a mono cable, the +Vdc internal to the Variax should be isolated from ground by a diode so connecting them together should not stress anything.  Only when using an external power supply is the power supplied on that line through the diode.

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There is a reason,...

T= signal

R=+Vdc

S= ground return

 

You don't want any two of those to be shorted to one another.

 

Poor design? Not really,... it's poor if you want to do something with

it that it wasn't designed to do in the first place. For what it was designed

to do, it works pretty good, or I wouldn't own four of them myself.

 

For going beyond and outside the parameters it was designed for,...

well that's something else to consider. It's designed to do what it does,

goes outside of that and you'll problem find a glitch.

 

You wouldn't drive a Mini Cooper out into an area that requires a four wheel drive vehicle.

 

 

Man goes to a doctor, puts his arm into a yoga position and says it hurts when I do that.

Doctor says, "well then don't do that".   So, don't go outside of the design parameters.

 

It is poor design. 

 

So apparently I can't use my Amplug anymore because it's only Tip+Sleeve.

Thanks I really appreciate that.

 

If this is the case then I guess they should of specifically told everyone not to use mono cables, something that A LOT of people are probably going to do because most guitarists just use those cables for their guitars in the first place, so you're telling me that everyone is going around damaging their guitars because Line 6 weren't smart enough to design a circuit that makes sure that it doesn't get shorted out when using a mono cable.

 

Ok so I guess that means there's a crap load of guitarists getting ready for a dead variax soon.

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Also, if we need to use TRS does it really matter? Doesn't the end result connect to a TS jack if it's say, an amp? So you're still connecting ground ring and sleeve, just at the other end of the cable.

 

???????????????????????????????????

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TS and TRS end to end, connected with a TRS cable, Ring remains open. Removing the burden on the Variax protection mechanism, whether diode or something. That seems to be the staff recommenation in this thread. TS cable the Sleeve/return-ground is over the entire supposed Ring space up to the Tip, so RS of Variax are over the same line. It works, but it seems staff says it's not risk-free no matter the technological precautiomnthus far. Whether design limitation or incidental bad component. I also understand the confusion. And I agree that it doesn't have to be rediculous to be robust with existing connections on the Variax t audio equipments, out to in.

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TS and TRS end to end, connected with a TRS cable, Ring remains open. Removing the burden on the Variax protection mechanism, whether diode or something. That seems to be the staff recommenation in this thread. TS cable the Sleeve/return-ground is over the entire supposed Ring space up to the Tip, so RS of Variax are over the same line. It works, but it seems staff says it's not risk-free no matter the technological precautiomnthus far. Whether design limitation or incidental bad component. I also understand the confusion. And I agree that it doesn't have to be rediculous to be robust with existing connections on the Variax t audio equipments, out to in.

 

So we need a connection where ring sleeve is not connected? 

How are we to be sure it's not connected when running it into a TS jack?

 

So I need to buy some kind of adapter.

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So we need a connection where ring sleeve is not connected? 

How are we to be sure it's not connected when running it into a TS jack?

 

So I need to buy some kind of adapter.

 

An adapter to ensure S never get connecteted to R is cheap, but it could suck estatically for instance.

 

Normally a TS "socket" by design doesn't have a Ring connector to make contact with the Ring portion of a jack, so the Ring remains electrically open; no closed circuit; no electrons circulation.

 

https://youtu.be/cVRlkUPgP3U

 

One could use a multimeter with a TRS cable into the Amp one is interested in, and then measure whether there is any resistance (Edit2: through the Ring portion, in contrast to a closed circuit) with the approperiate test current setting on the multimeter?

 

Edit: spelling.

Edited by ZenBalancer

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To clay,... termination at the other end matters too.

It's a fine design if used as intended. 

 

It's been like that since the beginning of Variax. the TRS configuration

adheres to AES standards for signals with a DC voltage on a 1/4" plug/jack

configuration (including those used in active guitar circuitry).

 

Don't try over-think it, make it simple for yourselves, just use a TRS cable.

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This is probably the closest thing I can find to a converter. Obviously I would need to figure out which one is tip and which is ring

http://www.ebay.com/itm/Hosa-1-4-TRS-Male-to-Dual-1-4-TS-Female-Adapter-YPP-117-1-4-Stereo-Breakout-/321929583859?hash=item4af47f9cf3:g:fRcAAOSwAKxWVBtt

 

Black is the Tip according to the label in the picture. But multimeter when used correctly is your friend.

 

Edit: grammer.

Edited by ZenBalancer
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To clay,... termination at the other end matters too.

It's a fine design if used as intended. 

 

Don't try over-think it, make it simple for yourselves, just use a TRS cable.

 

Again, I like to use these:

J15230000000000-00-500x500.jpg

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It is poor design. 

 

So apparently I can't use my Amplug anymore because it's only Tip+Sleeve.

Thanks I really appreciate that.

 

If this is the case then I guess they should of specifically told everyone not to use mono cables, something that A LOT of people are probably going to do because most guitarists just use those cables for their guitars in the first place, so you're telling me that everyone is going around damaging their guitars because Line 6 weren't smart enough to design a circuit that makes sure that it doesn't get shorted out when using a mono cable.

 

Ok so I guess that means there's a crap load of guitarists getting ready for a dead variax soon.

 

Does anyone remember that TS cable being discouraged anywhere else in Line 6 Variax manuals or knowledge base?

 

Because regardless of design limitations or incidental bad protection mechanism component, clay-man has a point.

 

All the Variaxes using a TS cable all around the world are at risk?

 

Time to be paranoid.. and suggest something comedic:

cdda05fd1c938da7ac5fa18549346f01.jpg

 

But the current of the guitar signal going from tthe Tip also back to the Variax Power-Ring, should be too low for a real challenge to the protection mechanism. Although no invisibility is involved. The worry is not completely baseless and is scandelous to the brand imo. No one will notice as long as the protection mechanism doesn't fail. I would imagine much more returned guitars on that basis alone if it wasn't incidental component fail of the protection mechanism.

 

It's much lower risk than simultaniuos audio-signals from the Variax outputs according to the staff most active on the forum.

 

Edit: grammar.

Edited by ZenBalancer
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