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Is it a bad idea to use 1/4 out and VDI at the same time?

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I sometimes plug in the 1/4 output to my tuner without disconnecting the VDI, so while I am tuning, both outputs are active.  I read in another thread this could potentially overload the circuit and could damage the board.  Any truth to this? (JTV-59)

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Yes there must be some  truth to it since it has been stated repeatedly by Line 6. Having said that I am not personally aware of any user actually having had problems traced to this. Nonetheless I don't think you want to be the first. :-)

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Correct,... don't do that.

 

Had a few main board and jack plate circuits come back damaged. Traced it

to current/load problem, which resulted from running both at the same time time.

 

 

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Can verify mag pup audio is somewhat out of phase between 1/4" phono and VDI-Helix.  

 

Didn't compare model output waveforms as 'was "snooping" something else.  

 

Little point in doing this with potential DC circuit damage.  

 

I get the use of a tuner but just get a good clamp on....

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Reminder,... be sure that it's a TRS (tip/ring/sleeve)1/4" cable and not TS (tip/sleeve) cable,

when using the 1/4" Phone output.

 

It's an active, not passive circuitry, so must bear in mind the TRS, where tip= signal, ring= DC volts,

and sleeve= return.

 

 

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8 minutes ago, psarkissian said:

Reminder,... be sure that it's a TRS (tip/ring/sleeve)1/4" cable and not TS (tip/sleeve) cable,

when using the 1/4" Phone output.

 

It's an active, not passive circuitry, so must bear in mind the TRS, where tip= signal, ring= DC volts,

and sleeve= return.

 

 

 

Wait, excuse me if I'm dumb ('cause I often am) but what are you referring to in the above?  Are you referring to the simple act of plugging a standard guitar cable into the analog output of the Variax?

 

Are we supposed to make sure it's a TRS cable? Because the handbook simply says "standard" guitar cable here. Is there a risk to the unit?

 

Hopefully I'm off on I90 and didn't realize what you're referring to.

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Risk to the unit? More like efficiency and performance of the guitar.

Over time it can put stress on the circuit with current flow, by draining

battery quicker. Been like that since the old Variax, and standard way

of doing guitars with active circuits since at least the mid 1970's. Something

to aware of with active guitar circuits.

 

 

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4 minutes ago, psarkissian said:

Risk to the unit? More like efficiency and performance of the guitar.

Over time it can put stress on the circuit with current flow, by draining

battery quicker. Been like that since the old Variax, and standard way

of doing guitars with active circuits since at least the mid 1970's. Something

to aware of with active guitar circuits.

 

 

 

Cool. Thanks for the reply and explanation. I've never had an active circuit guitar until the Variax, and had no idea there was an advantage to a TRS cable.

 

It looks like I'll be heading off to my local music store . . .

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There are some good cables out there for that. Know about the active circuit stuff because I and 

the bass player for the band Iron Butterfly used to be among the circuit geeks of the day, who used to build

and do those mods back in the mid to late 1970's. That TRS configuration eventually became the norm.

 

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On 11/7/2018 at 10:06 AM, psarkissian said:

There are some good cables out there for that. Know about the active circuit stuff because I and 

the bass player for the band Iron Butterfly used to be among the circuit geeks of the day, who used to build

and do those mods back in the mid to late 1970's. That TRS configuration eventually became the norm.

 

 

Just a side note. I have a Vetta amp head that I was looking for a Line 6 FBV footcontroller pedal for. I had the small one and a friend of mine was looking for one of those but I was looking for the big one. I told him if he ever came across a full size one to buy it and I would trade him. So he finds a full size one and goes to the guys house to get it. He said the room he was led into had black light posters, a lava lamp, beads in the doorways, etc. and it turned out the guy had just gotten done touring with Iron Butterfly with his Vetta. I still have that footcontroller. I'm pretty sure his name was Charlie Marinkovich.

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Cool. Met Charlie a couple of times. The present IB line-up, I've come to know Dave Meros (Spock's Beard),

drummer Ray Weston and known guitar player Erik Barnett for sometime now. I still hang with drummer Ron Bushy

and his wife, we all go back a long ways.

 

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I did it for 4 years, never had a problem. That said, I was probably just lucky. I don't do anymore since it was brought to my attention.

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When I customize my Standard using Workbench HD, I run an RJ-45 ethernet cable to the USB dongle (to computer), and a TRS 1/4" from Variax to my Variax power A/B unit (for Variax power), then a 1/4" guitar cable from the A/B box to to an amp (for monitoring while customizing). 

 

Isn't that bona fide and kosher? Or will things eventually explode?

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Using both connectors while using Monkey (for updates, the battery engage to give two green LED's)

or Workbench is in a programming state, shouldn't be a problem. It's in the audio operations of playing

that can add stress to the circuit.

 

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TRS?  Aren't most (if not all) devices that the other end of a guitar cable plugs into TS?  Wouldn't the sleeve/ring get shorted there?  Should I not be using my G50 wireless with my JTV59?

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Haven't had a problem with JTV and G50's.

The internals of the G50 transmitter deal with that. It's an internal circuit thing.

 

Just don't go using the G50 simultaneously with the VDI connection. 

 

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I just got a new JTV-89F and see recommendation to use TRS cable. Is that TRS at both ends or TRS into guitar and TS at other end into pedal board? Mind you am using a G70 for gigs, so this is really just for practice at home. Thanks.

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Yes, TRS at both ends is good.

When running JTV off of its battery, tip= signal, ring= battery, sleeve= ground return.

 

It's been the de facto standard since the mid 1970's for active circuit guitars. Custom 

stuff I used to do for myself and Iron Butterfly, when I crewed for them back in the 70's. 

 

 

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I think I might have missed something here - I can understand the possibility of "overloading the circuit" (I haven't ever used both jacks at the same time but have always wondered about that) by using the two jacks at the same time but I shouldn't be using a TR (standard) cable from Variax to amp (or in my case Helix)? I have always used a TR "standard" cable as the user manual instructs. I see the note about connecting the XPS-DI box with a TRS cable to power the Variax in place of the battery but the manual explicitly says use a standard 1/4" cable for the "analog" output jack. Is this TRS instruction an amendment to the user guide?

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I'm a little confused.  As es345tds stated the manual clearly says "put a standard 1/4 inch guitar cable here" in the description of the Analog output.   I primarily use the VDI to my Helix, but I have occasionally used the battery/analog output to play through a traditional amp.

 

Also, I find it interesting that the subject is about using both output at the same time and the consensus is that is bad, however you must use both when connecting to the workbench via a PC.   Granted in that scenario the 1/4 cable doesn't need to plug into anything, but both are used.  

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3 minutes ago, amorris1972 said:

Also, I find it interesting that the subject is about using both output at the same time and the consensus is that is bad, however you must use both when connecting to the workbench via a PC.   Granted in that scenario the 1/4 cable doesn't need to plug into anything, but both are used.

 

amorris - I'm pretty sure I saw a comment about the fact that the 1/4" plug merely powers up the battery for use with the VDI connection so the two connections aren't really being used in the circuit together. Hope I understood what I just passed along to correctly. Maybe some else will jump in on this one since I don't remember where I saw that statement.

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Correct es345tds,... programming is one thing, playing through it is something else.

Just had one on my bench a week or two ago, took out the main board and the battery box circuits because of that.

 

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22 hours ago, psarkissian said:

Correct es345tds,... programming is one thing, playing through it is something else.

Just had one on my bench a week or two ago, took out the main board and the battery box circuits because of that.

 

 

 

Were you modding that guitar or was that a remove/replace thing you did?

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It came in for repair. The board was dead, component going to the VDI and the TRS were damaged or shorted

from too much current pull, and the power management program in the battery box board was wiped. And he did

it with inside the box, which made it worse.

 

In programming or update mode using Monkey or Workbench HD, different circuitry is engaged, current draw is different,

and so it's not a problem.

 

TRS and VDI simultaneously,... don't do that.

 

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Sorry to drag this out but I might as well get more confusion out of the way. I am going to keep a "phono" plug (with no cable attached) handy for powering up the variax for use with the VDI updates. Would it matter in that case whether it was TR or TRS? Also - Is there a simple explanation for the difference in the circuitry used for powering the guitar for audio signal transmission vs simple power associated with VDI updates? I really haven't grasped why the TRS plug works differently from the TR plug for use with the variax application and why Line 6 doesn't speak of it (at least as far as I have seen anyway).

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Use a TRS adapter.

 

Update mode engages different function than when in audio playing mode. And audio playing mode

pulls current/voltage for different functions.

 

In active guitar circuits since at least the mid 1970's, the configuration has been TRS: Tip= Signal, Ring= +V 

and Sleeve= ground/return. It's been something of a de-facto standard since then, and still the case today.

Should be something in the manuals about that, and I constantly post on this here and on the Variax Facebook

group. Sometimes gets lost in all the other posts.

 

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psarkissian

"In active guitar circuits since at least the mid 1970's, the configuration has been TRS: Tip= Signal, Ring= +V and Sleeve= ground/return."

 

Thanks, I understand how the TRS jacks work in normal conditions but with the VARIAX circuit the RING makes the connection that powers up the Variax at it's jack? The unit at the other end (amp, pedal, processor, etc...) with the TS style input doesn't engage the RING on the TRS plug, therefore it never sees the voltage and has no significance - right? I would think that there could be a problem using a TRS plug in a circuit that isn't designed for voltage - something like a stereo pedal that is looking for two guitar signals, not battery voltage - I don't know, just seems like something could go wrong plugging a powered TRS cable into just anything without knowing the compatibility. Please don't say "check with the manufacturer".

 

I have a Yamaha acoustic/electric guitar that can be powered up via a TRS connection with the corresponding Yamaha AG Stomp preamp. This case is another unusual use for the TRS plug - you have to remember to swap out the battery for a "dummy" battery before making this connection. There does seem to be a lot of room for confusion when using the TRS cables and jacks due to their flexibility I suppose.

 

 

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You could check with the manufacturer. But the way jacks are wired and "normaled",

it matters at the guitar end to power the electronics. TRS acts as a switch as well.

Much like the input jack on our DL4 Delay Modeler product.

 

I plug TRS from JTV to other devices (some of them dating back to the 1970's) without

a problem, it's the way the jacks are normal. Certain standards that have been around since

since the days of Alexander Graham Bell that are still used today, with a few today tweaks.

 

Also check the manuals in the Support link here for info on connecting with the onboard battery

or the XPS power wedge. Some good diagrams on how that works.

 

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I don't know what's in the pipeline, they don't tell any that sort of thing.

They just give me stuff if it breaks, and I fix it.

 

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1 hour ago, psarkissian said:

I don't know what's in the pipeline, they don't tell any that sort of thing.

They just give me stuff if it breaks, and I fix it.

 

 

I feel your pain - I've also been a mushroom from time to time. TW :)

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