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Battery Drain W/variax Off

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Why does the battery drain so quickly with the 1/4" connected and variax switched off? Ideally there should be no need for power at all when the guitar is switched to magnetic pickups regardless of whether the instrument is plugged in or not. Also the "power-saving" feature that supposedly takes effect when the volume is rolled off doesn't seem to help much. My JTV59 drains completely over night if it is plugged in, is on magnetic pickups and with the volume on 0. Just like it would if I had been playing with variax-models all night. It's ok if I pull the plug, but that should imho not be strictly necessary. It may be that the variax-circuit requires a few seconds to boot so that it would be too slow switching back and forth between piezo and magnetics if the circuit had been completely powered off, but a power-saving circuit should still bring the consumption to near 0 when it is not used.

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It's just the nature of lithium ion batteries. Because the terminals of the battery are connected, there's still leakage from them even if the circuit downstream isn't closed. Even a lithium ion battery sitting by itself loses charge slowly. Pulling the 1/4" definitely helps. You have to think of the Variax like a guitar with active pickups. If you leave that type of guitar plugged in overnight, the battery will die quickly as well.

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..... Ideally there should be no need for power at all when the guitar is switched to magnetic pickups....

I don't think that's true. When switched to magnetic pickups, the Variax OS (it's a computer, after all) still has to be cycling and 'listening' for the command (Model Select knob depression) to instantly turn on its modelling. It's akin to having your laptop computer running and being able to repsond to your keystrokes instantly, even though you may temporarily be reading a book instead. If you want to turn off your computer completely you need to power it off (unplug the guitar cable).

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if there is a way for electricity to flow it will find it. a small light in your car; glove box, trunk. will drain a relatively new battery overnight. is your battery new?

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I don't think that's true. When switched to magnetic pickups, the Variax OS (it's a computer, after all) still has to be cycling and 'listening' for the command (Model Select knob depression) to instantly turn on its modelling. It's akin to having your laptop computer running and being able to repsond to your keystrokes instantly, even though you may temporarily be reading a book instead. If you want to turn off your computer completely you need to power it off (unplug the guitar cable).

Which point I made in the original post. Any computer that requires some form of boot sequence will have to be kept alive to respond within reasonable time in a real-time environment. However, my experience with embedded computer design says that it should be possible to conserve 95% or more of the operating consumption by dropping the clock from GHz to kHz and still be able to wake the device up in less than 1ms when necessary. In this case the switch could generate a direct interrupt to the circuit and it should be able to react fully within a couple cycles. So I wonder why the battery drains nearly as quick when the variax circuit is off as when it is in full operation. It's not unusual for a device that operates for 10 hrs on a battery to stay alive in standby (active but running very slow) for 500hrs or more on the same charge. Measuring current I see about 15-20% reduction with the variax off and volume on 0, which is very far from the reduction seen on many other types of circuits in standby-mode.

 

I'm happy with my JTV. Like with many new guitars it'll take a plek-job before I can get the action as low as I wish, but other than that I have no complaints. It's just that I'm reading about "power-saving features" and can't really find any. 

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It's just the nature of lithium ion batteries. Because the terminals of the battery are connected, there's still leakage from them even if the circuit downstream isn't closed. Even a lithium ion battery sitting by itself loses charge slowly. Pulling the 1/4" definitely helps. You have to think of the Variax like a guitar with active pickups. If you leave that type of guitar plugged in overnight, the battery will die quickly as well.

Any battery drains over time even if it is placed in a vacuum where electrons can't travel, because all known battery constructs have internal leakage. Lithium-ion in general is actually a lot better than many other technologies in this respect. The problem arise with rechargeable cells which shouldn't be discharged below a certain voltage, or they will loose their ability to take charge. To avoid that the equipment, and sometimes the batteries themselves, have a built-in circuit-breaker. A small amount of energy will leak through this circuit, but it is minuscule in most modern battery designs, and certainly insignificant compared to the load of an operational or even "sleeping" variax. 

 

A 1/4" jack used as a power-switch should be a stereo-jack, and wired so that neither the amp nor the magnetic pickups become part of the circuit. I.e. any leakage should happen within the internal circuitry. The variax supposedly has powersaving-features, unlike a plain guitar with active pickups so they don't compare at all. I've got other guitars with active circuitry that uses the jack as power-switch, but there's next to no drain on the battery with the jack plugged if the built-in circuit has powersaving features or other internal power-switching (hardware or software).

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if there is a way for electricity to flow it will find it. a small light in your car; glove box, trunk. will drain a relatively new battery overnight. is your battery new?

The battery is as new as the guitar. It has about 10 charging cycles so far. I have no clue when it was made. I may replace it with an external powersupply feeding through a custom stereo-cable as part of some mods along with new magnetic pickups and coil-tap switches.

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Actually, the battery & electronics go into a low power state (not off) when you roll the volume off on the JTV, and the model knob flashes every few seconds. This is like closing the lid on your pc -- puts it into sleep mode. In that mode, the pc is in a low power state. If you leave it long enough in that state, the pc battery will eventually discharge. To disconnect the battery on the JTV, simply unplug your 1/4" plug from its jack -- it's like active pickups like EMG that get turned on by plugging it in. Even with the volume down, there is drain on those batteries, too... Try it. If your battery still drains, then you might have a battery or internal connection problem with the JTV.

 

My 2 cents.

Dave

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Actually, the battery & electronics go into a low power state (not off) when you roll the volume off on the JTV, and the model knob flashes every few seconds. This is like closing the lid on your pc -- puts it into sleep mode. In that mode, the pc is in a low power state. If you leave it long enough in that state, the pc battery will eventually discharge. To disconnect the battery on the JTV, simply unplug your 1/4" plug from its jack -- it's like active pickups like EMG that get turned on by plugging it in. Even with the volume down, there is drain on those batteries, too... Try it. If your battery still drains, then you might have a battery or internal connection problem with the JTV.

 

My 2 cents.

Dave

I'm not complaining that a sleeping variax is draining the battery, just trying to understand why the difference between active and sleep is so small. I have just completed tests sampling current and voltage over time while the battery discharges one time with the variax active and one time with it in sleep mode (turned off with vol on 0). The sampled data confirm that the energy delivered by the battery during the 2 test-runs is the same. The time from full-charge to voltage-cutoff occur was 11hrs13min with the variax on and 13hrs24min with the variax sleeping. I would expect power-saving to achieve quite a bit more than that. All it needs to do while sleeping is to maintain RAM-contents and state, something that most recent computing devices are able to handle with considerably less than 10% of its operating power-consumption.

 

For reference: I have 2 guitars with active pickups. One has a built-in powerswitch on the volume-pot and thus doesn't pull any measurable current from the battery in 0-position. The other pulls about 2% of its maximum consumption when the volume is on 0.

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change the battery

Wich of the facts presented in this thread make you suggest that this is a battery problem? Both batteries supplied with the guitar work the same, and both charge and discharge the amount of energy mentioned in their specification (calculated from voltage/current/time-plots). I.e the battery delivers the same number of mAh regardless of whether the variax-circuit is active or in sleep-mode, while the discharge-time only varies by a couple hours. 

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Which of the facts presented in this thread make you suggest that this is a battery problem? Both batteries supplied with the guitar work the same, and both charge and discharge the amount of energy mentioned in their specification (calculated from voltage/current/time-plots). I.e the battery delivers the same number of mAh regardless of whether the variax-circuit is active or in sleep-mode, while the discharge-time only varies by a couple hours. 

in which post did you mention 2 batteries? has anyone else had this experience? it may be possible both batteries are defective.  maybe the sleep mode circuit is bad. maybe the charger is defective. obviously, there is current leakage if in fact there is a fault.  you will have to troubleshoot the circuit to find the fault, if any. in which case, you will have to have specifications of the circuit or compare the findings to a known good one. changing the battery will be the easiest and less time consuming. try a different cord. how do you expect anyone to answer your question when you know all the answers but still can't determine the problem. maybe it's supposed to act that way. if so, unplug it. done

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maybe it's supposed to act that way.

I was kinda hoping that someone in or related to the design team may comment on design issues, but this may very well be case. I did some more measurements today and discovered that the digital interface is active even if nothing is connected. It may boil down to the fact that there are opportunities for optimisation in future hardware revisions. 

 

I'm sorry I didn't mention multiple batteries, but a battery seems ok to me when it delivers the prescribed number of mAh in each charge-discharge cycle. Pulling the cord when the guitar isn't used is a good thing to do, but I think that especially those who play mostly magnetic pickups would benefit a lot from an improved sleep-mode.

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Pulling the cord when the guitar isn't used is a good thing to do, but I think that especially those who play mostly magnetic pickups would benefit a lot from an improved sleep-mode.

 

 

I don't understand why pulling the cord isn't a good thing to do. Even if I'm at a gig, I might pull the cable from the guitar between sound check and the show. At home I always just unplug it. It just makes it a non-issue then.

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Yeah I always pack my guitar in its case between practices..  But I Also use the HD500 to power it  though..  But I get your gripe they kinda advertise it as a sleep mode when volume is turned down Or no battery drain.. 

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I don't understand why pulling the cord isn't a good thing to do. Even if I'm at a gig, I might pull the cable from the guitar between sound check and the show. At home I always just unplug it. It just makes it a non-issue then.

I wrote that pulling the plus _is_ wise. This is not a big issue, but I use the magnetic pickups 95% of the time and it's a bit annoying that the battery is draining quickly for no good reason. My solution is to feed power from an external adapter via a stereo cable. I may also use the leftover pickup-ring-switch from my coiltap setup as a circuit-breaker for the battery should i need to use it in the future.

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I wrote that pulling the plus _is_ wise. This is not a big issue, but I use the magnetic pickups 95% of the time and it's a bit annoying that the battery is draining quickly for no good reason. My solution is to feed power from an external adapter via a stereo cable. I may also use the leftover pickup-ring-switch from my coiltap setup as a circuit-breaker for the battery should i need to use it in the future.

seems like i read yesterday that you wrote "pulling the plug isn't a good thing to do". i guess phil and i read it wrong 

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so here are your choices. submit a support ticket, troubleshoot the circuit in the case of a fault, unplug the guitar cord, live with it. i'm sure nobody here can give you the answer  you want.

 

i think there is a fault in the circuit

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Sleep mode is called sleep mode instead of straight up Off for a reason. Like people said, it's a state of minimalising the power consumption, but not being completely off. This is usually so you can go back into operation without waiting for everything to boot up again, and basically go back to where you were right away.

 

Like people said, you need some power for it to sense it being put out of sleep mode. Basically the reason why it can detect when it's on when you plug a cable in is simply because it's completing the actual circuit to power the guitar when you plug in a cable. That's how all power switches basically work. Just cuts off the power circuit or connects it, which is why it has no power drainage because the power isn't connected to the components when it's off.

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Sleep mode is called sleep mode instead of straight up Off for a reason. Like people said, it's a state of minimalising the power consumption, but not being completely off. This is usually so you can go back into operation without waiting for everything to boot up again, and basically go back to where you were right away.

 

Like people said, you need some power for it to sense it being put out of sleep mode. Basically the reason why it can detect when it's on when you plug a cable in is simply because it's completing the actual circuit to power the guitar when you plug in a cable. That's how all power switches basically work. Just cuts off the power circuit or connects it, which is why it has no power drainage because the power isn't connected to the components when it's off.

he wants to know WHY it drains almost as fast on power save mode as power on mode. either that is the way the circuit is designed or there is a fault in the circuit. it could be that both batteries are bad or the charger is bad. if he got a fresh battery it would eliminate the battery, but i think the circuit is bad. i understand he wants to have it plugged in since he uses the magnetic pick ups 95% of the time and just turn the volume down to engage sleep mode and you can't play without draining the battery at a high rate even though your using the magnetic pick ups. it is a waste of energy. 

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I do this, by using a pod... the battery is just like a balance weight in my variax  :D plugged up 100% of the time (weeks into months...)

 

i understand he wants to have it plugged in since he uses the magnetic pick ups 95% of the time...

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I do this, by using a pod... the battery is just like a balance weight in my variax :D plugged up 100% of the time (weeks into months...)

A POD is an expensive power-supply. I won't sacrify my high-end amp-sim-rig for a POD just to power the variax. The problem is solved using an external powersupply and a custom stereo cable. On stage I feed power from a high-capacity-powerpack shared with a wireless transmitter. On top of that I've put Bare Knucle pickups with coiltap using pickup-rings with 2 switches on each ring. 2 switches activate coiltap individually for each pickup. A 3rd switch toggles between split-coils and serial-coils and the 4th switch is connected as a circuitbreaker for the internal battery. That's the best flexibility I can achieve. What remains to be done is a plek-job on the frets, a new (better cut) nut and a set of Gotoh locking tuners which should fit with no modifications.

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A POD is an expensive power-supply. I won't sacrify my high-end amp-sim-rig for a POD just to power the variax. The problem is solved using an external powersupply and a custom stereo cable. On stage I feed power from a high-capacity-powerpack shared with a wireless transmitter. On top of that I've put Bare Knucle pickups with coiltap using pickup-rings with 2 switches on each ring. 2 switches activate coiltap individually for each pickup. A 3rd switch toggles between split-coils and serial-coils and the 4th switch is connected as a circuitbreaker for the internal battery. That's the best flexibility I can achieve. What remains to be done is a plek-job on the frets, a new (better cut) nut and a set of Gotoh locking tuners which should fit with no modification

 

and...?

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and...?

If you read a bit between the lines it should be hard to understand that my point is that the JTV, with some modifications is an excellent instrument. I wouldn't put that much effort into it if it wasn't. The only thing not mentioned above is that I also may make an effort to refinish the neck with a satin surface.

 

In summary, what I would recommend the designers to consider for future designs is:

  • Satin neck finish
  • Locking tuners
  • Stainless steel frets
  • A nut that actually fits the neck
  • A bit more effort on the fretwork. It does need fret levelling (manual or plek) which should be unnecessary for a new guitar in this price-range.
  • More emphasis on the magnetic side w/support for coilsplit
  • Supply a 5m stereo cable (signal+power), a short mono patch (signal to amp), and a box to connect guitar+powersupply+amp for battery-less operation.
  • Re-design the variax-circuit so that it has a decent standby-mode, if the guitar still uses an internal battery. Anything less than 90% reduction of the power-consumption in standby isn't up to modern standards. 90% is acceptable, 96-98% is good.
With an external PS there isn't much need for a battery at all, but that may weaken the argument in favour of buying a POD. The only issue above that I can't address myself is the circuit-design, but I would have been prepared to pay a small premium to have had these things done at the factory. With these relatively minor modifications the guitar is no longer a $700 guitar with expensive electronics, but an instrument that can justify its street price without even considering the advanced insides. It's worth noticing that the US-custom model addresses many of these concerns but I'm certain that the Korean factory could improve things considerably at a fraction of the cost.

 

And your point was?

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if line6 stuff is good enough for steve howe than it's good enough for me

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  • Supply a 5m stereo cable (signal+power), a short mono patch (signal to amp), and a box to connect guitar+powersupply+amp for battery-less operation.

 

they do sell this... 

but i wouldn't want them to include it... as the price is high enough without including it....

 

they currently include the workbench interface... which is worthless to a pod owner....

i'd rather they left that out and dropped the price 100$ (what they charge for it alone)

the battery is also mostly worthless to me... if they left the battery and charger out they could drop another 100$

pod owners don't need it if they use VDI....

 

in any case... i think they would get more owners by finding ways to reduce the price than they will by packaging it up to fit your needs.

 

more owners means more demand to develop and improve the software and technology.... which would probably address some of your other issues.

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they do sell this... 

Unfortunately this product (98-034-0105) doesn't seem to be available from European shops. I was looking for add-ons at the line6 site but didn't know I had to dig that far into their on-line shop to find all the variax parts and goodies. Ah well, I've made my own PS-box which work and use a patch that bypass the amp-sim in my rig so I can do without the 1/4"-XLR switch, but it's nice to know that the alternative exist if someone should ask. Thanks! 

 

I agree on the idea of modularisation to keep the cost of the basic product down, but the QC issues (nut and frets in particular) should be addressed at the factory.

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You could just run your Variax into a Pod HD pro/500 using a Vdi cable and use the unit itself to power the guitar... No battery issues....

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A POD is an expensive power-supply. I won't sacrify my high-end amp-sim-rig for a POD just to power the variax. The problem is solved using an external powersupply and a custom stereo cable. On stage I feed power from a high-capacity-powerpack shared with a wireless transmitter. On top of that I've put Bare Knucle pickups with coiltap using pickup-rings with 2 switches on each ring. 2 switches activate coiltap individually for each pickup. A 3rd switch toggles between split-coils and serial-coils and the 4th switch is connected as a circuitbreaker for the internal battery. That's the best flexibility I can achieve. What remains to be done is a plek-job on the frets, a new (better cut) nut and a set of Gotoh locking tuners which should fit with no modifications.

 

 

You could just run your Variax into a Pod HD pro/500 using a Vdi cable and use the unit itself to power the guitar... No battery issues....

pod is not good enough

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It's just the nature of lithium ion batteries. Because the terminals of the battery are connected, there's still leakage from them even if the circuit downstream isn't closed. Even a lithium ion battery sitting by itself loses charge slowly. 

 

That's not really the nature of Lithium-ion batteries. Most formulations have <5% self-discharge per month, which is very good for a rechargeable (standard NiMh cells can drop as much as 30% in a month). In most cases of what seems like self-discharge, it's a "smart" Li-ion battery losing a little power due to its voltage monitor. And there's nothing magical about batteries being connected -- an open circuit is an open circuit, doesn't matter where that open occurs (and yes, I am an Electrical Engineer... CMU class of '83). 

 

So if there's a noticeable drain, that's an indication that something's still powered. Could be the voltage monitor (my JTV-69 arrives tomorrow), I haven't seen the battery, but if there are more than two terminals, those others are usually for monitoring... this is one of the things that keeps Li-ions, which are kind of a tricky technology, from being overcharged or drained. Overcharging can lead to explosions. Draining below safe limits cause a parasitic effect, pretty quickly killing the battery for good. I used to do lots of work with batteries, in robotics. NiMh were more common than Li-ion... much less energy density, but relatively few problems. Same reason Li-ion only recently made it into hybrid cars.... issues. 

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Most formulations have <5% self-discharge per month, which is very good for a rechargeable (standard NiMh cells can drop as much as 30% in a month).

 

Well, I'm not really in any position to argue about the actual specs of the batteries, but in my experience most lithium ion batteries seem to lose their charge much more quickly than this. It seems to me that when I charged my spare battery in had in the case for two weeks, when I went to use it, it was less than 50% charged. There's no voltage monitor or anything on the Variax battery itself. Perhaps there is some circuit protection built into the batteries themselves.

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I have to agree with the frustration....whatever the cause. Unplugging the cable from the guitar every time I set it down is not very convenient....it's like my acoustic/electric Taylor, if left plugged in the battery drains. With all the technology built into the 89F, I can't believe they haven't figure this out yet. My iPad has a Li-ion battery and its standby time is infinite (not literally, but it can sit weeks)...the volume knob should be the equivalent of the magnetic cover on my iPad...and work the same to save the battery equivalently.

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pod is not good enough

 

Why is the Pod not good enough to power the Variax thru the digital cable? It works fine here.... I run my JTV without ever needing to pull the battery out because of this. 

Of course I never try to run it analog only because I prefer the no noise side of things in the studio...

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I use my VDI connection exclusively -- with no battery in the guitar, Have been for about 8 years now -- beginning with my 300 and the XTL pedal -- then the X3L pedal, up to now with my HD500 and my 59 and 69S. Really no problems - out live or practice. I did bugger one end of my DVI cable (must have stepped on it or something) -- had to use the 1/4" jack, and stick a battery in (I keep one in my guitar case). The batteries hold charge for a very long time.-- I just checked mine yesterday -- months since I checked it last -- and still had all LED's indicating full charge. The first thing I noticed was how much I depend on the HD500 to switch the guitar into different models and the mags with the VDI. Besides power -- that ability is vital to me..... I could not wait to get my replacement cable to be back in business... Now THAT's the technology I want in my setup...

 

My 2 cents.

 

Dave

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Should the variax battery go  completelt flat within a week with the guitar sitting un plugged ?

Regards Dave

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No it should not.  I only charge mine every couple of months.  I don't use the battery - use the VDI and POD HD500X.  I charge it when it gets down to two or 1 led lighted.

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