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Cheaper way to get a Line 6 Variax Cabled Power Kit


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I'd say that, unless there's a significant difference in what you're expecting to read and what you see,  you'll be in good shape.

 

My experience has been that the output of AC supplies, such as the ones for your XPS mini, is generally not that close to the rated value, and is  often a little higher. (not in your case, though...) More significantly, it usually goes into the first stage of an on-board power supply -- almost always into a full-wave or bridge rectifier to convert to pulsating DC, then filtered and regulated by a semiconductor device to create the actual operating DC.  The raw ac voltage from the transformer can also be somewhat dependent on the incoming voltage from your house wiring. Very unlikely to be a problem unless it's way out of whack.

 

Battery voltages are nominal, depending upon type and age. NiMHs are different from Alkalines and nicads. A tenth of a volt is not unusual to see, and it's certainly not a problem. Again, the first thing that an incoming voltage -- ac or dc -- sees is often a voltage conversion or regulation circuit. The actual operating range for consumer equipment is very likely to be + or - a volt or more. They have to account for sagging voltage from batteries before the performance starts to degrade or cut off entirely.

 

Good that it zeroes on your resistance ranges, but even it being off a minor amount there doesn't indicate a significant problem. 

 

I'm betting that it will be just fine to perform your testing!

 

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6 minutes ago, cbrillow said:

I'd say that, unless there's a significant difference in what you're expecting to read and what you see,  you'll be in good shape.

 

My experience has been that the output of AC supplies, such as the ones for your XPS mini, is generally not that close to the rated value, and is  often a little higher. (not in your case, though...) More significantly, it usually goes into the first stage of an on-board power supply -- almost always into a full-wave or bridge rectifier to convert to pulsating DC, then filtered and regulated by a semiconductor device to create the actual operating DC.  The raw ac voltage from the transformer can also be somewhat dependent on the incoming voltage from your house wiring. Very unlikely to be a problem unless it's way out of whack.

 

Battery voltages are nominal, depending upon type and age. NiMHs are different from Alkalines and nicads. A tenth of a volt is not unusual to see, and it's certainly not a problem. Again, the first thing that an incoming voltage -- ac or dc -- sees is often a voltage conversion or regulation circuit. The actual operating range for consumer equipment is very likely to be + or - a volt or more. They have to account for sagging voltage from batteries before the performance starts to degrade or cut off entirely.

 

Good that it zeroes on your resistance ranges, but even it being off a minor amount there doesn't indicate a significant problem. 

 

I'm betting that it will be just fine to perform your testing!

 

Thanks so much again!   I'll press on and see what happens! :-)

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On 9/20/2021 at 4:12 PM, cbrillow said:

If you wish to have a direct link with me, you can do it via Gmail.com, with cbrillow being the first part of the address. I'm always happy to keep in touch and was very pleased to hear that your project worked well!

 

Yeah, that works too, and is easier than using separate parts!

 

My gosh, I guess my first Variax is around 18 years old, or so. I ordered it before they actually started to ship to music stores! The one that I built the power supply for is a 600 that I bought in around 2007 or so. (and probably have played it for less than a couple of hours, total...) 

 

Don't have any idea about the newest line of the Variax, those made since the sale to Yamaha. Maybe they have eliminated use of the XPS?

 

Take care, my friend, and drop me a line via email, if you'd like..

It's good to have a direct contact. As we see, one changing in forum functionality - and contact is lost.

Sure, I will text you via email to show results of my project!

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17 minutes ago, westryder said:

It's good to have a direct contact. As we see, one changing in forum functionality - and contact is lost.

Sure, I will text you via email to show results of my project!

Please do come back here with your results. I'd be very interested.

 

I'll do the same :-)

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On 9/23/2021 at 7:02 PM, mozart999uk said:

Please do come back here with your results. I'd be very interested.

 

I'll do the same :-)

I have already told you about my results a few messages earlier (about xps copy in a box). In that message I meant that I want to show it to cbrillow, because I made it with his help, but the  conversation with him via direct messages was suddenly lost and I had no chance to show what I have built.

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  • 2 weeks later...
On 9/17/2021 at 5:55 PM, westryder said:

 

 

On 9/25/2021 at 10:15 AM, westryder said:

I have already told you about my results a few messages earlier (about xps copy in a box). In that message I meant that I want to show it to cbrillow, because I made it with his help, but the  conversation with him via direct messages was suddenly lost and I had no chance to show what I have built.

Ah ok. Sorry. I misunderstood

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  • 1 month later...
On 9/15/2021 at 9:28 AM, westryder said:

Hello!

 

I have built a power box for Variax 300 using cbillow solution and it works fine. I use it to power a guitar via TRS cable. You can use any voltage boost board. I have not found exactly the same as used cbrillow, so I ordered an LTC1871 step-up board. Its dimensions are exactly 67x44 mm. I have attached a photo. I also have seen a board built on XL6009, I think it will work fine too.

You can just search for "dc-dc step up" and any will be okay if it boosts the voltage. They come in a variety of sizes including models without a screen (it's usually smaller).

 

I use a 2A smartphone charger, it works fine. So 2.1A DC will be okay.

P_20210915_204709.jpg

 

Wow! Thanks SO MUCH for sharing this info!!

I've been trying to find a solution for about six months and am hoping this is it.

I use a Variax JTV69 and a Standard professionally and don't like having to worry about batteries dying on stage.

However, I'm pretty smooth-brained when it comes to electronics. I found the board (on Amazon) that was recommended in an earlier post but I'm not clear on wiring it as well as how to connect it to a TRS cable and a power supply.

If you could provide any advice, I would be SUPER grateful.

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On 11/19/2021 at 2:18 PM, psarkissian said:

Not very useful for JTV, Standard or Shuriken guitars.

More useful for original Variax using alkaline batteries, and that circuitry.

 

The post in which I first proposed using a DC-DC converter to power my Variax 600 discussed an onboard solution that replaced the Variax 6-cell battery holder, and was, indeed, targeted for the original Variax 300/500/600 guitars.

 

But the original circuit can easily be  modified with a few additional components so that it can sit on the floor and provide guitar power via the TRS connector, along with the guitar signal, which is passed through from the Variax to an amplifier. (XLR  connection and functionality are not included.) But it works reliably as a power source, as testified to by Westryder, who wrote 

Quote

I have built a power box for Variax 300 using cbillow solution and it works fine. I use it to power a guitar via TRS cable.

 

Although I defer to psarkissian's official forum voice and expertise,  I would expect that it would also work with other Variax guitars that use the XPS box.

 

Here's a quote from the JTV Pilot's Guide that discusses powering the JTV without a battery:

 

"Note: There are two ways to supply power to Variax without a battery. When connected to VDI Digital Input equipped hardware, such as a POD X3 Live, power is supplied via this connection. Or, use the optional XPSDI direct box/power supply and TRS cable. With this box you can power your Variax and it also works as an A/B box to send your signal out of a DI to go direct to a board or acoustic amplifier with certain models."

 

Variax external power supply (corrected).pdf

Edited by cbrillow
Added quote from JTV Pilot Guide
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22 hours ago, scott4est said:

 

Wow! Thanks SO MUCH for sharing this info!!

I've been trying to find a solution for about six months and am hoping this is it.

I use a Variax JTV69 and a Standard professionally and don't like having to worry about batteries dying on stage.

However, I'm pretty smooth-brained when it comes to electronics. I found the board (on Amazon) that was recommended in an earlier post but I'm not clear on wiring it as well as how to connect it to a TRS cable and a power supply.

If you could provide any advice, I would be SUPER grateful.

Hello!

Cbrillow had alredy posted the wiring diagram above. You can use it to build a power box, it works. BUT I heard once that 2nd generation Variaxes (JTV, Standard...) do not support a power via TRS cable. I don't know is that true or not, but keep that in mind. My thoughts about that: if modern Variaxes support XPS boxes to power guitar via TRS cable, why Line 6 does not sell it anymore? Variax 300/500/600/700 are discontinued and XPS boxes are discontinued. So I think you better to ask official Line 6 support first to figure out if your Variax supports this powering type. But most likely they will say, that modern variaxes do not support this powering method.

 

So if you want to try - it's only at your own risk. Anyway, if modern Variax does not support power via TRS, I don't see a reason for Line 6 to place a TRS socket in the guitar. In that case most likely there is a TS socket in the guitar. You can screw out a socket and figure out a TS or TRS is installed in the guitar. If there is a TS socket (MONO) - I think it's 100% your Variax does not support this powering method. If there is a TRS installed (stereo) - it might support powering via TRS.

 

If you will decide to build a Power box, I will make a photos of my box inside if you like.

 

Have a nice day!

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Yes, cbrillow, I remember it was for the old Variax originally, very good. Yes, it can be adjusted for

JTV/Standard/Shuriken series guitar supply rail. Was hoping you'd chime in to point that out. Very good.

 

Yes, XPS was designed to work with all the Variax guitars. From guitar-to-XPS, use a tip/ring/sleeve plug

guitar cable. From XPS-to-amp, a regular guitar cable will do.

 

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On 11/22/2021 at 11:39 AM, psarkissian said:

Yes, cbrillow, I remember it was for the old Variax originally, very good. Yes, it can be adjusted for

JTV/Standard/Shuriken series guitar supply rail.

It's interesting that you'd make this distinction, which implies that these later models have a different DC voltage requirement than the 300/500/600/700 models of yesteryear. That may in fact be technically true, given that the 1st generation models used 6AA cells for a nominal 9Vdc for their battery supply vs the labeled 7.4Vdc lithium battery used on the JTV. (and, probably, the Shuriken and Standard models as well -- I don't own one of them, so I don't know for sure...) 

 

As we know, battery/cell voltages drift downward as they discharge during use, so there's really a range of acceptable voltages that can be applied without damaging the instrument. I'd not be afraid to apply 10volts to my Variax 500 or 600, feeling fairly confident that the circuit would handle the slight overvoltage. That said, I've adjusted my adapter board to output 9 volts, to simulate a battery. When powered by a battery, there's also a Vmin cutoff voltage, below which the guitar onboard processor will not function. I have a pretty good idea what this range is, in a general sense, but won't throw out numbers that I'm only making an educated guess about.

 

But getting back to your comment about adjusting the modified circuit in a box designed to replace an XPS A-B box, I would guess that the XPS, given that it's designed to work with any of the Variax models, doesn't know or care if it's a 500 or a JTV that is connected to it. So what appears that a safe thing to do would be to adjust the output of the DC buck converter used in these projects to the voltage that is output by an XPS A-B box. (In my opinion, it's probably not really required to take this precaution, but it certainly wouldn't hurt to do it!) 

 

So to take this safe approach, we need to know what voltage an XPS supplies to the guitar. I have two XPS switch boxes, and they're slightly different. The Line 6 logos are different  and the operation of the power LED is also different. One of the boxes came with my original early release Variax 500. The other one was supplied with either the 600 or my JTV 59. I think the documentation refers to the XPS supply as optional, so it most likely came with the 600. I've never even plugged that one in until today, to run a voltage check...

 

What I found is, the output from these two XPS boxes appears to be a well-regulated, nominal 7 volts DC. Specifically, the output of one of them is rock-solid at 6.98 volts, and the other one is 7.01 volts. That's pretty darned close... 

 

So my recommendation to anyone considering using this  adapter scheme to supply power to any model of Variax via the TRS cable, would be to set the output to 7 volts. The guitar shouldn't know any better, and will thank you for it.

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  • 2 weeks later...

Hello there!

For everyone who wants an easy to understand diagram for the Variax power supply via stereo guitar cable, I made it.

 

Here is the list of parts you need to build this box with a links to amazon. Links are just for example so you know how do that parts look. You can order not exactly the same parts (excepting DC-DC step-up board). You can use different TRS/TS jacks, button, USB cable and socket for it.

 

Here is the diagram. I use a box built in according exactly to this diagram with my own Variax 300 and it works fine.

 

Spoiler

980064603_variaxpowerboxdiagram.thumb.jpg.23dbaa83d77292fcb5521989a34dbf39.jpg

 

Here is how my power supply looks inside and outside. There is a small difference between my box and the diagram: two more cables from a button. I used not a simple 2-pin button, but a 4-pin button with a built-in LED indication. But there is no need to use an LED-button, if you will mount your power supply in a box like mine: with a 'window' for a step-up board. There is an LED and a voltage meter on the board, they shine bright when you power-up the board.

Spoiler

660652532_variaxpowersupply1.thumb.jpg.b23a52d5541e69ff3e5e6ed4523fcbe1.jpg

 

544561217_variaxpowersupply2.thumb.jpg.a75a17db8f3b06b46703887e64416f0b.jpg

 

I hope this will help everyone to build your own power supply and become free from batteries!

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And course, remember and reminder,...

Line 6 does not support modifications to it's products.

 

If a product with this or any other mod that affects function was to come across my repair bench,

I would have to I would have to send it back untouched. Failed piezo would be one thing, damaged component

on a processor board plugged into this,... would be sent back. They pay me to only repair Line 6 product here.

 

Since we can't vouch for the abilities of others we don't know out there, his would be at your own risk.

Just so that everyone is aware and reminded.

 

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Having had two XPS units fail (a mini and an A/B) this is great info to have in the future if my current A/B box fades away. I've always avoided having to use batteries in my Acoustic 700 and Standard. And thanks, @psarkissian, for the wise words of caution (and for leaving these posts available to Variax fans).

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Just wanted to give a big "shout-out" to cbrillow for being such a great resource here!

 

I had been searching (off and on) for a Line 6 XPS-AB pedal or replacement alternative for literally months.

I play live extensively with a JTV69 and a Standard and wanted a backup to my original XPS-AB pedal, especially since I didn't really want to have to worry about charging batteries.

Luckily, I found his post. Not only did his solution totally work for me, he was also kind enough to answer some of my incredibly "smooth brained" questions.

If I could build this solution, believe me, ANYONE can do this.

 

Disclaimer - I'm just a guitar player with no technical background in electronics. I'm just sharing my experience. I'm NOT telling anyone to go out there and do this because I don't want to be held responsible if things aren't followed properly :-)

JPEG image.jpeg

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  • 4 months later...
  • 3 months later...

Not an electronics guy here:

 

Is the power requirement different from that of POE (Power Over Ethernet)?

 

It occurred to me that a POE injector with ethernet cable might work purely from a 'power' point of view(?)

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On 8/17/2022 at 4:45 AM, Fnabdog said:

Not an electronics guy here:

 

Is the power requirement different from that of POE (Power Over Ethernet)?

 

It occurred to me that a POE injector with ethernet cable might work purely from a 'power' point of view(?)

PoE is typically 48V. The Variax runs at 9V. Plus the VDI connection is using a custom pin-out, not standard Ethernet. So, no, that wouldn’t work, and could damage the guitar.

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  • 3 weeks later...

This may look like a regular XPS Mini, but inside its really a Frankenstein. My Mini quit working years ago, but I saved the parts. After reading this thread (thanks @cbrillow for the idea and the handy wiring diagram!) I decided to rebuild the old thing. I recycled the case, the power on LED, and the input and output jacks. I used a 2A USB power supply for the voltage in, and dialed in 7V out. The power regulator fits inside the case perfectly, and my Variax guitar is quite happy with the whole shebang.

 

 

xps outside.JPG

xps inside.JPG

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