Can I use a normal guitar on Cabled Power Kit?

[neophitus]

Thats may sound as an stupid question, but can I plug my Gibson Les Paul in the same cable I plug my variax (That one that come out the Variax Cabled Power Kit)? Will the power that powers the variax damage my Gibson?

[blekenbleu]

Using a TRS cable for connecting a Les Paul or any other guitar with passive pickups directly to an amp (or Pod or Helix)

simply leaves the ring (R) connection unused.

A Les Paul should not be damaged, since its jack only connects to tip and shield,

but a powered XPS could be damaged if a Les Paul or other guitar jack shorts ring to shield (some do).

Of course, the XPS could be removed or should at very least NOT powered when a non-Variax guitar is connected.

Power to the XPS should ALWAYS be off when making or breaking connections to a Variax.

 

[neophitus]

I keep my Cabled Power Kit at studio, and powering on and off when changing guitars is a pain in the lollipop... Thats why i´m asking about it...

[blekenbleu]

On 5/7/2019 at 9:33 AM, hurghanico said:

Could you elaborate more on what you said above here?

 

When an XPS is powered, it supplies power on its TRS ring connection, relative to shield.

Then, for a TRS cable already plugged into a Variax:

* if/when the other end of that TRS cable gets plugged into the XPS,

   that plug tip first encounters XPS shield, then ring, sending power to the Variax audio out,

   returning thru the ring connection, which at that instant could be connected to XPS ground.

* If/when a cable already plugged to a Les Paul or other guitar with passive pickups gets plugged to a powered XPS,

   the plug tip sends XPS power to the volume control when it encounters the XPS ring contact.

   - if that guitar volume control is full counter-clockwise, XPS power may get shorted.

   - if that volume control is full clockwise, XPS power may go to pickups. 

 

Else, for a TRS cable already plugged into a powered XPS

 * if/when the other end of that TRS cable gets plugged into a Variax,

    - its plug tip first encounters Variax shield,

       then an instant when tip and ring both contact Variax shield 

       sending XPS power back thru cable tip to DI circuitry in the XPS.

       I don't know whether some impulse also feeds through to amplifier/Pod connect to XPS.

    - next, when that TRS plug tip initially contacts the ring in my Variax 300 connector,

      it measures continuity to shield, effectively shorting the XPS power supply.

    

Diagrams might show this more clearly, but I do not know how to embed them here.

   

[blekenbleu]

4 hours ago, hurghanico said:

 

You need an account to a free host for pictures website like Imgur.com (the one I use), upload your pics over there, and then use your images url links to post your pics here.

In this forum there is a button "insert other media" for this purpose at the bottom right of the window where you write your posts.

OK, that explains a lot of older Line 6 Community Support entries compromised by missing diagrams and images..

 

Meanwhile, diagrams of TRS phone plugs engaging jacks seem to be too risque for the non-dark Internet,

much less with to-scale cross-section diagrams.. but here:

Sadly, the sleeve in simplified diagram to right of the pictured jack is not to scale,

since an actual jack sleeve's depth is over half the nominal 26 mm from jack entrance to tip contact point,

while plug tip-to-sleeve distance is about 12 mm, pretty much guaranteeing:

* plug tip-to-ring shorts whenever TRS plugs pass thru jack sleeves

* plug ring  in contact with jack sleeve when plug tip engages jack ring contact.

 

The TRS jack pictured here lacks those jack ring (and tip?) switch[es] actuated by plug deflections

which happen e.g. in Variax..  Combinations of undesirable (e.g. reverse-polarity power) interactions

as those switch contacts activate (and bounce) during powered plug insertions and retractions

lead me to suppose that worse can happen than I previously wrote,

when plugging TRS with powered XPS.

[blekenbleu]

13 hours ago, hurghanico said:

It seems to me a bit strange that the L6 designers of the Variax and XPS have not considered also this possibility and have not designed the circuits so that they are protected from the possibility of a short when inserting the TRS jack with the power already connected..

 

At least the way to avoid this problem should have been documented in the instructions for use.

I agree and hope that XPS includes >>some<< short-circuit protection,

but had also (wrongly) originally supposed that simultaneous phone jack and VDI connections would be OK...

 

Being naturally pessimistic, I speculate that some damage attributed to simultaneous VDI + phone cable connections

may have been provoked by unfortunate XPS power sequencing, with or without batteries.

 

Note this sequence of connections published in the Variax 600 manual:

"Powering your Variax with the XPS Footswitch is easy.

 Use the included TRS cable (meaning “tipring-sleeve” or also simply known as a “stereo” cable) to connect the Variax to the INPUT jack of the XPS Footswitch.

 Connect the PX-2 power supply to the XPS Footswitch POWER jack,

 and use a standard mono guitar cable to connect the XPS Footswitch’s 1/4" OUTPUT to your amp or effects."