RE: How to Invert the Piezos on a Variax 500 ?

[Rock_v500]

Hi Everyone,

 

I would like to be able to string my Variax 500 with the heavier strings at the bottom

( using an Ernie Ball Skinny Top Heavy Bottom set -w- gauges 10 to 52 )

 

I understand that i would need to replace the nut with one suitable for this purpose

which i don't think would be difficult, but as I understand it, i would also need to

reposition the piezos in inverted order as well.

 

I have no experience with working on piezos and am wondering how difficult

this process would be ?

 

Any advice and/or information anyone could provide

on this modification would be most appreciated !

 

Thanks,

 

Rick

[psarkissian]

"... but as I understand it, I would also need to reposition the piezos in inverted order as well. " --- Invert?

Are you trying to go left handed with it?

 

Messing with the piezo re-wiring on a 500 bridge is extremely touchy, I've done it. One slip and it's over,

as there are no more 500 replacement bridges.

 

There are 500 left hand guitars out there on sites like eBay and Reverb from time to time.

 

[Rock_v500]

Thank you for your reply to my question, psarkissian !

 

I am not actually trying for a "lefty" conversion, but rather a right handed guitar

with the strings inverted, such as were used by Albert King & Otis Rush, but I'd

want to play it right handed and keep the controls at the bottom of the guitar.

 

I understand your statement about the fact that working with the bridge

on a 500 is a delicate operation, but if i understand the situation correctly

i would not need to mess with the bridge mechanically, and could make the

needed changes by de-soldering the leads from the piezos and after

extending them, re-solder them in the reverse order.

 

I found a video on the internet archives that shows the method for

disconnecting & removing the circuit board and the bridge assembly

which looks pretty straightforward.

 

The only part of the replacement i am unsure of is whether having

soldered on extensions on most of the wires would cause issues

with interference or signal loss, and was wondering if it would be

possible to buy replacement piezos with longer leads in order to

avoid this potential problem ?

 

I would certainly defer to your experience and appreciate any

further insights you might care to offer on this question.

 

Thanks Again,

 

Rick

 

 

 

 

[psarkissian]

"... could make the needed changes by de-soldering the leads from the piezos

and after extending them, re-solder them in the reverse order." --- There is a reason piezo leads

are short, and it has to do with impedance.

 

"... whether having soldered on extensions on most of the wires would cause issues

with interference or signal loss, " --- Yes, the impedance aspects of longer leads. Have to use

the same gauge wire as the piezo leads. One of the reasons it's so touchy a process.

 

Purchasing piezos,... yes, through Full Compass. With longer leads,... no, it's that impedance thing,

that's why they are short to begin with.

 

As always,... modifications to Line 6 products that alter functions, is considered an unsupported modification.

So if errors are made, and the product was sent to me for repair, there is a good chance I would have to send it back untouched.

 

1) One may like someone else's sound, but in the end, it's about finding your own sound.

 

2) You may be able to achieve the goal making use of the Variax Workbench application in the Line 6 site Downloads page.

You would need a computer running earlier OS for that. And would not require physical alterations to the instrument.

 

[Rock_v500]

Hello Again Psarkissian,

 

Thank you for taking the time to respond further to my post

and for your additional explanation of the situation.

 

I now understand your insights regarding the likely

negative impact of trying to modify the wiring of

the piezos to the flex circuit board more fully.

 

I appreciate your suggestion for modding the

tones of the strings with Workbench, but the

reason that i want to attempt the mod in the

first place is to change the way the guitar

would be played physically, especially in

regard to bending the strings by pulling

them down rather than pushing them up

as is normally the case, which would require

the "inverted String" arrangement.

 

If you wouldn't mind one final additional question

i was thinking that one possible way to achieve

my desired result in a less invasive manner might

be to flip the ribbon cable that connects the flex

board to the "hard Board" in the guitar's cavity ?

 

The potential issue with this may be if the two

wider traces on the cable are distinct circuits

rather than a common ( Ground ? ) connection.

 

In that case i was wondering if i could create

a "crossover cable" out of another piece of

ribbon cable which would reverse the piezo

traces but leave the two wider traces in their

original orientation, and use ribbon cable

connectors to attach it on the end of the

existing cable ?

 

This well may be a ridiculous idea,

but i was considering that if it would work

it would be a very non-destructive and

reversible modification ?

 

Thanks Again for taking the time

and effort required to respond to

my questions Psarkissian

 

I very much appreciate your assistance

and expertise in this area !

 

Rick

[psarkissian]

"... to flip the ribbon cable that connects the flex board to the "hard Board" in the guitar's cavity ? " --- not a good idea with a flex PCBA

as it puts stress on the traces within over time.

 

"... potential issue with this may be if the two wider traces on the cable are distinct circuits rather than a common ( Ground ? ) connection." --- Yes,

ground and +volts. Have to have correct polarity or nothing works,... worse, it could fail. "cross over cable",... more solder points and impedance issues.

Need to keep it straight forward.