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Graphtech Ghost piezo bleed in alternate tuning remedy (almost)

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I thought I'd start a new topic on this as it could be missed in my reply to another thread...

 

Copy/paste from Graphtech's response to my query regarding the piezo bleed problem in alt tunings:

 

Thank you for the email and support of Graph Tech. I would be happy to comment on your predicament.
 
I have heard some industry feedback that the Line6 platform is somewhat susceptible to some moderate cross-talk (especially when it comes to alternate tunings). Although you can add a mechanical divider of some kind, the best option is to create space between saddles to reduce "bleed". You can remove small amounts of material off the side to improve coupling
 
I hope that helps
 

I responded asking the best way to attack it without damaging the piezos - I await with bated breath, before sallying forth with the bastard file... :ph34r:

 

Can't wait to get rid of the cross-talk problem in alternate tunings - it was there before changing to the Ghosts, but I think they make it worse than the L R Baggs piezos - the only way in which the original piezos were better than the Ghosts IMO.

 

As soon as I get the reply to the latest query to Graphtech, I'll put it up here.

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Make sure you have turned down the string volume on all strings to compensate for the much higher output of the Ghost Piezos.  I tried my Variax 500 first without doing this and it was way overdriven and it did not sound right at all.  I went to about 50% to get a reasonable output that is probably about where the old piezos were.

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Can't wait to get rid of the cross-talk problem in alternate tunings - it was there before changing to the Ghosts, but I think they make it worse than the L R Baggs piezos - the only way in which the original piezos were better than the Ghosts IMO.

 

 

I can confirm the Ghosts exhbit high crosstalk, and RMC Piezo Pickups have the lowest crosstalk 

 

I once put Ghost Piezos on my Variax 600,  - (to get the tremolo to work during dive bombs) - but the higher mechanical adjacent string crosstalk on the Ghosts resulted in much worse Alt tuning warbles  - so i  reinstalled the original LR Baggs Piezos 

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For warbling, double check the pick-up height to the strings.

If they're too close, they can pull on the strings, and in Model

mode, it induces a warble effect that the piezos can pick up on.

 

And yes, it is exaggerated when in an Alt Tune tuning.

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Ok, despite common sense as prescribed by well intentioned sources of information, I used a sanding bit in my dremel tool to sand off about .5mm from each side of the A,D,G and B piezos, and off the "inside" edge of the two Es. So all up I have around 1mm extra gap in between piezos. See pics of one of my strats pre-sanding, and the other post-sanding. I found this to be both quicker, and actually much easier that trying to sand by hand, with the piezo having limited mobility due to it's still being attached to the guitar by it's wiring. Light touch - easy job really, once you get the hang of it.

The aural results are attached - for some reason (as I've already mentioned elsewhere), it seems really obvious when I use an open G tuning. This one is using a Tele with a P90 near the bridge through a Blackface 'Lux Vib with a bit of bite dialled in - think "Keef". Other detuned choices sound far less "off" to me.

 

In the attached recording I have played each string individually, the first instance of each note is the pre-sanded sound, the second is the post-sanded sound, to make it easier to hear the difference. It's only when picking individual notes, that any of these sound "off". As a chord, they're totally acceptable.

 

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Pics and sound samples - couldn't figure the attachment process before... :rolleyes:

post-863899-0-08920100-1441258771_thumb.jpg

post-863899-0-49253100-1441258792_thumb.jpg

post-863899-0-68825800-1441258816_thumb.jpg

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Make sure you have turned down the string volume on all strings to compensate for the much higher output of the Ghost Piezos.  I tried my Variax 500 first without doing this and it was way overdriven and it did not sound right at all.  I went to about 50% to get a reasonable output that is probably about where the old piezos were.

I turned mine down to 70% - to my ears that was about the same output as the L R Baggs output. I may experiment a bit with this though. Having said that, I can't see how it could affect the "bleed" problem - maybe someone with a bigger brain than mine could explain any possible improvement in this strange phenomenon.

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I just looked at the pix here and compared to my Variax 500 and I would say that mine are too close also!  Almost touching.  I don't really use alternate tunings on my 500 so maybe I would not notice the cross talk as much.  I agree that they should not be touching!  I also don't want to mess with mine so they will stay as is for now.

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I just looked at the pix here and compared to my Variax 500 and I would say that mine are too close also!  Almost touching.  I don't really use alternate tunings on my 500 so maybe I would not notice the cross talk as much.  I agree that they should not be touching!  I also don't want to mess with mine so they will stay as is for now.

Agreed - if you don't use alternate tunings, leave well enough alone.

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I have been ruminating on the issue. I figured it's only when neighbouring strings have a different detune value added to it's processed signal, that the cross talk is really obvious - as is the case when you set up an open G tuning. When all strings are dropped a full tone (or the like), it's not noticable, as all processing is the same on each string, and any cross talk is processed in the same way.

As the audio snippets show, even though there is a decent gap between saddles now, the problem still exists, so there are vibrations travelling (I guess) down through the height adjustment screws, throught the steel plate the saddles are sitting on, and up through the neighbouring height adjustment screws, and into the piezo still. Thus the problem will probably never fully be resolved, only improved upon. :rolleyes:

Hopefully this helps others out with this issue, and feel free to add to the pool of info peeps!!

Now on to the second vax before tonights gig!!!

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There will always be some crosstalk since the vibrations will travel as you suggest.  It has to be small for alternate tunings to not be negatively affected.  Crosstalk won't be a big deal with standard tunings since all of the signals are left at their natural frequencies.  It is easy to measure the crosstalk by fooling with the string volumes.  If you turn off the E string and pluck it, anything that comes through is coming through one of the other piezos.  If you use capo tunings, then again crosstalk should not create any bad sounds since all of the strings are shifted the same relative amount. 

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Recently changed my stock Line6 piezos to Ghost set. With a every other guitar part, for sure. Now I have Warmoth Custom build instead of Variax Standart.

Good news that I have 2TEK bridge and never experienced any kind of bleedings or warbles in Alt tune.

 

I decreased the Strings Volume settings in Workbench software from 100% to 61%, otherwise my Lester looks like digital overloads at high punches. (On a clean line sound without amps).

Anyone experience about yours settings of gain to match "before-ghost" output

 

I don't have nearby "true strat or tele or LP" to plug in my Helix and finetune.

May be I can do it approximately, but prefer to stay realistic and clear.

 

I created 2 banks with a Neutral Body, to play my guitar without modelling, and this way I need to reduce Volume till 38%, to make my guitar with Lester pickups modelling being similar gain with 61% Lester. WTF?

 

IMG_20190216_123812.thumb.jpg.5a562c1cc81bb579274dabd65a104f0d.jpg

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Old Variax does not have mag pups, just piezo pick-ups. JTV, Standard and Shurikens have mag pups.

With old Variax, Alt Tune bleed is what's called "dual tone effect",... hearing standard tune from the string,

while hearing Alt Tune thru the amp. They clash.

 

The stuff about pick-up height to strings would apply to JTV, Standard and Shurikens and not old Variax.

Wanted to be certain to have both covered in the post, sorry for any confusion.

 

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