GK-3 - string crosstalk and sympathetic vibrations

Started by Occams Razor, October 12, 2008, 08:03:47 PM

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Occams Razor

I've got my GK3 set to 40, 20, 20, 25, 25, 40

If I use a drop tuning anywhere from Drop D all the way to Drop Bb (Chevelle - The Clincher)
I get a sort of warble from my A string (mostly) especially when palm muting something like after the break in "The Pot" by Tool
I never get the true note, just a warble around the notes I'm playing, sometimes almost like a ring modulator
Also when palm muting something like "Black" by Sevendust, I don't really get the low B note on the E as much as a warbling also

Do I have to turn down the sensitivity even more?

I notice when I use the tuner that trying to tune ONE string will trigger a lot of the other strings as well
I've got my GK3 mounted with the Tune-O-Matic adapter

The input sure is HOT on the VG-99, I used to have some of my strings on the GK set to 100 on my VG-8, but only the string that I plucked would trigger
on the VG-99 plucking one string seems to trigger several around it.  :-\

Elantric

#1
Many T.O.M. bridge installs of the GK PU suffer from crosstalk.

Might want to consider the PAF PU Mounting ring mounting plate for your GK PU.
This decouples the GK-3 PU away from the vibrations from the Tune-o-matic bridge, which can be a source of induced crosstalk, even with Mag Pickups.

https://www.vguitarforums.com/smf/index.php/topic,40.0.html

https://www.vguitarforums.com/smf/index.php/topic,40.msg4629.html#msg4629

and consider adding Rubber String Dampers
https://www.vguitarforums.com/smf/index.php?topic=1397.0

Occams Razor

#2
Quote from: sustainiac on October 12, 2008, 08:14:54 PM
Many T.O.M. bridge installs of the GK PU suffer from crosstalk.

Might want to consider the PAF PU Mounting ring mounting plate for your GK PU.

https://www.vguitarforums.com/smf/index.php/topic,40.0.html

https://www.vguitarforums.com/smf/index.php/topic,40.msg4629.html#msg4629

Thanks for the links, it never dawned on me to try it on my guitar.  DOH!

Actually I can see why there would be so much cross talk, considering not only does the side of the hand rest there, but all of the sympathetic string vibration that just naturally goes through the bridge itself, must also send it on to the plate that the GK is screwed to.

BTW, do you EVER sleep?

EDIT: Looks like I might have to fashion one myself, as I have a high angled Pickup mounting ring, to accomodate the T.O.M.and the one on EBay is more for a Humbucker flatmount type
with a flatmount install

Elantric

#3
A few players damp the non speaking strings (between the T.O.M Bridge and tailpiece) by putting a piece of foam rubber under the strings back there. This helps too. Although by design, a T.O.M Bridge tends to be the center of a fulcrum for all the vibrating strings, and crosstalk is quite high.

What type of guitar is it?

Occams Razor

#4
Quote from: sustainiac on October 12, 2008, 10:42:05 PM
I few players damp the non speaking strings (between the T.O.M Bridge and tailpiece) with put a piece of foam rubber under the strings back there. This helps too. Although by design, a T.O.M Bridge tends to be the center of a fulcrum for all the vibrating strings, and crosstalk is quite high.

What type of guitar is it?

ESP 100 FM
http://www.americanmusical.com/Item--i-ESP-F100FM-LIST

I've got two more F50's I think I'm going to try and convert one of them from T.O.M. to flatmount by routing out the
neck angle in the neck pocket, I've already got a thread over in the Project Guitar forums about how to go about it.

99sense

#5
Hello all. I am new here.
I noticed something which may be helpful to others using the GK-3/VG-99.
I was experiencing a distortion using the GR-300 model, mainly on the open A string. After no success in locating the problem, I finally put the VG-99 output on an oscilloscope and noticed the distortion was in fact two different tones (the A string plus an additional tone).
While trying to locate the problem, I muted the other strings to eliminate them as sources of the second tone, but the problem persisted. Or at least I thought I was muting them. The problem was in fact another string vibrating, not at it's open pitch, but at a harmonic. Dampening a string only kills those tones (or overtones) which have an anti-node at the point of dampening. Tones that have nodes at the dampening point can ring out.
This is exactly what happens when you play a harmonic at the 12th fret. Touching the string at the 12th fret suppresses the open tone, being at it's anti-node, but allows the second harmonic (1 octave up) since it is at it's node.

Anyway, to get away from the technicalities, be careful to completely mute strings when troubleshooting crosstalk.

Also, a question:
Does anyone know of a method of reducing or eliminating string crosstalk on a tune-o-matic type bridge?

Brent Flash

#6
Quote from:  99sense on March 02, 2009, 06:06:51 PM
Also, a question:
Does anyone know of a method of reducing or eliminating string crosstalk on a tune-o-matic type bridge?
Welcome to the group 99sense!  :)

Yes, the GK-3 has to be acoustically decoupled from the tune-o-matic bridge. This has been discussed in another thread. I will have to look it up to point you to it.

Brent Flash

#7
You are talking about the mount that comes with the GK that fits on the tune-o-matic bridge?

I could not find the thread I was thinking of. If you are having trouble with this mount and cross talk, a number of members have reported that  the strings transfer their sound through the mount to the GK. I don't remember what they were doing to stop this other than not using this mount or they may have used some sort of gasket to try to isolate the pickup?

99sense

#8
Thanks
I believe the problem is that vibrations from the string being played are being transferred into adjacent strings. In other words, tones or overtones from the A string are being transferred to the E or D string through the bridge. The GK-3 pickup is of course then sensing this. Decoupling the pickup from the bridge would not help in this case, since the signal is already in the strings. This assumes of course that that the problem is in the bridge itself, not in the bridge to pickup coupling.

baranger1

#9
Most of the problem is transmitted through the body of the guitar.
If its a solid body guitar it may be worse.
What makes the solid guitar so popular is its ability recirculate its sting energy through the body back into the strings.
This causes "Sustain".
Sort of a internal feedback.

For the VG-99 to extract and create new waves forms from a guitar, the unit will completely square wave the guitar signal.
In lay terms this means they distort the signal to create extra harmonics.
(Picture several big muffs hooked together!)
This gives your guitar a signal with tons of things it never had from the start.
From there they can digitally filter stuff off and create new sounds.
Play it like you would a VERY distorted guitar.
Muting open strings or unused strings is a must!
What would you do if you had two Big Muffs connected together???
Bill

99sense

#10
"What makes the solid guitar so popular is its ability recirculate its sting energy through the body back into the strings.
This causes "Sustain"."

Ah, so the problem is not entirely in the bridge. Are some guitar body types better at reducing string crosstalk without giving up sustain?

"Play it like you would a VERY distorted guitar.
Muting open strings or unused strings is a must!"

This seems to be very true for the synth models, but the electric and acoustic models don't seem to suffer from poor muting like the synth models do.
My main point here also is that strings may not be as muted as one may think. Harmonics may still be sounding.

Brent Flash

#11
Quote from: Brent Flash on March 02, 2009, 06:16:31 PM
Welcome to the group 99sense!  :)

Yes, the GK-3 has to be acoustically decoupled from the tune-o-matic bridge. This has been discussed in another thread. I will have to look it up to point you to it.
Here is the tread I was trying to remember. https://www.vguitarforums.com/smf/index.php/topic,1202.0.html

99sense

#12
Thanks for the link.
If possible, I am going to try to mount the GK on the body or some type of pickup ring adaptor.
I can't use that particular one as it is not a PAF.

I had the same problem, though, after moving the GK off of the tune-o-matic mounting plate.
I have a heavier tune-o-matic somewhere that I might try if it will fit posts.

bryanz

This is ancient history, but Brent Flash, your link takes me back to this same topic.

Brent Flash

Quote from: bryanz on January 04, 2021, 03:34:58 PM
This is ancient history, but Brent Flash, your link takes me back to this same topic.
I am sure the two topics were merged at some point in time to keep things organized. Steve works hard at keeping things easier to find than they were at the beginning of this forum.

admin

#15
Reduce adjacent string crosstalk with GK-3

Verify the physical placement of GK Pickup is correct.
Refer to official documentation here
https://www.roland.com/V-Guitar/about.html
https://www.roland.com/V-Guitar/gk3-requirements.html



GK PU MOUNTING LOCATION
Verify there is roughly  20mm distance from GK PU to bridge. GK PU mounted Closer to bridge reduces the string output and not recommended. GK PU mounted further than 20mm increases susceptibility to adjacent string crosstalk - owing to wider excursions of each vibrating string further away from the bridge, which  may invade the adjacent middle four  A D G B string GK Pickup flux field regions- particularly when string bending blues styles.

GK PU HEIGHT : a general rule of thumb, use the included spacer to adjust the GK pickup height so that you have a space of about 1.0 mm between the top of GK pickup and the bottom of 1st and 6th strings when these strings are held down at the highest fret.


Lower the GK String Sensitivity

The default GK String sensitivity at 65 may be prone to crosstalk on some guitars

I always start by lowering this to the 25 to 35 range-for a balanced output across all strings.


There are no rules - get creative

On some situations with GK-3 pickup -try setting GK Type to one of the Piezo types - each type has a unique EQ curve and provides user Adjustable Bass and Treble controls


Don't forget to read the Setup docs for other GK Processors(VG-99 & GR-55)
- as the lower cost GP-10 lacks specific knowledge base reference documentation  that would cover same ground deep dive documentation provided for VG-99 & GR-55

Find these Docs in the DOWNLOADS link at top of our home page