Can GK-3 PU be too close to the bridge??

Started by Headless68, January 09, 2015, 12:20:51 AM

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Headless68

I have just made a new scratch plate and mounted a GK kit as close to the bridge as possible leaving a gap for intonation adjustments - this gives a range of 7.5 mm to 9mm for the GK settings, however when I come to put in the parameters on the GP-10 the lowest figure you can select is 10mm - does that mean I have installed it too close an 10mm is the minimum distance?

Headless68

#1
Pic example


papabuss

FENDER STRATOCASTER (1974); BRIAN MAY RED SPECIAL; VG 99; GR 55; Yamaha DX 7

Music was my first love and it will be my last (JOHN MILES)

Elantric

#3








Be sure you are measuring "GK PU Distance"  from Center of GK PU to the point where the string leaves the Bridge Saddle / or center of Kahler Roller.

For a GK-3 on a Guitar, I would be sure its at least 10mm away. 20mm is probably Optimal.

If the GK PU is set closer than 10mm - it will be sensing a smaller / shorter excursion of any vibrating string, with resulting drop in  the output level of the GK PU .


You can compensate by boosting the "GK Sensitivity" to a higher number - but this results in higher susceptibility to hiss and noise when using DSP COSM Guitar Modeling, with a likely requirement to enable the "COSM N.S. ( Noise Suppressor Gate) to tame the hiss  - but know there will be a resulting loss of picking dynamic range response.


If the GK PU is set too far away from the bridge saddle ( more than  30mm) - it will be sensing a higher / larger excursion of any vibrating string, with higher susceptibility of adjacent string cross-talk anytime you bend strings during Rock/Blues solos - and that creates poor tracking / ghost notes.


Headless68

Will move it forward 10mm - I am getting drop in output volume

Thanks guys

Headless68

FYI - the extra 10mm made all the difference - wont do that one again :-)

Tony Raven

Oh, wow -- am I glad I found this thread.

I was about to mount a GK-3 to a nice clone SG, all intentions to butt the pickup right to the bridge... ::)

10 mm to 20 mm. Got it.

Fusion

I just installed another GK-3 on my Les Paul using the bridge bracket mount and I have 2 saddles measuring 9 most are 10 and a couple 11 so I am right at the closest position which bugs me if that is a problem as the bracket comes with the GK-3.
Any greater spacing and I would probably hit my bridge HB pickup mounting ring.
I just got this installed so i have not yet had a chance to set the sensitivity or run it through the paces. I am thinking a piezo type would have zero spacing on some designs so wondering if this is really such a big deal. Seems pondering the spacing that the greater the spacing the more apt to get bad triggering from much wider string vibration issues. Just thinking out loud but it seems the tighter less vibration range of the string to the pickup signal might be better for tracking????

How are you other LP users doing out there?
"Long ago in days of old when magic filled the air..."

Tony Raven

In this respect, there's no basis for comparing piezo saddles to magnetic pickups. For starters, the spacing between a piezo & the string's break point is identity (0.00... mm).

That "10 mm" is likely a heuristic -- engineers love insane precision to a gazillion significant digits; marketers like nice neat round numbers.

I really doubt that 7 mm will make a HUGE difference, but if it's any help, remember that the LP/SG scale length is a little shorter than the Strat's, so I could rationalise that comparable strings on the former will swing a little more freely. 8)

As you point up, the included mount is a compromise to fit into a gap that's common but hardly standardized.

Putting the GK closer to the bridge runs quickly into diminishing returns: as you reduce the overtone series, the pickup's output drops even more quickly. By the time you achieve a "perfect tone," output has been buried in background noise.

Headless68

Regards the LP install - I have used the supplied bracket with a 335 and had no issues - I suspect the problem I had on my custom install was the 7.5 mm range where there was a noted drop off so close to the bridge

mooncaine

Thanks for that! I think I needed it. This explains why my fave guitar sounds a bit harsh and noisy compared to others with GKs on. Bummer. It's too narrow for a GK.

Quote from: Elantric on January 09, 2015, 12:00:11 PM
Be sure you are measuring "GK PU Distance"  from Center of GK PU to the point where the string leaves the Bridge Saddle / or center of Kahler Roller.

For a GK-3 on a Guitar, I would be sure its at least 10mm away. 20mm is probably Optimal.

If the GK PU is set closer than 10mm - it will be sensing a smaller / shorter excursion of any vibrating string, with resulting drop in  the output level of the GK PU

.....

If the GK PU is set too far away from the bridge saddle ( more than  30mm) - it will be sensing a higher / larger excursion of any vibrating string, with higher susceptibility of adjacent string cross-talk anytime you bend strings during Rock/Blues solos - and that creates poor tracking / ghost notes.


bea

Thanks. I am aware of all that.

The main problem is that is a lot of hassle to put the pickup further away from the bridge: i had to drill holes to hold the springs of the GK3 pickup I would need to close them and drill new ones. And that on a guitar wit a fresh finish and without a pickguard.
It'll need a lot of creativity to change that without additional damage to the guitar.

The only way for me is to see how it works with the fat strings. Furthermore it looks as if i had to increase the distance of the pickup form the strings because of too too much attraction by the magnets of the GK3. At least the low C(E) and F(A) strings will show this with the heavy flatwounds. In contrast to the .009 strings.

What remains? I'll try and see what happens. If there are problems (and i expect there will be)  i know about possible and probable causes and possible cures.

Tony Raven

I went to Shapeways.com, which is a 3D-printing/sales site for artists & inventors. One member ("Coll Mall") makes these little shims for use with bridge humbuckers --


http://www.shapeways.com/product/X6ABHAJM8/roland-gk-3-guitar-midi-pickup-attachment?optionId=57538273

(downside: the s/h fees are a bit steep.)

I've got one sitting right here, & am slooooowly getting around to installing it. All-plastic, so less likely to mess the guitar up (much). Those two little nubbins are intended to provide threaded posts for the GK's base; you need to buy your own hardware. (I'm thinking about a thin foam strip to provide height.)

Can be mounted as you see it, or you spring for a neck-height pickup ring, cut off most of the long side, then mount that atop this shim.

I cannot yet vouchsafe that proper height can be achieved with an LP-type, but it looks like it'll be fine on a Strat.

I'm still a bit uncomfortable sticking a GK so close to a humbucker's magnets... but it's a start.
________________

Here's a simpler option, more recent, a few dollars less.


http://www.shapeways.com/product/PS2C2TCND/gk-saddle-6mm-deep?optionId=60998094
________________

To get both proper height AND distance on an LP, this might be the only reasonable solution.


http://www.shapeways.com/product/935FWV9XP/roland-gk-pickup-mount-quick-release-version?optionId=43362210

You get one casting, which you have to separate into two main pieces. One mounts atop the pickup ring --


The other bolts to the GK.


You then have the luxury of being able to take the whole GK assembly off & put your guitar in a case. :o


Someone mentioned that the pickup mount could be stuck/bolted to an acoustic's top, thus giving the same between-gig flexibility.

Does it work? Dunno. Tests welcome. ;) Overall, seems like a cheap (well, <$30) way to bring much-needed flexibility to the GK.

alexmcginness

VG-88V2, GR-50, GR-55, 4 X VG-99s,2 X FC-300,  2 X GP-10 AXON AX 100 MKII, FISHMAN TRIPLE PLAY,MIDX-10, MIDX-20, AVID 11 RACK, BEHRINGER FCB 1010, LIVID GUITAR WING, ROLAND US-20, 3 X GUYATONE TO-2. MARSHALL BLUESBREAKER, SERBIAN ELIMINATOR AMP. GR-33.

admin

#14
QuoteDo you get improvement if you move the pickup placing away from the bridge where crosstalk gets worse?



http://www.buildyourguitar.com/resources/lospennato/index.htm


GK-3 PU works best when each internal PU can respond only to its intended string, and not its neighboring strings too.


( as can occur when bending strings)



- Simple physics - The string has much less side to side excursion closer to the bridge.

Placing the GK-3 further away from the bridge places the GK Hex PU closer to the path of the adjacent vibrating string and raises the crosstalk from adjacent strings.


GK-3 PU  placed farther away from the bridge means the A,D, G, B,  strings will experience picking up "TWO wrong frequencies" from adjacent strings now in its pickup path. The GP-10 will warble,  due to "garbage in = garbage out" , that can be mitigated when the GK-3 PU is located closer to the bridge

( But not too close, else the GK-3 output signal levels will be too weak

https://www.vguitarforums.com/smf/index.php?topic=13322.0

GuitarBuilder

Quote from: admsustainiac on April 08, 2018, 11:10:16 AM


http://www.buildyourguitar.com/resources/lospennato/index.htm


GK-3 PU works best when each internal PU can respond only to its intended string, and not its neighboring strings too.


- Simple physics - The string has much less side to side excursion closer to the bridge.

Placing the GK-3 further away from the bridge places the GK Hex PU closer to the path of the adjacent vibrating string and raises the crosstalk from adjacent strings.


GK-3 PU  placed farther away from the bridge means the A,D, G, B,  strings will experience picking up "TWO wrong frequencies" from adjacent strings now in its pickup path. The GP-10 will warble,  due to "garbage in = garbage out" , that can be mitigated when the GK-3 PU is located closer to the bridge

( But not too close, else the GK-3 output signal levels will be too weak

https://www.vguitarforums.com/smf/index.php?topic=13322.0

Based on my experience with the Cycfi Nu, crosstalk is still acceptable in the bridge humbucker position. 
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

mooncaine

Quote from: GuitarBuilder on April 08, 2018, 02:39:32 PM
Based on my experience with the Cycfi Nu, crosstalk is still acceptable in the bridge humbucker position.
Even if you do some crazy-wide Frank Zappa bends?

GuitarBuilder

"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

mooncaine