GK-3 - Mods - Distance to string, radius mods, potting

Started by Elantric, February 25, 2008, 09:09:59 PM

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flingus

Hello,

I've been lurking around this board since I bought the GK-3 and VG99 two weeks ago and I've been finding the information here very helpful.

That being said, I just had a couple of questions in regards to the GK-3 pickup. I'll list what I'm working with then go on to the question..

I installed the GK-3 on a Music man Axis Super Sport, with the double sided tape. The bridge is fixed, no floating tremolo or anything like that. Guitar is intonated correctly, new strings, and I'm playing through a Mesa Simulclass 2:90 and a stereo 4x12. I set the sensitivity low as suggested in the forum, and I've also put in the saddle to pickup measurements, and scale length of the guitar as well.

I've tried to get all the strings 1mm from the magnets in the GK3 pickup. Currently, I have the bottom E, A, D, and G strings pretty spot on. The B and high E string are closer than 1mm though.

I'm experiencing two problems with the VG99 that I havent really been able to fix over the last two weeks.. One problem is, any of the Bass guitar presets sound pretty darn fake. Sounds exactly like my effects processor trying to detune my notes instead of emulate a actual Bass guitar. (If that makes sense) Some of the presets even sound like a bad detune pedal or something. Are the bass presets just bad, or could this have to do with the way I mounted my pickup?

Second problem I'm experiencing is, and this is only on some presets, my high E is PIERCINGLY loud. Which is why I'm thinking about trying to adjust my string to magnet height. It's the closest of all my strings to the magnet so, that would make sense.. The only odd thing is, that it is only happening on certain presets. Others you cant notice a difference at all. So, I was thinking of either trying to get the distance to be greater for just the B and E strings, or lowering the sensitivity for these two strings, or maybe assigning those presets where I notice a problem to a GK3 setting that can mellow out some of those highs somehow. 

First question is, should I even worry about this? Should I just set the sensitivity a little lower for the B and E strings and be good to go?

Second question is, what in the heck are these measurements listed for the neck radius? 184R, 250R, 300R etc.. I looked on Ernie Balls website and I cant find a measurement listed for the neck that is anywhere close to any of these numbers.

I haven't tried adjusting the yoke for the pickup yet but, it's my understanding that if I do, all the magnets will move so I dont think this would help me since 80% of my strings are at the 1mm mark.

Any help would be greatly appreciated!

Thanks!


Elantric

#51
A couple thoughts

* Back off the height of the GK-3 PU so it is no closer than 1mm WHEN YOU FRET AT THE 22nd FRET!

* Yes - the factory VG-99 presets suck - particularly the Bass emulations.

* Verify that your "GK Settings" in the system area are being used for each patch with the "too high volume E string". Remember each VG-99 Preset  / Patch can call up a different GK Setting on the fly,  so its possible those patches are calling up the factory default GK PU setting Values, and not your own settings.

Quotewhat in the heck are these measurements listed for the neck radius? 184R, 250R, 300R [the the GK-3 Installation Manual]
These are Metric
http://www.metric-conversions.org/length/millimeters-to-inches.htm

184R mm = 7.24409 inch Radius
250R mm = 9.84251 inch Radius
300R mm = 11.8110 inch Radius

http://www.music-man.com/instruments/guitars/axis-super-sport-bfr.html
Axis Neck Radius:
10" radius (25.4 cm) = 254mm Radius = 254R
 

flingus

Thanks Elantric.. I'll have to see if I can remove some of the material for the spacer under the pickup for only the treble side. I don't think I'll need to adjust the yoke but, it appears my guitar neck is 250mm radius. What threw me off about the manual was it just put an 'R' after each measurement. I understand what they were trying to convey though, 250mm Radius. I wonder how the pickup yoke comes from the factory? Fully extended? Anyway, I dont want to change the yoke if I dont have to since again, most of my strings are the perfect height from the magnets..

I'll verify where the presets are pulling the GK3 settings from. I just recently figured out that you can assign presets to certain GK3 settings so, I'll have to check that out.

I'll have to say, I like a lot of the presets . It's really just the Bass presets and some of the acoustic presets that annoy me. I would figure if the VG99 can make my guitar sound like a freakin organ, it could handle sounding like a Bass easily enough. I guess I'll have to tweak the Bass settings and see if I can get something more realistic.  I dont know how to explain it but, it really sounds like a guitar trying to sound like a bass. The acoustic presets are 'ok' but, some of them really have a booming sound when doing heavy strumming involving the low E. The nylon is ok as well but, I wont get into that. Seems some of those issues have been addressed many times. :)

Thanks again.

aliensporebomb

There are many excellent presets on this board you can download that totally will make you erase EVERY preset in the VG-99 that Roland supplies.  Seriously.
My music projects online at http://www.aliensporebomb.com/

GK Devices:  Roland VG-99, Boss GP-10, Boss SY-1000.

Elantric

Also all MusicMan Guitars have a "Compound Fretboard" - which makes the 22nd fret more like a 12 inch radius   

The big deal with the GK-3 "Yoke" radius adjustment to to attempt to duplicate the same radius on your GK-3 as your guitar has at its highest fret on the fingerboard (many Musicman's have 24 frets)


hazeshawn

The Loctite actually did the trick, it's been over a year and no stripped screws! :)
Notice how I remain calm. I do this because I am The Shawn!

Guitars:
20011 Gibson Les Paul Double Cut Classic
2009 Fender American Deluxe V-Neck Stratocaster
2003 Gibson Les Paul Classic

"Quality"... not "Quantity"!

FreeTime

Just a 'lil brain-nudge to remind you NOT to just put any old small screw into the end-cover of your GK3. Mine fell out and even after an exhaustive search and rescue mission with a giant speaker magnet all is  lost. No big deal, before I dispose of old electronics I strip off anything useful and I did find a screw with the right pitch and diameter, but even though it fit thread-wise it was just a smidgeon too long and pinched the wires underneath, I found this out during a semi-important christmas gig; Silent night just doesn't sound right without a G-string; now I get to spend a cursing-filled hour with miniature tools and a magnifying glass :)

dead_lizard

I carefully attempted the same repair after getting sick of my d string going intermittent.
It all worked pretty well, though there were a few tense moments. Not being very experienced with a soldering iron and only having one pair of hands made it quite difficult. I would also suggest using a really good soldering iron with a fine tip and/or disconnecting the pickup from the rest of the circuit board. I chose to do neither of these and finally got away with it....or so i thought. when i plugged it in, my d was back on line, but my high e missing. I had damaged the winding when removing it from the sticky plastic/glue at the end of the board. So be especially careful with this step. Also has anyone else stripped the thread of their radius screw? I think they should make it a hex key or phillips head or something more resilient.

celestmark

#58
Yea, just noticed my GK3 lost that cover screw and ended up pulling the red (b) wire out!
I don't have the tools or patience to fix this unit.  :o

Searching now for a knowledgable tech to solder it!

Also, I found the info to reverse the pickup configuraton with my GR-55 so the wire goes the other way to avoid this from happenning in the future: https://www.vguitarforums.com/smf/index.php?topic=3365.0  :P

arkieboy

Just noticed I lost my GK3 screw :-(

Anyone know what the dimensions and thread of the screw are?

Steve
Main rig: Barden Hexacaster and Brian Moore i2.13 controllers
Boss SY1000/Boss GKC-AD/Boss GM-800/Laney LFR112

Other relevant gear: Line 6 Helix LT, Roland GR-33, Axon AX100 MkII
Oberheim Matrix 6R, Supernova IIR, EMu E5000, Apple Mainstage, Apple Logic, MOTU M4

arkieboy

Quote from:  arkieboy on March 04, 2012, 08:44:34 AM
Just noticed I lost my GK3 screw :-(

Anyone know what the dimensions and thread of the screw are?

Steve

Roland says its an M2x3.  Plentiful on eBay  ;D

Steve
Main rig: Barden Hexacaster and Brian Moore i2.13 controllers
Boss SY1000/Boss GKC-AD/Boss GM-800/Laney LFR112

Other relevant gear: Line 6 Helix LT, Roland GR-33, Axon AX100 MkII
Oberheim Matrix 6R, Supernova IIR, EMu E5000, Apple Mainstage, Apple Logic, MOTU M4

tekrytor

I just bought a few as spares from the Roland parts department for $1 each plus $6 shipping. It's a bit pricey for just a tiny screw, unless you can combine shipping with other parts.
SY-300/BeatBuddy/VoiceLive 3/GR-55(v1.50)/33/1/50/700/VGA-7/V-Bass, Yam-G10, GPK-4, DIY X-Bee HighlyLiquidCPU "Cozy-Lil-Footie", FCB-1010, other MIDI stuff, Godin Freeway SA and various other GK equipped controllers, Sonar X1, Audacity, KXstudio, Misc devices

BenT

#62
Are there any advantages to replacing an installed GK-2 pickup with a GK-3 pickup? Is there an actual improvement in the GK-3's electronics?
--------------------
Benjamin Robert Tubb
Using the VG-8EX, GR-1EX and VG-99
with FC-300, GR-1EX, GI-10, US-20.
Main guitar: Carvin DC-400 with GK-2A pickup

Jim Williams

#63
I believe they are the same electronically except for the adjustable curve, retractable cord and 1/4 inch guitar input. it also comes with mounting plate for Les Paul style bridges.
Skype: (upon Request)

Everything from modeling to the real deal, my house looks like a music store.

Elantric

#64
QuoteAny notice when you play the older models with the newer GK3 you have to crank up the sensitivity and levels? Apparently the GK3 has lower output than the GK2s.

Correct - the GK-3 has a lower output.

The GK-2A has a higher output, and explains  why most Piezo GK systems have a "hot" output too - as the gain and output sensitivity for most Piezo systems were based upon the GK-2A output level.



Mag Hex PU Measurement comparison

https://www.vguitarforums.com/smf/index.php?action=downloads;sa=downfile&id=41


From Roland
http://www.roland.com/support/article/index.cfm?q=faq&p=GK-3&id=1832145

QuoteQ.Are the GK-2, GK-2A, and GK-3 pickups compatible with all GR-series guitar synthesizers equipped with a 13-pin GK pickup connector?

    A.Yes, they are all compatible. However, there are slight differences in the output voltage produced by the GK-2, GK-2A, and GK-3 pickups, which can affect the playing feel of the guitar synthesizer system. For this reason, you should adjust the input sensitivity setting on the GR-series unit specifically for each GK pickup model.



Compare

GK-2A Schematic (double click the pic to expand)



GK-3 Schematic (double click the pic to expand)




GK-3 has an additional unique function which is not implemented / supported by any other 13 pin gear.

This is in regards to pin #9 on the GK 13 pin cable.


GK-3 (Pin#9) Voltage Range: (GK  = 1.56V / Mix =  1.04V / Guitar =  0.52V
GK-3B (Pin#9) Voltage Range: (GK  = 4.48V / Mix = 3.96V / Bass = 3.44V


All prior pickups (GK-2A, Axon Aix-101, Yamaha G1D, RMC, Graphtech Ghost) have no  connection on Pin #9. Even most GK 13 accessories leave a no connection for Pin #9. (Roland US-20). The exception is the RMC Fan-Out box which provides a spare 1/4" jack wired to Pin #9 for supporting custom installations.

Many custom builders find that reliability improves if Pin #9 is employed as a redundant Ground signal, since the weak link in the Roland 13 pin DIN implementation is relying on only One Ground connection using the large round circular shell of the male 13 pin DIN plug as the only Ground connection between the guitar and the processor. The weakest link in this scenario is the shell electrical contact on the female 13 pin DIN jack.

Many of these "GK-IN" Female jacks have a very poor contact with the Male DIN plug's Shell Ground connection. Mid song during a live show if you hear gargles static noises coincident with moving the GK Cable - you know its time for a short spritz of Caig Deoxit D-5 contact cleaner


make direct contact with the internal Ground Contact deep within Female DIN 13 Jack (GK INPUT) on your VG-8, VG-88, VG-99,GR-55, GP-10 Hex COSM, RACKVAX.


I do it once a year

The ramifications of an intermittent Ground Connection anywhere along the GK 13 pin cable can be damaging  - and its less of a problem for the other 13 pin gear , where an intermittent 13 pin cable ground for Guitar to MIDI, PCM Synth box (i.e. no COSM GUITAR MODELING - specifically the  Roland GR-1, GR-09,GR-20, GR-30, GR-33) the CPU that triggers MIDI events typically can recover from a temporary loss of Ground  - not so with the VG-8, VG-88, VG-99,GR-55, GP-10  -  temporary loss of Ground on the later will send the sound of shaving with the tip of a 1/4" cable plugged into a Marshall Stack into your Amp/PA  and that type behavior can ruin the chances of your acoustic guitar / tabla player duo getting re-hired. It ruins the show everytime if when your GK Cable is touched / Moved / vibrated/ impacted by the rhythmic cycle of the drum riser,or sitting on top of a subwoofer on a live stage.


Its typically one two things - a 13 pin cable that has crimped (and not soldered) ground (shield)wire inside the male DIN13 plugs on each end of the Gk Cable. check that if contact cleaner doe not deliver instant positive results. Turns out that direct Exposure to the air we all breath tends to corrode all electrical contacts. Thats why the Top tier electronic companies use Mil-Spec components, with oxygen free contacts - like a $100 LEMO Connector
http://www.lemo.com/catalog/ROW/UK_English/f_series.pdf

http://www.lemo.com/en/rugged-connector/f-connector?domain=%5Bterm_node_tid_1%5D

QuoteSwitzerland
LEMO S.A.
Chemin de Champs-Courbes 28
P.O. Box 194
CH-1024 Ecublens, Switzerland

Tel : 00 41 21 695 16 00
Fax : 00 41 21 695 16 02
Mail : info@lemo.com

Roland doesn't  use that type - - instead it employs Circular DIN 13 connection
http://en.wikipedia.org/wiki/DIN_connector

A DIN connector is an electrical connector that was originally standardized by the Deutsches Institut für Normung (DIN), the German national standards organization. There are DIN standards for a large number of different connectors, therefore the term "DIN connector" alone does not unambiguously identify any particular type of connector unless the document number of the relevant DIN standard is added (e.g., "DIN 41524 connector"). Some DIN connector standards are:
DIN 41524, for circular connectors often used for audio signals
DIN 41612, rectangular connectors used to connect plug-in cards to a back plane or motherboard
DIN 41652 D-subminiature connectors used for computer data and video
In the context of consumer electronics, the term "DIN connector" commonly refers to a member of a family of circular connectors that were initially standardized by DIN for analog audio signals. Some of these connectors have also been used in analog video applications and for digital interfaces such as MIDI or the IBM AT computer keyboard (later PS/2 connectors for keyboard and mouse are Mini-DIN connectors). The original DIN standards for these connectors are no longer in print and have been replaced with the equivalent international standard IEC 60130-9.


The Roland  GK-13 Specification supplies only one Ground Reference connection for:

7 unbalanced analog audio signals (6 strings+Normal PU)

2 DC Voltage Controls ( GK-VOL) , Voltage Ladder Input (Pin#9 Selector Switch Status),

2 GPI Inputs ( S1, S2 momentary switches)

+7VDC Power

-7VDC Power

Thats all 13 pins - and a good Electronic Design engineer with a few years real world experience would tell you "Hey! You Forgot something!
They would have budgeted multiple Ground pins - with a separate Analog Signal Ground Reference, Digital Signal Ground Reference, Power Return Ground, RF/EMI Shield   

Yet every Guitar Center Salesman is still trained to call this a MIDI Cable


By contrast the older Roland  24 pin GR-300 , GR-700  a large "Rectangular Shell connection which employed 4 separate reliable Ground connections!

http://www.joness.com/gr300/24pin.htm

But back to the GK-3! The GK-3 features a control voltage on pin#9, which is mapped to respond to the current position of the 3 position "Guitar/ Mix/GK(Synth)" switch.

More details here:

https://www.vguitarforums.com/smf/index.php?topic=5259.0


More details about the GK-3 is here:
https://www.vguitarforums.com/smf/index.php?topic=4729.0


FWIW - my favorite GK hex pickup remains the Yamaha G1D / Axon AIX-101, for these reasons:


* Compared to a GK-3, the GID/Axon has a lower height profile which fits a wider variety of guitars than the larger GK-3 PU.

* The GK-3 can be prone to feedback on high gain VG-99 patches after you tweak and re-tweak the radius curve too many times. Wax dipping the GK-3 PU solves this.

http://www2.yamaha.co.jp/manual/pdf/emi/english/synth/G1DE.pdf

http://ftp.terratec.de/AXON/AIX103/Manual/AXON_AIX_103_Manual_1.0_GB.pdf








* For COSM Guitar Modeling systems, (VG-99, GR-55)  - a magnetic hex PU allows Palm muting, has a smoother tone for jazz/ blues/ rock, and has been tested to have a lower noise floor than Ghost Piezo systems. Ghost PU's tends to have more hiss and background noise than Roland  / Yamaha / Axon / RMC  pickups when used for COSM guitar modeling. Most Guitar to MIDI conversion systems mask this noise, but the noisier Ghost hex preamp can rear its ugly head when you connect up to  VG-99 and run high gain metal patches! 



And Read "GK-3 Pin#9 Explained

https://www.vguitarforums.com/smf/index.php?topic=5259.0


Measurement study comparing popular mag hex pickups



And Must Download this doc with pics comparing many Mag Hex Pickups by Roland, Yamaha, Fishman Tripleplay
https://www.vguitarforums.com/smf/index.php?action=downloads;sa=downfile&id=41


   

montyrivers

A good, albeit hideous fix is to just clean up the pickup real nice and just tape down the magnets with packing/scotch tape.  Only tape down the D and G strings if you have a guitar with a flat radius.  The tape adheres pretty well to the metal housing of the GK 3.  I'm serious about cleaning the pickup beforehand, though.  You'll be sealing it up for some wicked slime oxidation if it's dirty.  ;(

Other than that.  Grab some threadlocker.

I actually just ordered a tube of the low strength stuff.  Gonna see how it turns out.  It's a tiny screw, but just a dab of this gunk should keep it from going anywhere.

http://www.amazon.com/Permatex-24024-Strength-Threadlocker-Purple/dp/B000HBGHFY/ref=sr_1_6?s=automotive&ie=UTF8&qid=1332838841&sr=1-6

gumbo

BTW...

The tinyest (I mean that!) drop of nail polish also works as an efficient thread locker....     ::)

...a bit cheaper if you have someone in your vicinity who is already using the stuff... ;)
Read slower!!!   ....I'm typing as fast as I can...

arkieboy

good tip, gumbo!

I put the correct sized screw in and it popped out after a while.  I managed to beg several off our maintenance department and all had the same problem so I'm going to try nail varnish first, and then I'll increase the diameter of the screw.  I must have threaded it inadvertently :-(

Steve
Main rig: Barden Hexacaster and Brian Moore i2.13 controllers
Boss SY1000/Boss GKC-AD/Boss GM-800/Laney LFR112

Other relevant gear: Line 6 Helix LT, Roland GR-33, Axon AX100 MkII
Oberheim Matrix 6R, Supernova IIR, EMu E5000, Apple Mainstage, Apple Logic, MOTU M4

BenT

Elantric,
Thanks tremendously for your depth of comparison details. I also have an '87 Ibanez IMG2010 (24-pin) MIDI Guitar with an MC1 MIDI controller, but I haven't bothered to compared them (yet), since I've rarely used them anymore.

--------------------
Benjamin Robert Tubb
Using the VG-8EX, GR-1EX and VG-99
with FC-300, GR-1EX, GI-10, US-20.
Main guitar: Carvin DC-400 with GK-2A pickup

aliensporebomb

I might be losing my mind (well, not really) but I can hear subtle differences between the external GK3 that was mounted to my stratocaster before the middle of last week and the built in GK2A in my Roland Ready strat.  I used the same brand of strings and even mounted the same bridge (I transplanted it from one strat to the other) I had on the old strat. 

The differences seem to have an overall less bright affect even when I set the VG-99 to a GK2A or GK3 setting internally.  It's strange, the one thing I noticed is some of the guitar-to-midi tracking is actually better than that of the external GK3 but only on some patches.  It's not bad - some of the "distortion rock patches" sound more pleasant this way.

I created several variations of a new patch I've been working on and one of the patches that I set up to be a "high gain version" of the patch seemed lower gain on the GK2A even with the GK setting on the VG to GK2A or GK3.   For the GK2 I had to create an "extreme gain" version of the patch.

I notice the strings don't seem quite as close to the pickup as they did on the other strat even though the bridge height is identical (although the float height might be slightly different, hm, will look into this).  The pickup is possible recessed a little bit more than the height of my GK3 on my other guitar.

But it shows that MASSIVE audio differences can be seen from GK pickup type from GK pickup type and from guitar to guitar even when many variables are the same.  This explains why some peoples patches I've download didn't seem to get the "effect" that they did to the original patch writer.

I think I need to get a ruler to make sure the string heights are the same and then I can conclusively state if there are differences between two identical configurations.  But something is happening to make my ears go "that's odd.."

My music projects online at http://www.aliensporebomb.com/

GK Devices:  Roland VG-99, Boss GP-10, Boss SY-1000.

aliensporebomb

#70
OK last night I went and adjusted the height screws on the GK2A on the strat and set it to approximately the same height as the GK3 on my other guitar so the distance between the strings and the top of the pickup were the same.

Then I measured the distance from the hex pickup to the bridge in millimeters and set that up and it was pretty much the same on the other guitar and plugged it into the VG-99 settings.  Checked the scale length, pickup type, etc.

So same string gauges, same action height, similar guitars, same scale length, same GK cable.

I found that the GK2A and the GK3 seem to have their own tonal qualities - the GK3 seems more overtly bright, the GK2A seems to have a rounder tone in higher frequencies.  The GK3 seems to have a bit more output, the GK2A less overall gain.   You can counteract this by changing the internal gain settings but this was an eye opener but I'd need a scope to truly measure out a frequency response curve here.  My ears can tell the difference though.

So if you do a lot of distorted lead type sounds the GK2A seems to have a more rounded EQ for a more pleasant EQ curve for that type of thing.  The full range synthy type sounds I use sound more overtly bright on the GK3 and basses had a noticeable timbre change too - sort of a softer high end, not quite as overt.

So I decided to play around and noticed totally different EQ curves on each pickup when I changed the pickup type selector in the VG Editor - if I want the GK2A to be a bit brighter I can select "piezo" and it's almost as bright as the GK3.  If I select GK2A is seems less gainy overall - if I select either the GK3 setting or the piezo setting with the GK2 it seems gainier, if I try GK2A setting it has less overall gain.

I don't know if all GK2A pickups are like that or if all GK3 pickups are brighter and gainier like mine.  But it's interesting.
 
My music projects online at http://www.aliensporebomb.com/

GK Devices:  Roland VG-99, Boss GP-10, Boss SY-1000.

sytraxiplague

Hello! I'm new here and this has probably been asked before, so bear with me. When installing an internal GK3 kit, obviously the pickup can be placed backwards. I was told also that there's settings within the synth modules that will let you compensate for a backwards pickup. Does the GR50 let you do this or no? Thanks!

Elantric

#72
Only a select few processors allow for the reversal of the PU.

So on my own installs, if I reverse the PU, I also swap the internal electrical connections  so I can use with all 13 pin gear old and new.

sytraxiplague

Quote from: Elantric on May 13, 2012, 08:36:40 AM
Only a select few processors allow for the reversal of the PU.

So on my own installs, if I reverse the PU, I also swap the internal electrical connections  so I can with all 13 pin gear old and new.
Is that hard to do?

Elantric