VGuitar Forums

GK-13 Reference Knowledge => GK Mag Hex (GK-2A,GK-3) => Topic started by: Elantric on March 06, 2011, 01:18:40 PM

Title: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Elantric on March 06, 2011, 01:18:40 PM
There are many folks who find the default GK-3 / GK-2A mounting with the large cable emerging at the low E side  to be awkward.

I play in a surf band lately ,and its near impossible to play a fast run on the Low E (like "Miserloo") and pick near the  bridge due the GK-3 pickup being in the way! 

(https://lh3.googleusercontent.com/-TGiETqx5OeM/TiEURCwBrSI/AAAAAAAABzY/t1uzwK0GVKs/s640/IMG_0733.JPG)
(https://www.vguitarforums.com/smf/index.php?action=dlattach;topic=359.0;attach=15573;image)
As a solution, the newer Roland Gear ( VG-99, GR-55) include a GK Direction parameter,which lets you install the hex pickup "reversed" -  but the older gear does not have this function!

I have taken my GK-3 apart and Hex  pickup wires terminate in One white 8 pin Female header ( 6 string signals, Ground, and shield) This plugs into a Male 8 pin Male header on the GK-3  PC board.

With care, the  6 Hex  pickup signals on the 8 pin Female header can be re-arranged. No soldering required.

This allows me to mount the Hex pickup with the cable emerging at the high E side, and set the GK Direction parameter on newer 13 pin gear to "Normal" and maintains full backward compatibility with all my legacy dinosaur 13 pin gear, (VG-8,GR-30, etc) 

This operation can be performed on Roland GK-2, GK-2A, GK-3, GK-3B, Yamaha G1D, Axon AIX-101, Fishman TriplePlay hex mag pickups - including the internal "kit" versions.

Below is a pic of the unmodified internal GK-2A pickup header. The Black wires on the far right  are Ground and Shield - leave those alone.





BEFORE
(https://s6.postimg.cc/w064p7zb5/GK3_PUP8_POSPlug_zpsb3e3aaf9.jpg)

Roland Internal 8 position PU Header (Left to Right)
8. Brown.........String 1 - high E
7. Red............String 2 - B
6. Orange.......String 3 - G
5. Yellow........String 4 - D
4. Green..........String 5 - A
3. Blue............String 6 - low E
2. Black...........Ground.
1. Ground Shield.



Use a sharp pointy X-Acto Hobby knife, or a needle, and Gently "lift" the lower edge of each white plastic finger in the red box to remove the wire with crimp metal contact away from the white plastic header. Do this for the 6 wires on the left - leave the two Black wires on right in their current location.

 
AFTER
Re-insert the 6 pickup wires in the new reverse sequence below to allow the GK-3 PU to be mounted "reversed".
(https://s6.postimg.cc/q0idlkeip/GK-2_A_hex_PU_header_JPG_thumb_zpsca7514aa.png)


Then you can install the GK-3 Hex PU Reversed like this:(not my guitar!)
(https://www.vguitarforums.com/smf/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_i1Fyixcp6lk%2FSss_WA5x0MI%2FAAAAAAAABGg%2FYIZkO8vs6xg%2Fs400%2FIMG_4380.JPG&hash=194c40353629cf872e5c193477a3031667c067ee)



More details on this same topic here too:
https://www.vguitarforums.com/smf/index.php?topic=3865.25 (https://www.vguitarforums.com/smf/index.php?topic=3865.25)


https://www.vguitarforums.com/smf/index.php?topic=568.msg18147#msg18147 (https://www.vguitarforums.com/smf/index.php?topic=568.msg18147#msg18147)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: RS on March 06, 2011, 04:04:43 PM
My internal GK3 just came in from backordered and I have to pick it up in another State in the next 30 days. I intend to have my luthier install (if possible) that sucker into one of the Les Pauls I own. If not possible, I will return that GK3.

I have read that there (might) be issues installing it on a Les Paul. This information is really good! I will give this link to the luthier. Any other info (and I've seen the 'Les Paul' thread) is/would be great!
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Elantric on March 06, 2011, 04:49:10 PM
If you principally use COSM pickup modeling,  an alternative Gibson style hex pickup which can be mounted in a Les Paul at the Bridge Humbucker position and use the Roland Internal GK Kit preamp parts is explained here:
https://www.vguitarforums.com/smf/index.php?topic=3115.0 (https://www.vguitarforums.com/smf/index.php?topic=3115.0)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: mostlyjazzer on August 21, 2011, 05:55:37 PM
I've got my gk-3 open and looking at the multi connector to inverse them.
What tool or technique do you use to remove/rearrange the colored wires? a needle? I'm concerned of forcing pull out
and damaging the end,

MJ
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: mostlyjazzer on August 21, 2011, 06:02:49 PM
looks like a needle works
MJ
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: rafaelrebolleda on August 22, 2011, 03:23:11 AM
Quote from: PLexxiTronic on March 06, 2011, 04:04:43 PM
My internal GK3 just came in from backordered and I have to pick it up in another State in the next 30 days. I intend to have my luthier install (if possible) that sucker into one of the Les Pauls I own. If not possible, I will return that GK3.

I have read that there (might) be issues installing it on a Les Paul. This information is really good! I will give this link to the luthier. Any other info (and I've seen the 'Les Paul' thread) is/would be great!

I've just installed a GK3 Kit on a Les Paul:
https://www.vguitarforums.com/smf/index.php?topic=4309 (https://www.vguitarforums.com/smf/index.php?topic=4309)

Here's a flickr set with the project:
http://www.flickr.com/photos/rafaelrebolleda/sets/72157627270046857/ (http://www.flickr.com/photos/rafaelrebolleda/sets/72157627270046857/)

It's clear to me that reverse-mounting the pick-up is the best fit; I'm using a VG-99 so I didn't rework the cables like mentioned in this thread, but I confirm it's very easy to do it if you need backwards compatibility.

Go for it!
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: alanw57 on November 14, 2012, 12:14:41 PM
Quote from: mostlyjazzer on August 21, 2011, 06:02:49 PM
looks like a needle works
MJ

How, exactly, do you do it?  Where do you insert the needle?
Thanks,

Al
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: drjoness2001 on November 14, 2012, 12:20:52 PM
Quote from: rafaelrebolleda on August 22, 2011, 03:23:11 AM
I've just installed a GK3 Kit on a Les Paul:
https://www.vguitarforums.com/smf/index.php?topic=4309 (https://www.vguitarforums.com/smf/index.php?topic=4309)

Here's a flickr set with the project:
http://www.flickr.com/photos/rafaelrebolleda/sets/72157627270046857/ (http://www.flickr.com/photos/rafaelrebolleda/sets/72157627270046857/)

It's clear to me that reverse-mounting the pick-up is the best fit; I'm using a VG-99 so I didn't rework the cables like mentioned in this thread, but I confirm it's very easy to do it if you need backwards compatibility.

Go for it!

There is another compelling reason to reverse wire the GK-3, even if you are not using a VG-99: compatibility with the RMC input filter.

I have a guitar with a Floyd Rose trem, and it tends to generate a slight low-end rumble that can confuse the VG-99. The RMC filter installed inside the VG-99 takes care of this problem, but the filters on the RMC are specific to the strings.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: gandolf on April 08, 2013, 06:27:38 PM
Hi,

Just picked-up a 2nd hand electric guitar  just to use with the GR55 (so i usually play bass...and was previously trying to use my 6string acoustic for guitar mode...but that was not really working for me)....

anyway, just wanted to understand why the standard way to install the GK3 pickup is with the cable leaving from the top of the pickup....i;m thinking it's better to mount it with the cable leaving toward the bottom (facing to the ground)....as it seems more out of the way in this "reverse" direction...?

But as i;m not usually a guitar player, so maybe i;m missing the reason as to why it's better from the top? This seems to be the way most pics have it showing.

Any advise appreciated.

Cheers!
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: riggy on November 24, 2013, 11:57:35 AM
Hello

I recently bought a GR-55 and an Internal GK-3 Kit.  I have looked at the videos on youtube at:

Roland GK-Kit Installation Video Part #1 (http://www.youtube.com/watch?v=NTC_Exf4e4Y#ws)

Roland GK-Kit Installation Video Part #2 (http://www.youtube.com/watch?v=hGAJLg6nhIk#ws)

Does it matter which way the pickup cable comes from: ie. does it have to be at the top of the bridge or can it be placed the other way round?

I hope that makes sense... sorry if it doesn't!

Thanks for reading, Rich
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: JolietJake on November 24, 2013, 12:45:39 PM
Hello Rich

You can mount it either way. The default way is with the cable coming out the top. However if you want the cable coming out the bottom you can change the orientation within the GR-55 settings.

Colin
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: gandolf on November 24, 2013, 05:35:04 PM
I have the cable going down on both my guitar and bass:  i think it looks much neater ....and also i don't "sense" the cable is in the way..

When i installed the GK on my guitar though, i found i needed to shim up the Top/Low E end of the pickup....so you might want to check you have even spacing between strings and pick-up.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: datsunrobbie on November 25, 2013, 05:56:23 AM
One thing to keep in mind - If using the guitar with older gear it may not work properly with a reversed pickup. The GR-55 can do it, but I don't think a VG-8 or GR-1 has the option.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: JolietJake on November 25, 2013, 10:22:57 AM
Even if your equipment does not have an option to reverse the pickup it is possible to dismantle the connector and reorganise the order that way. There is instructions on this site for doing this too.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Elantric on November 25, 2013, 10:27:18 AM
QuoteEven if your equipment does not have an option to reverse the pickup it is possible to dismantle the connector and reorganise the order that way. There is instructions on this site for doing this too.

Correct!
GK-3 - Electrical Mod for reverse mounting the pickup
https://www.vguitarforums.com/smf/index.php?topic=3365.0 (https://www.vguitarforums.com/smf/index.php?topic=3365.0)



BEFORE
(https://s6.postimg.cc/w064p7zb5/GK3_PUP8_POSPlug_zpsb3e3aaf9.jpg)
Roland Internal 8 position PU Header (Left to Right)
1. Brown.........String 1 - high E
2. Red............String 2 - B
3. Orange.......String 3 - G
4. Yellow........String 4 - D
5. Green..........String 5 - A
6. Blue............String 6 - low E
7. Black...........Ground.
8. Ground Shield.



Use a sharp pointy X-Acto Hobby knife, or a needle, and Gently "lift" the lower edge of each white plastic finger in the red box to remove the wire with crimp metal contact away from the white plastic header. Do this for the 6 wires on the left - leave the two Black wires on right in their current location.

 
AFTER
Re-insert the 6 pickup wires in the new reverse sequence below to allow the GK-3 PU to be mounted "reversed".
(https://s6.postimg.cc/q0idlkeip/GK-2_A_hex_PU_header_JPG_thumb_zpsca7514aa.png)


Then you can install the GK-3 Hex PU Reversed like this:(not my guitar!)
(https://www.vguitarforums.com/smf/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_i1Fyixcp6lk%2FSss_WA5x0MI%2FAAAAAAAABGg%2FYIZkO8vs6xg%2Fs400%2FIMG_4380.JPG&hash=194c40353629cf872e5c193477a3031667c067ee)



More details on this same topic here too:
https://www.vguitarforums.com/smf/index.php?topic=3865.25 (https://www.vguitarforums.com/smf/index.php?topic=3865.25)


https://www.vguitarforums.com/smf/index.php?topic=568.msg18147#msg18147 (https://www.vguitarforums.com/smf/index.php?topic=568.msg18147#msg18147)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: gumbo on November 26, 2013, 04:56:46 AM
...and if, through the intervention of an alien life-form, the little plastic connector (on the end of the wires) falls to bits in your hand while doing that mod...I have replacements..  ;D 
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: riggy on November 28, 2013, 05:28:03 PM
Hi Guys

Many thanks for all of your comments.  I thought that I would need to use all of the cable depending on the position of PCB but eventually we found that there was a small gap right behind the scratch-plate so we managed to get the pickup into the default position by cutting a small channel out with the router to hide the wires in!!

So that is all of the cutting done (except for the holes for the S1/S2 buttons) have never needed to cut a 15mm hole before so might have to buy a new drill bit if my Uncle doesn't have one I can borrow.  The next step will be the soldering which leads me to consider asking what may turn out to be a very dumb question  :-[  ??? (please see my next thread):

https://www.vguitarforums.com/smf/index.php?topic=9996.0 (https://www.vguitarforums.com/smf/index.php?topic=9996.0)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: gumbo on November 29, 2013, 02:00:05 AM
Quote from:  riggy on November 28, 2013, 05:28:03 PM
Hi Guys

Many thanks for all of your comments.  I thought that I would need to use all of the cable depending on the position of PCB but eventually we found that there was a small gap right behind the scratch-plate so we managed to get the pickup into the default position by cutting a small channel out with the router to hide the wires in!!

So that is all of the cutting done (except for the holes for the S1/S2 buttons) have never needed to cut a 15mm hole before so might have to buy a new drill bit if my Uncle doesn't have one I can borrow.  The next step will be the soldering which leads me to consider asking what may turn out to be a very dumb question  :-[  ??? (please see my next thread):



https://www.vguitarforums.com/smf/index.php?topic=9996.0 (https://www.vguitarforums.com/smf/index.php?topic=9996.0)




When you're sourcing a 15mm drill bit, consider getting a "Forstner" bit....  nice clean edge to the hole, won't wander off the (necessary!) pilot hole that you drilled first...    ;)

There are details on this type of drill bit in the Installation Instructions for my Synth-Linx jacks...let me know if you'd like a PDF copy of that to give you a better idea..   PM me with a valid email address that will accept a 4MB PDF...

Cheers,
Peter
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: JolietJake on November 29, 2013, 04:17:51 AM
Hello Riggy

If you dont want to drill 2 15mm holes into your guitar you could always purchase a single ON-OFF-ON mini toggle switch to do the same job.
They are very inexpensive and look identical to the toggle switch supplied in the internal kit. The only difference is they spring back to the centre OFF location. You click it one way for up and the other way for down. Essentially they are 2 switches in a single switch body.

Several people (including myself) have done this.

https://www.vguitarforums.com/smf/index.php?topic=359.msg62171#msg62171 (https://www.vguitarforums.com/smf/index.php?topic=359.msg62171#msg62171)

Cheers
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: whippinpost91850 on November 29, 2013, 09:14:33 AM
If you can't find a Forstner bit a "Brad point bit"  would be next best choice.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: riggy on December 02, 2013, 05:44:42 PM
Well, when I mentioned in passing that I was looking for a 15mm drill bit, little did I know the kind of discussion that would ensue! 

Unfortunately Peter, by the time I had received your message, Amazon had already dispatched the 15mm brad point that I had ordered for £5:

http://www.amazon.co.uk/Bosch-2609255212-160mm-Point-Diameter/dp/B004WO6E00/ref=lh_ni_t?ie=UTF8&psc=1&smid=A3P5ROKL5A1OLE (http://www.amazon.co.uk/Bosch-2609255212-160mm-Point-Diameter/dp/B004WO6E00/ref=lh_ni_t?ie=UTF8&psc=1&smid=A3P5ROKL5A1OLE)

But I had considered a forstner as well.  Is this what you meant:

http://www.amazon.co.uk/Bosch-2609255285-Forstner-Drill-Diameter/dp/B004WO6GHG (http://www.amazon.co.uk/Bosch-2609255285-Forstner-Drill-Diameter/dp/B004WO6GHG)

At the time this seemed like it was far too meaty especially as we only wanted get to put two holes in the scratch-plate - I mean that's no big deal, right?  In actual fact it's hard to say - this simple task was made a whole lot more difficult because we had gone from having two nice pilot holes straight into a 10mm drill bit (simply because it was the biggest that we had.)    :-[  If you have a look at the link to the brad point shown above you can see that the center of the bit is pointed, whereas the rest of our 15mm hole was dependent on the point being in the right place.  We ended up placing a piece of dowel inside the hole, marking our center with the point of the bit and drilling out the dowel as well as the scratch-plate, all the while avoiding damaging the switches and wiring.  Like I said we made life more complicated for ourselves by being somewhat impatient, I guess.  I don't know if a forstner bit would have solved this little blip or not but it does prove to some extent that whatever you are into, you always want to check the internet and the forums for extra information, no matter how trivial.  You'll likely find that someone, somewhere has asked the same question or faced the same problem and put the details online.

Colin, thanks for your comment but I found the perfect place for the pair of them with the other switches and I have to say they really look the part - there's nothing to suggest they were not part of the guitar from the beginning!  8)

Rich
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: gumbo on December 03, 2013, 12:29:09 AM
Good 'save' there with the dowel...
...something similar to what I would have done in the circumstances.. ::)

While I agree with Colin's thoughts on the On/Off/On momentary switch as far as saving real estate, I personally like the 'feel' of the push buttons better, and find that I can handle multiple actuations much more easily and positively..   maybe that's just me.. :-\

Whatever...hope you'll have a lot of fun with your (now) GK guitar!!!

cheers,
Peter
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: whippinpost91850 on December 03, 2013, 11:02:46 AM
Rich, I built Custom guitars , and modified thousands , for over 30 years and I mentioned the brad point as that my  go to bit for most of that time. Good going on the dowell that's what I would have told you to do. Congrats on gettin her done
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Headless68 on May 24, 2014, 02:26:45 AM
I am in the process of building a dedicated GK guitar at the moment - I have a GK Kit to install & I am going to reverse the pickup (so the extra length is not where your palm sits at the bridge) - I see the setting in the GR-55 to set the pickup in reverse mode but before I fit it I just wanted to check with the group that there are no other considerations or gotchas to think about?

Cheers
Phil
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: montyrivers on May 24, 2014, 04:38:46 AM
Since you're doing an internal installation, you can repin the hex pickup's 7 wire harness that plugs into the summing board.  This is actually very simple.  You just need to gently "lift" the tab on each of the 6 pins from the plastic connector using a flat screwdriver or scalpal and slide them out.  Just click them back into place in reverse order.  Leave the 7th grounding wire alone.

Now you can use your guitar with any gk device without any threat of complication, and no cutting or soldering involved!

Do a quick forum search for the related post by elantric for visual aid if needed.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Mrchevy on May 24, 2014, 05:39:42 AM
I have my external GK3 Hex pickup mounted in reverse ( wire on the bottom side) and set to reverse in the GR55. No problems and out of the way.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: adamlee011 on August 23, 2015, 05:56:49 PM
Since you guys seem to have messed with the guts of these some, any idea what to do about this short of calling Roland for a pickup? I installed a kit in an ibanez s premium. No easy task. I had it perfect but didn't like the angle of the regular bridge pickup so I went to straighten it all out and one of the wires came out of the gk pickup. At the pickup itself. So I opened it just enough to look inside and solder it back best I could without tearing the pickup wide open or burning the paper thin circuit board if you can call it that. Now I have all 6 magnets picking up sounds but crosstallk galore. The tuner on the vg99 shows all the strings lighting up when you hit one. Same with the sensitivity settings, though the one you're plucking meters strongest. Any idea how I can fix it?
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: adamlee011 on September 12, 2015, 01:25:55 PM
fixed it. just had to clean and resolder all of the wires at the pickup which was a pita but fyi can be done if you're patient and careful. When I have the time and motivation i'll post the work i did on the ibanez s 970 in it's own thread. that was one heck of a job. especially for me since i have no experience with most of what it entailed. i photographed most of it at each stage.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Headless68 on September 12, 2015, 02:54:34 PM
Glad you got it sorted - those wire look very close together

I just did the wire swap on the GK3 kit connector - once I figured out how to get the pins out ( the pic seems to be missing from the beginning of this thread on what that looks like) - can now use the VG8 with this guitar

Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: adamlee011 on September 12, 2015, 03:10:21 PM
Yea I did it too from the get go just for backward compatibility. I have a vg-88 and 99 but the 88 lately has bass duty (just compression and eq for my bass before it hits the amp really)  Always intended to mount it upside down. Doesn't really make sense to me not to. It was rather simple once you figure out how to get the first one out. It allowed me to snake into the control cavity without widening the existing hole too. No real choice but to take the harness off. Soldering the wires to the thin board in the pickup is another story. I actually (purposely) melted the plastic under the pickup where they each run into their own little hole in order to have room to work /see what I was doing. Here's a quick shot of the finished s. I'll have to get around to doing a step by step narrative /pictorial.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: ConstruKction on September 12, 2015, 06:07:30 PM
Quote from: Headless68 on September 12, 2015, 02:54:34 PM
Glad you got it sorted - those wire look very close together

I just did the wire swap on the GK3 kit connector - once I figured out how to get the pins out ( the pic seems to be missing from the beginning of this thread on what that looks like) - can now use the VG8 with this guitar

In addition to the recently acquired VG-99, I managed to find a nice Roland GR-30, so I had no choice but to conduct the modification. I used a needle to lift the plastic piece that clamps the pin. They seem quite fragile but actually they're flexible.

Done in ten minutes, and the GR-30 is outstanding when it comes to tracking. While not perfect, it doesn't complain about my low C string as much as the VG-99. Ha-haaaaa! No wonder Fripp still uses it.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Ciaron on October 07, 2015, 09:32:22 AM
Apologies if this has been covered before...

I've just got myself a GK-3 which I'll be using with a newly acquired VG-8EX.

The 'donor' guitar is self built so I don't really have any concerns about drilling holes etc, but I'm a little concerned about the hex cable position on the upper bout of the guitar and whether or not it's going to get in the way of my playing.

Thus, my question is, is there a specific reason why the hex pickup can't be mounted in reverse? IE with the hex cord emerging from under the high E string, rather than under the low E string?

Thanks in advance.

Ciaron
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: admin on October 07, 2015, 09:57:07 AM
Modern Roland/Boss systems since 2007 include a choice in the GK Type user setting for "Reverse"  - which allows you to mount the GK-3 hex PU with the Wire emerging downward 

But older systems (VG-8, VG-88) do not have this functionality

Many modify their GK-3 by swapping the 6 string signal wires so you can use all generations of GK 13 processors

Read details above

Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Ciaron on October 08, 2015, 07:31:41 AM
Quote from: admsustainiac on October 07, 2015, 09:57:07 AM
Modern Roland/Boss systems since 2007 include a choice in the GK Type user setting for "Reverse"  - which allows you to mount the GK-3 hex PU with the Wire emerging downward 

But older systems (VG-8, VG-88) do not have this functionality

Many modify their GK-3 by swapping the 6 string signal wires so you can use all generations of GK 13 processors

Read details above

Thanks for this, very much appreciated  :)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: howarddavidp on September 24, 2017, 06:18:00 PM
It's thread NECRO time!!! :)

I just bought a GP-10, which DOES have the reverse feature.  However, I kept my GR-33, so I needed to use this thread and the information here to reverse the wires.

Once again, the pictures and the info stands the test of time, as it is 2017 and I just reversed my GK-3 on a homemade EVH strat.  I will try and get some pictures posted.  I also bought a brand new GK-3 for my Ibanez RG920MQM, but I might consider getting the KIT since this is a nice guitar and it is worth it to me.

Thanks again to the original poster, this was super easy to do.

David
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: gumbo on September 25, 2017, 04:08:32 AM
Quote from: howarddavidp on September 24, 2017, 06:18:00 PM
It's thread NECRO time!!! :)

I just bought a GP-10, which DOES have the reverse feature.  However, I kept my GR-33, so I needed to use this thread and the information here to reverse the wires.

Once again, the pictures and the info stands the test of time, as it is 2017 and I just reversed my GK-3 on a homemade EVH strat.  I will try and get some pictures posted.  I also bought a brand new GK-3 for my Ibanez RG920MQM, but I might consider getting the KIT since this is a nice guitar and it is worth it to me.

Thanks again to the original poster, this was super easy to do.

David


PM me for details if you might also NOT want to dig a dirty big hole in the edge of your nice guitar in order to install the standard Roland 13-pin jack...   ...the drop-in pre-wired Synth-Linx Jack only needs a 5/8" (round!) hole   ;)  ...and only costs a measly 40USD + 5USD shipping all the way from sunny(!!) Australia...

Cheers,
Peter

Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Headless68 on September 26, 2017, 02:11:33 AM
I would totally recommend Peter (aka Gumbo's) 13 pin socket - I just installed one - MUCH less intrusive to the guitar and a lot easier to install - very high quality build ( in my opinion significantly better than OEM )

Headless :-)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: MrSparkle on October 03, 2017, 08:42:51 AM
Sorry to bump an old thread, but I've got to do this reverse mod on one of my Parker Flys that had an internal GK2a installed (reverse-mounted) by the previous owner. GR-1 doesn't have the reverse option so I'm only able to partially enjoy the G-string (no pun intended).

I'm gonna have some new pickups and pots installed anyway, so I was thinking of just taking it to the shop instead of messing under the hood since I'm a little clumsy with electronics, but I'm trying to gauge whether the GK wire mod is simple enough for me to do without damaging something. Seems like it's just unclipping and re-attaching the wires? The catch is that section is really small and I'm hesitant getting in there.

I mean, I've changed iPhone batteries, but when it came to changing the GPS chip, let's just say I lost 10% of my touch screen's touch capabilities after the operation.  :-X
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: Headless68 on October 22, 2017, 11:22:42 AM
its simple - just be careful as the GK wires are small so don't use force on them
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup
Post by: chrish on January 16, 2018, 12:31:59 PM
This rewiring of the connector will solve two problems for me for my internal gk-3 install.

One is the reason stated for  better pickup mounting option

And two, by taking all the wires out of the connectors including the ground, I'll be able to slide the wires through a smaller opening.

Thanks for the ideas.
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Maimroid on March 04, 2023, 11:58:32 AM
Hello!
I've been scouring this topic for a quick answer to getting the PU header pulled up off of the circuit board so I can begin the reversal process. I'm nervous that I might damage things If I just gently yank it.
This is what I have:

https://drive.google.com/file/d/1pI2-pHBeove3Xyecx_c_MfZumAbTUI4z/view?usp=share_link

Hope the link works.
There are 2 small holes on each side that look like release tabs but pressing them and prying the header up seems incredibly difficult.
Thank you!!

Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: admin on March 04, 2023, 12:05:55 PM
Gently/slowly pry up vertically  with small flat blade screwdriver under tabs on each end of cable mounted 8 pin header

MS Power Point instructions
https://www.jst.com/wp-content/uploads/2020/09/ZPD.pps

MS Power Point Viewer
https://www.lifewire.com/pps-file-2622184

Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Maimroid on March 04, 2023, 01:25:45 PM
Will give it a go. Thank you!!
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: gumbo on March 04, 2023, 03:32:10 PM
To expand on 'admin's excellent earlier answer....


"There are 2 small holes on each side that look like release tabs but pressing them and prying the header up seems incredibly difficult."

...that is because they were never intended to be pressed ...there is basically NO 'give' in the barbs that interlock with the holes in the side of the header, as they are simply raised sections that are moulded (as one) on the sides of the female connector.

To ease the release of the connector from the header (while prying upwards via the tabs on each end) place a VERY fine knife blade (automotive feeler gauge / razor blade ) down the SIDE of the header between it and the connector) and marginally move the side of the header away from the barbs on the connector.....this will reduce the hold on the barbs within the two locking holes.

Apply lifting force ONLY via the two tabs on the ends of the connector....DO NOT pull on the wires themselves.

Once the connector is released from the the header, you can then start to release the individual wires by using a FINE knife blade to GENTLY lift each locking pawl on the connector JUST FAR ENOUGH to enable you to withdraw the wire along with its female crimp connector.

Pulling these up abruptly or straining on them can cause them to break...if that happens YOU WILL HAVE TO REPLACE THE ENTIRE 8-PIN PLASTIC CONNECTOR.....it is a JST Series ZH 8-pin connector....and yes I have a ton of them here in Australia...but that's not going to help you much at the time.

Pay attention to the orientation of the crimp connector to the locking pawl as you withdraw it ....don't force anything and document which side of the crimp faces the locking pawl.

Only remove the six wires that connect to the individual poles of the pickup...these are the ones that need their order reversed.

Leave the wires for pins 7 & 8 still attached to the plastic connector as they have to remain in their original positions.

BEFORE you re-insert crimps 1 - 6, GENTLY press down the locking pawls that you previously lifted to release the crimp connectors so that the pawls can again do their job correctly and prevent each of the six pickup wires from becoming accidentally disconnected in the future.

HTH


Needless-to-say....when the modification to the female connector circuits is completed, correct and full re-plugging back into the header is essential to make things work again..loose or intermittent connections to these circuits will plague you until the job is done properly.


Ask questions if you want more information


Cheers,
Peter






Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Headless68 on March 04, 2023, 03:44:27 PM
looking back on this thread I did this mod in 2014 - Reading this just made my palms sweat again :-)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: gumbo on March 04, 2023, 03:49:11 PM
Quote from: Headless68 on March 04, 2023, 03:44:27 PMlooking back on this thread I did this mod in 2014 - Reading this just made my palms sweat again :-)

Don't pet sweaty things.....   ;D
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Johnny2hats on March 11, 2023, 10:10:05 PM
Hello - I saw this thread refreshed so I thought I mite be a good place to ask.
I have the GK-2a attached to my guitar (not an internal mount job) with a GI-20 GK-MIDI Interface. I cant find the option to reverse the pickup direction nor have I found any mention of it in the manual.

as far as the midi pickup goes.. playing with the cable by the low E string is proving impossible for me.
Does the mod cable you sell (if you still have any..) work for the gk-2a external version?

I was thinking that If I found a male and female 13pin din socket I could just rewire them myself and have this 13pin midi adapter cable running inbetween my GK-2a and the gi-20 interface. seems like the most non-invaseive way to do it with an external rig.
do you offer anything like that? :)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: admin on March 11, 2023, 10:28:48 PM
Reverse PU direction is Not supported on pre 2007 Roland/Boss GK 13 processors

That's why the DIY internal  hardware 8 pin divided pickup  header pin rewire-Sequence reversal is prefered-as described at top of this thread  nobody is selling an adapter here- its an easy DIY mod

Same procedure for GK-2A, Yamaha G1D, etc

Then you can just select normal PU direction on all GK Processors

(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRcIeRyB7rXMHox9kPKkjpf9Q9glWk0ZybAJA&usqp=CAU)
GK-2A -OBSERVE WHITE 8 PIN HEADER
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Johnny2hats on March 12, 2023, 03:59:38 PM
Thanks for the clarification. I just saw gumbos display picture and thought it mite be somthing that was sold..  I just cant find any explanations for how to do it for the external GK-2a.
also thanks for the photo - I havnt seen inside the gk-2a before but there is the header - looks pretty straight forward thanks

...I was thinking If i could make my own 13pin din cable - and just swap pins 1 to 6 to reverse the order. That way - my gk-2a is still original and I cant mess anything up inside the gk-2a.
I am pretty new to this however - can you think of any reason why that would not work?

http://johnp.net/projects/guitar-synth/roland-pinouts.html
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: gumbo on March 13, 2023, 06:41:51 AM
Quote from: Johnny2hats on March 12, 2023, 03:59:38 PMThanks for the clarification. I just saw gumbos display picture and thought it mite be somthing that was sold..  I just cant find any explanations for how to do it for the external GK-2a.
also thanks for the photo - I havnt seen inside the gk-2a before but there is the header - looks pretty straight forward thanks

...I was thinking If i could make my own 13pin din cable - and just swap pins 1 to 6 to reverse the order. That way - my gk-2a is still original and I cant mess anything up inside the gk-2a.
I am pretty new to this however - can you think of any reason why that would not work?

http://johnp.net/projects/guitar-synth/roland-pinouts.html

Yes, I still make Synth-Linx Jacks...nearly ten years after they were first released on this Forum...
https://www.vguitarforums.com/smf/index.php?board=181.0

...BUT...that will not help in this case.
Changing the order of the pickup signals at the 13-pin jack WON'T get you there, because there is internal (frequency-limiting) filtering of each of the six individual string signals WITHIN the electronics of the GK mainboard itself...you need to 'feed' each string circuit of the GK mainboard with the signal frequency it was designed to accept.


...what you need to do is to reverse the order of the 6 cables carrying the individual pickup signals WHERE they enter the GK pickup mainboard (on either the Internal kit OR the External kit)

The photos that are shown earlier in this thread of the 8-pin (pickup-to-mainboard) connector are relevant to BOTH Internal and External Roland hex pickup installations....WITH THE CAVEAT that the GK2A pickups used a slightly larger 8-pin multiplug (JST PH Series 2mm pitch) to achieve the connection, while the later GK3 pickups used the JST ZH Series 1.5mm pitch.

Since you are talking about modding a GK2A External pickup, that even easier because it just a matter of removing the screws that hold the two sides of the pickup housing together in order to gain access to the (larger PH Series) connector, which is even easier to manipulate as each circuit crimp is substantially larger and at 2mm centers instead of 1.5mm apart as in the later GK3 pickups.  ;) 


The way to achieve this is detailed in my post of a few days ago in this thread....if you can't understand that, or need more information, you are welcome to ask here or PM me.

HTH

Cheers,
Peter
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Maimroid on March 18, 2023, 01:43:36 PM
Thank you GUMBO for the thoughtful and precise instructions. I just finished the surgery and it works like a charm. I was also able to see that there was some bad soldering of a additional green wire that had come away from its post on the synth/mix/mag switch. No wonder I wasn't getting any sound from the mag pickups. (however the 1/4 inch jack doesn't put out a signal any more either) Well that's a different subject anyway.
Again huge thanks to the community at VG forums!!
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Johnny2hats on April 22, 2023, 05:52:27 PM
Quote from: gumbo on March 13, 2023, 06:41:51 AM...BUT...that will not help in this case.
Changing the order of the pickup signals at the 13-pin jack WON'T get you there, because there is internal (frequency-limiting) filtering of each of the six individual string signals WITHIN the electronics of the GK mainboard itself...you need to 'feed' each string circuit of the GK mainboard with the signal frequency it was designed to accept.


Thanks very much for answering this Gumbo its much appreciated - something I never would have figured out lol and I would have wasted alot of time..

Thanks to all the great info on these forums I managed to follow the instructions and reverse my GK-2a pickup direction with no problems at all.

2 best bits of advice I read - when removing the header from the the PCB - slide a razor blade between the connector and the header to relieve the 2 little nubbins that lock it in.
and then when releasing the individual wires - i used needle/ syringe (one that i use for applying flux when soldering) to gently pry open those little tabs.

was all easier than I expected and made my setup SO much more usable - I can palm mute and dampen the strings again without worrying about that stupid cable poking out :) thanks again everyone
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: Elantric on February 12, 2024, 01:19:55 PM
GK-2 uses 8-pin JST PH Series (2.0mm pitch)

GK-3 uses 8-pin JST ZH Series (1.5mm pitch)

GK-5 uses 8 pin  JST "SR (1mm pitch)
Title: Re: GK-3 - Electrical Mod for reverse mounting the pickup ( GK, Tripleplay, Antares
Post by: gumbo on February 13, 2024, 05:26:55 AM
Quote from: Elantric on February 12, 2024, 01:19:55 PMGK-2 uses 8-pin JST PH Series (2.0mm pitch)

GK-3 uses 8-pin JST ZH Series (1.5mm pitch)

GK-5 uses 8 pin  JST "SR (1mm pitch)

Thanks Steve..
Yeah...I forgot to add that one to the mix...good that it's all in once place finally !
...although I will say that dismantling the 1.0mm pitch components is not for the faint-hearted or shaky-of-fingers... ;D

Cheers,
Peter