Removing wart from GK-2A and GK2 to connect the GKs to newer Kit preamp

Started by luca9583, September 09, 2022, 03:23:43 PM

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luca9583

Hi all

I have a 7 string instrument with GK-2 and GK-2A mounted on the body, running a VG and VB-99.

I'd like to route for GK kits in the guitar instead but i was thinking maybe i could just disconnect the pups from the warts and connect them to a KIT instead.

Having said that it probably makes more sense to remove the whole
lot and just install a full kit from scratch, but i was curious if anyone has done this and also if Roland supplies just the preamp, output connector and GK volume direct.

gumtown

From my recollection the GK-2A pickup plug in header is a different pitch/size to the GK-3 and GK-KIT-3.
The GK-2A pickup also has a flatter  but fixed radius, where the GK-3 pickup is slightly more raised in the middle, but the pickup poles have an adjustable radius from the center.

The GK-KIT-3 comes with a GK-3 pickup too.

Once you get the GK-KIT-3, it might be best to first look at the two pickup sizes and check the GK-3 is going to be a good fit.

Worst case is you might need to get the GK-2A pickup connector plug replaced with the smaller GK-3 one.
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luca9583

Quote from: gumtown on September 09, 2022, 03:53:38 PMFrom my recollection the GK-2A pickup plug in header is a different pitch/size to the GK-3 and GK-KIT-3.
The GK-2A pickup also has a flatter  but fixed radius, where the GK-3 pickup is slightly more raised in the middle, but the pickup poles have an adjustable radius from the center.

The GK-KIT-3 comes with a GK-3 pickup too.

Once you get the GK-KIT-3, it might be best to first look at the two pickup sizes and check the GK-3 is going to be a good fit.

Worst case is you might need to get the GK-2A pickup connector plug replaced with the smaller GK-3 one.

Thanks very much. Yeah i've already got a few KIT-3s so will compare.

It's actually an instrument with narrower than standard string spacing, but the GK-2A, even if it isn't lining up with the strings very well, still gives me great separation for alt tunings which is pretty cool.

Am i right in thinking the spacing of the GK-2A is ever so slightly narrower than the GK-3A? Shame they didn't make these with adjustable spacing.

I messaged both Proix and Stick about making me a modded 7 string GK with narrow spacing but they didn't sound interested.


admin

Quote from: luca9583 on September 09, 2022, 08:04:13 PMThanks very much. Yeah i've already got a few KIT-3s so will compare.

It's actually an instrument with narrower than standard string spacing, but the GK-2A, even if it isn't lining up with the strings very well, still gives me great separation for alt tunings which is pretty cool.

Am i right in thinking the spacing of the GK-2A is ever so slightly narrower than the GK-3A? Shame they didn't make these with adjustable spacing.

I messaged both Proix and Stick about making me a modded 7 string GK with narrow spacing but they didn't sound interested.

review this Hex PU string Spacing document
https://www.vguitarforums.com/smf/index.php?action=downloads;sa=view;down=41

And this thread about modification for improved string spacing
https://www.vguitarforums.com/smf/index.php?topic=410.0




luca9583

Quote from: gumtown on September 09, 2022, 03:53:38 PMFrom my recollection the GK-2A pickup plug in header is a different pitch/size to the GK-3 and GK-KIT-3.


@gumtown if i remove the GK2A's wires from it's white header, can those wires then be fitted into the GK3 Kit's header?

gumbo

Yes...sort of..

GK2A header is JST 8-pin 2mm pitch PH Series

GK3 header is JST 8-pin 1.5mm pitch ZH Series

You will find that you will need the appropriate size (female) crimp pins on the end of the conductors, as the male pins differ in size between the PH and ZH size...

....they DO NOT interchange.

Cheers,
Peter
Read slower!!!   ....I'm typing as fast as I can...

luca9583

Quote from: gumbo on December 13, 2022, 11:34:11 PMYes...sort of..

GK2A header is JST 8-pin 2mm pitch PH Series

GK3 header is JST 8-pin 1.5mm pitch ZH Series

You will find that you will need the appropriate size (female) crimp pins on the end of the conductors, as the male pins differ in size between the PH and ZH size...

....they DO NOT interchange.

Cheers,
Peter

Thanks for confirming. Could the wires from the GK3 Kit be soldered to the GK2A pickup itself?

gumbo

Quote from: luca9583 on December 14, 2022, 03:06:19 AMThanks for confirming. Could the wires from the GK3 Kit be soldered to the GK2A pickup itself?

With difficulty, and with potential damage to the circuitry from excess heat.

...and once you do that, the pickup is permanently connected to the mainboard...this might make for some installation problems...

The knock-off crimp pins are available on ebay from Hong Kong...not exactly rocket science OR a million whatever-is-presently-passing-as-currency in your neck of the woods..

BUT you also need the appropriate crimping pliers to do the job properly.

If you just want to hack into stuff and don't care what the cr@p it all looks like, just go to your local electronics-franchise-of-choice and buy some (small) single-pole male/female inline connectors (8 singles, or 4 doubles or two lots of four-pole) and cut each loom in two and use these connectors to link all the conductors from the two looms together in the appropriate and required order...

That way at least, you have a system that still allows you to disconnect the pickup from the mainboard in order to get the whole thing installed without standing on your head or knocking the whole mess off the kitchen table and inadvertently feeding it to the (waiting) household cat.

...just saying....

...or simply cut the two looms as described above, and solder the two opposing bits together...tape it up, shrink-sleeve it or whatever, and you end up with something that at least unplugs from the mainboard and keeps the cat hungry...
Read slower!!!   ....I'm typing as fast as I can...

luca9583

Thanks again @gumbo..much appreciated.

To keep things simple, i just opened up a GK2A, unsoldered the wires, opened up a GK3 from the kit and unsoldered those wires, and then soldered those Kit 3 wires to the GK2A. It work really well.