Author Topic: GK Schematics  (Read 23099 times)

0 Members and 1 Guest are viewing this topic.

Offline mos6507

GK Schematics
« on: January 24, 2008, 04:56:01 AM »
Does anyone have schematics to the GK2/3 kit?  I'd like to isolate where pin 9 and the power lines enter into it.





« Last Edit: April 04, 2015, 02:48:51 PM by Elantric »

Offline Elantric

Re: Schematics
« Reply #1 on: January 24, 2008, 01:46:14 PM »


GK-2A Schematic



I understand formerly GK-2A "open spare" Pin 9 is now  used for a specific new function on the GK-3 :

Here's what I know:


GK-2A makes no use of pin 9, (its a "no connect" free pin)  whereas on the  GK-3 pin 9 is utilized:

==============

Reposted from the Yahoo MIDI Guitar Forum

Richard McClish wrote>
http://launch.groups.yahoo.com/group/midiguitar/

The GK-3 driver doesn't need the control voltages, it provides them.

As per Roland's 2004 preliminary GK-Compatible Guitar Design guidelines,
the DIN-13 pin 9 has the following spec:

__________________________________________________


GK-3  pin no. 9 assignment:
Name: "Sel"

Function:select signal
GK-3 Pin  9 Specifications:

0.521V(+/-5%) : GUITAR position of GK-3 compatible
1.042V(+/-5%) : MIX position of GK-3 compatible
1.563V(+/-5%) : GK (Synth)  position of GK-3 compatible

other conditions are prohibited
 
__________________________________________________


IMHO, the exclusion of function is a greater loss
than the function gained.

More study is needed to review the grounds for
compliance with this preliminary specification
in view of the global product line.

All RMC polyphonic preamps are GK-2/2A compatible and
have DIN-13 pin 9 going to an easily accessible solder pad
near the DIN-13 jack.

The RMC Fanout Box treats pin 9 like any other general
purpose I/O line.

All GK cables have 13 functional lines.
Inter-wire capacitance is about 30pF per foot.

Experimenters welcome...

Best regards,

RMC

...yahoo.com/group/midiguitar/message/23489

Thread: Re: DIN-13 Pin-9 ->Active PU?

Information courtesy of Richard McClish

Tuesday, February 27, 2007

============

Elantric wrote>
I understand the "new" pin 9  function exclusive to the GK-3 would possibly provide a path for future Roland 13 pin products to "read" the status of the three way "Guitar / Mix /Synth" switch - but so far this function seems to NOT be employed.
My theory is that someday Roland will offer the GK-3's 3-way switch as a possible User Control, and may provide a path to include this GK-3 switch as a User Assignable Control source for user assignable target parameters.  - but so far its not implemented in any other hardware.   

Reference for Roland GK-13 Pin Interfacing
http://ftp.terratec.de/AXON/HELP_FILES/AXON_13-pin_Specification_v1.0.pdf


====

Audio voltage measurements on a GK3.

GK3 TESTS. 0 volts dBm / 0.775dBm

Playing hard = 1.7V

Soloing moderate to hard = 640mV

Strumming lively = 480mV

Finger Picking Lively = 200mV

Moderate Plectrum Playing = 180mV

Light delicate playing = 50mV

All this is, I'd say +-3dB. It's also quite easy to increase the individual string outputs on a GK3 pickup with just 6 resistor changes. At the same time, it also improves the signal-noise- ratio.

« Last Edit: December 16, 2017, 03:11:35 PM by admsustainiac »

Offline Elantric

Re: Schematics
« Reply #2 on: January 24, 2008, 02:00:47 PM »
« Last Edit: January 30, 2008, 06:39:30 PM by sustainiac »

Offline mos6507

Re: Schematics
« Reply #3 on: January 25, 2008, 01:01:08 PM »
I'm assuming, though, that you can cut pin 9 with no ill effects?  Oddly enough if I change the VG-99 GK settings back and forth between GK2 and GK3 I don't really notice any difference in function.  I have a Switch Wild IV and can't really tell whether it has a GK2 or GK3 kit.  It seems like the VG-99 might try to auto-detect the pin 9 signal and fall back when appropriate.



« Last Edit: January 25, 2008, 01:04:12 PM by mos6507 »

Offline Elantric

Re: Schematics
« Reply #4 on: January 25, 2008, 01:49:43 PM »
Yes - when doing a custom rig, I would skip the voltage feedback "feature" of the GK-3.
I use an RMC Fan-out box, which lets me "break-out" Pin 9 lead and I can remap it to do more useful functions.



Like this post suggests:

http://www.vguitarforums.com/smf/index.php?topic=45.0

Offline Elantric

Re: Schematics
« Reply #5 on: April 30, 2008, 06:07:52 PM »
GK Internal Wiring Sheet
https://images.static-thomann.de/pics/atg/atgdata/document/installation/183640_gk_kit_gt3_install_g.pdf

Reference for Roland GK-13 Pin Interfacing
http://ftp.terratec.de/AXON/HELP_FILES/AXON_13-pin_Specification_v1.0.pdf

Roland Ready Strat
http://support.fender.com/service_diagrams/stratocaster/013-4660C_SISD.pdf



Suggest download the official Fender Roland Ready Strat service manual which lists all part numbers.
http://www.vguitarforums.com/smf/index.php?topic=73.0

http://www.vguitarforums.com/smf/index.php?action=dlattach;topic=73.0;attach=6977

Many of these parts ( including switches)  can be ordered from either Fender or Roland  - since the GC-1 uses the identical switch.

But Observe these switches are mounted on an internal plastic block which is glued to the back side of the Roland Ready / GC-1  Strat pickguard 

P/N# 0022602000 = White S1, S2 Switch cap
P/N# 0038462000 = Plastic Internal S1, S2 switch mounting block.

Call Fender Customer service in Arizona
http://www.fender.com/support/articles/contact-consumer-relations/
Fender Musical Instruments Corporation
Attn: Consumer Relations Dept.
17600 N. Perimeter Drive, Suite 100
Scottsdale, AZ 85255

Telephone: (480) 596-7195
Fax: (480) 367-5262
E-mail: consumerrelations@fender.com


Or Roland US CUSTOMER SUPPORT

To order parts, literature, or for repair issues, please contact Customer Support at (323) 890-3740. Customer Support is open Monday through Friday, 8:30am to 5:00pm Pacific Time.

Roland Corporation U.S.
5100 S. Eastern Ave.
Los Angeles, CA 90040-2938
(323) 890-3740.
 
« Last Edit: November 02, 2017, 12:50:00 PM by admsustainiac »

Offline Dog Rox

Re: Schematics
« Reply #6 on: June 08, 2013, 08:12:07 AM »
Ok this is an old post that i am replying to but i find it VERY helpfull for a specific part i need.  Thanx for posting the Parts Lists and Schematics and  all the other information!!  :)
« Last Edit: June 08, 2013, 08:18:37 AM by Dog Rox »

Offline Elantric

Re: Schematics
« Reply #7 on: December 29, 2013, 02:07:37 PM »
Alternate source for vintage Roland repair parts
http://www.vintageplanet.nl/pages/roland2.html


All Roland Ready Strats operate identically to the Roland /Fender GC-1 - (Click link for Owners Manual)

http://www.musicalstore2005.com/guida_e_manuali.php?products_id=26578

the only issue with a standard GK-KIT-GT3 installation, the mag PU is being  "loaded down" due to the input impedance of the GK-3 connection = dull sound for the mag PU's

That is one aspect where on the Fender Roland /ready / GC-1 Strat, Fender deviated from the official Roland GK-KIT-GT3 installation method, by adding that special 1/4" output jack with the normally closed switch that feeds the GK preamp board

« Last Edit: September 07, 2017, 08:33:36 AM by admsustainiac »

Offline Heymikey!

Re: Schematics
« Reply #8 on: November 11, 2014, 12:27:19 PM »
Hello Virtual Guitar folks! I tried searching and searching, but I can't find where to grab a mount that mounts the GK2 unit itself (not the pickup). I need to mount the unit to the strap plug at the bottom of a Strat.

Checked on eBay as well - nothing.

Thanks in advance for any input.
« Last Edit: November 11, 2014, 12:59:48 PM by Elantric »

Offline Elantric

Re: Schematics
« Reply #9 on: November 11, 2014, 12:39:43 PM »
Review the service manuals
http://www.vguitarforums.com/smf/index.php?topic=73.0
http://www.vguitarforums.com/smf/index.php?action=dlattach;topic=73.0;attach=6628



Sounds like you need

"Holder A" = Roland P/N G2147812

"Holder B" = Roland P/N G2147813


and order the part you need from Roland Customer Service in LA
Roland Corporation U.S.
5100 S. Eastern Ave.
Los Angeles, CA 90040-2938

(323) 890-3740.
« Last Edit: November 11, 2014, 12:44:38 PM by Elantric »

Offline gibvictory

Re: Schematics
« Reply #10 on: December 03, 2014, 04:32:38 PM »
I found the link here for the metal one. Does anyone have the link for the Roland one? I'm having my Roland Strat repaired so I can sell it and a direct replacement is all that is necessary. Not very fond of that particular guitar. I want to buy a much nicer strat and install a GK in that.

Thanks,
Russ
« Last Edit: December 03, 2014, 04:33:29 PM by Elantric »

Offline Elantric

Re: Schematics
« Reply #11 on: December 03, 2014, 04:34:39 PM »
Roland Ready Strat
http://support.fender.com/service_diagrams/stratocaster/013-4660C_SISD.pdf



Suggest download the official Fender Roland Ready Strat service manual which lists all part numbers.
http://www.vguitarforums.com/smf/index.php?topic=73.0

http://www.vguitarforums.com/smf/index.php?action=dlattach;topic=73.0;attach=6977

Many of these parts  can be ordered from either Fender or Roland  - since the GC-1 uses the identical 13pin Jack


P/N# 0048541000  Assy.-Output Jack 13 Pin, Roland

Call Fender Customer service in Arizona
http://www.fender.com/support/articles/contact-consumer-relations/
Fender Musical Instruments Corporation
Attn: Consumer Relations Dept.
17600 N. Perimeter Drive, Suite 100
Scottsdale, AZ 85255

Telephone: (480) 596-7195
Fax: (480) 367-5262
E-mail: consumerrelations@fender.com


Or Roland US CUSTOMER SUPPORT

To order parts, literature, or for repair issues, please contact Customer Support at (323) 890-3740. Customer Support is open Monday through Friday, 8:30am to 5:00pm Pacific Time.

Roland Corporation U.S.
5100 S. Eastern Ave.
Los Angeles, CA 90040-2938
(323) 890-3740.
 
« Last Edit: December 03, 2014, 04:36:38 PM by Elantric »

Offline gibvictory

Re: Schematics
« Reply #12 on: December 04, 2014, 05:15:32 PM »
First of all I was quoted $90.00 from Fender, ouch! Of course that was with the circuit board. Let me describe my problem. I'm getting no audio via midi. However, I can see each string in the tuners of both my GR55 and GR 33. I picked up the strat at a good price and had a friend make and install new pickups. The audio via midi stopped working and we managed to fool around with the wires testing and reseating and it worked but only for a short while. Any ideas about what the problem might really be? My same friend thinks I should let him try some things before I commit to the $90.00. He suggests we find a new female13 pin replacement jack and although tedious, he believes he can remove that from the PCB board and repair everything. Is that ill advised? Has anyone done anything like that. Can an alternative be suggested? Lastly can anyone link me to a source. I'm finding them when I search but I'm not at all confident they will work. I found the link to a metal one here with the two wings but I would like to find one that will fit right in the strat without modification.

Thanks,
Russ
« Last Edit: December 04, 2014, 05:54:15 PM by Elantric »

Offline Elantric

Re: Schematics
« Reply #13 on: December 04, 2014, 05:29:32 PM »
Quote
I'm getting no audio via midi. However, I can see each string in the tuners of both my GR55 and GR 33.
Not understanding you at all

FWIW - There is ZERO MIDI occurring in the 13 pin cable  - the actual circuit path is the Guitar > Roland Magnetic "Hex" PU > internal 6 channel "one per string" analog preamp + a buffer for the normal pickups to drive down the 13 pin cable  - then into the receiving 13 pin device with "GK IN" 13pin DIN jack

Like this:

GK-2A


GK-3

While older Roland VG/GR units supported a functional Three way "Guitar/Mix/Synth" Selector switch on your guitar- the Latest Roland GK 13 gear built since 2007 (VG-99/GR-55) feature factory presets where Roland Intentionally disables the normal guitar pickup signal on the guitar ( Yes they intentionally create a hurdle for you to use your normal pickups "by design"!)  You must create User presets that "re-enable" the Three way "Guitar/Mix/Synth" Selector switch on your guitar!

This is why we have these threads:

GR-55 FAQ - Top Things To Know
http://www.vguitarforums.com/smf/index.php?topic=4006.0


* How to enable "Normal Guitar Pickups" and make the GK-3 Guitar/Mix/Synth three-way switch work with the GR-55:
http://www.vguitarforums.com/smf/index.php?topic=3402.0



Quote
I picked up the strat at a good price and had a friend make and install new pickups.

Not to nit pick - but 99% of Luthiers and electric guitar gurus typically know zilch about Roland Ready Strats  - and often its an internal  loose wire that was damaged when the "guru" swapped out the normal pickups
http://www.randyciak.com/guitar/index_roland_duck.htm


The  Roland Ready Strat Service manual is here:

http://support.fender.com/service_diagrams/stratocaster/013-4660C_SISD.pdf


Highly recommend seeking assistance from your local  Roland Service Center

http://www.rolandus.com/support/service_centers/

 for repair issues, please contact Customer Support at (323) 890-3740. Customer Support is open Monday through Friday, 8:30am to 5:00pm Pacific Time.

Roland Corporation U.S.
5100 S. Eastern Ave.
Los Angeles, CA 90040-2938
(323) 890-3740.
« Last Edit: August 23, 2017, 11:39:19 AM by Elantric »

Offline gibvictory

Re: Schematics
« Reply #14 on: December 04, 2014, 07:19:20 PM »
Let me clarify a bit.  My path is Brian Moore/Roland Strat via 13 pin to synth. Left out for synth sounds and guitar out to Axe Fx separate inputs. I'm aware of the guitar/mix/synth issue with the Gr55 and am using user presets and all is well thanks to VGuitar Forum. Certainly something did happen when we replaced the pickups. So here I am. Both my GR55 and 33 tuner see all six strings. The guitar out signal is passing through the synth to the Axe. The LED input indicator on the Axe registers nothing from the L out of both synths when using the strat. While we were trying to check all the internal connections one side of the female connector, where one of the screws went through, cracked. Although fairly secure I want to replace it. My friend at this point thinks that's where the problem resides.

I will send him the link to the manual. Just looking for an arrow to point me towards the correct 13 pin connector.

Offline Elantric

Re: Schematics
« Reply #15 on: December 04, 2014, 08:13:21 PM »
Also consider  this

If Fender wants $90 for just the 13pin Output jack  - and Roland Service Centers typically charge $75 /hour, just get the entire Roland Internal Kit with Hex PU delivered for $135 and work slowly with the installation instructions, and prior posts in this thread - all info a competent Electronics Technician / Ham Radio Operator  / Local Robotics club needs to repair your guitar is right here in this thread 

Roland Internal GK-Kit-GT3 (75 British pounds) or $135.00 USD including three day delivery to USA via DHL 


http://www.vguitarforums.com/smf/index.php?topic=12060.0
http://www.andertons.co.uk/electric-guitar-pickups/pid12319/cid705/roland-gk3-internal-pickup-kit.asp


« Last Edit: December 04, 2014, 08:24:21 PM by Elantric »

Offline gibvictory

Re: Schematics
« Reply #16 on: December 07, 2014, 05:58:22 PM »
Thank you, will be working on it this week.

Offline Elantric

Re: Schematics
« Reply #17 on: January 28, 2015, 12:22:23 PM »
Boss EV-5/FV-60 Service Manual

Offline Elantric

Re: Schematics
« Reply #18 on: March 01, 2015, 05:42:31 PM »
Roland GKP-4 -  schematic  -
there's not much too it
http://www.vguitarforums.com/smf/index.php?topic=5816.msg39850#msg39850


Its important to utilize Steering Diodes on Pins 12 & 13 on each 13pin DIN jack,  to prevent cross-connecting the +7V and -7V Power Rails on device connected.

and I would add Ground Lift option removable links to decouple the DIN Shells on the B,C,D 13 pin jacks - for lower noise.   




« Last Edit: August 23, 2017, 11:37:32 AM by Elantric »

Offline obiwanjacobi

  • Active Member
  • **
  • Posts: 18
  • Total likes: 0
  • Rating: 1
  • More controls does not mean more control.
Re: GK Schematics
« Reply #19 on: June 22, 2015, 02:40:02 AM »
Not sure the schematics for the GK-Kit_GT3 are 100% correct. They may work but on the PCB I see 8 packages that looks like (SMD) transistors that are not on the schematic...

[2c]
Grtx, Marc

Online gumtown

Re: GK Schematics
« Reply #20 on: June 22, 2015, 03:52:28 AM »
Not sure the schematics for the GK-Kit_GT3 are 100% correct. They may work but on the PCB I see 8 packages that looks like (SMD) transistors that are not on the schematic...

[2c]
DA1 to DA8 are diode arrays which prevents the output exceeding the supply rails and damaging the op-amp chips from transients and electrostatic discharge.
Like these
http://www.littelfuse.com/products/tvs-diode-arrays.aspx

« Last Edit: August 23, 2017, 11:41:57 AM by Elantric »
Free "GR-55 FloorBoard" editor software from http://sourceforge.net/projects/grfloorboard/

Offline raccio14

Re: GK Schematics
« Reply #21 on: April 14, 2016, 07:17:40 PM »
What is the power supply specification for the GK-3?

Online admsustainiac

Re: GK Schematics
« Reply #22 on: April 14, 2016, 07:49:23 PM »
The Roland/Boss GK Processor's GK 13 pin interface supplies:

Pin#12 = +7VDC @ 100mA

Pin#13 = -7VDC @ 100mA

Large round DIN Plug Shell = Ground Reference
« Last Edit: April 14, 2016, 07:52:16 PM by admsustainiac »

Offline bea

Re: GK Schematics
« Reply #23 on: July 06, 2016, 01:59:40 PM »
And how much of that do the Opamps use?

Offline Elantric

Re: GK Schematics
« Reply #24 on: July 06, 2016, 02:25:38 PM »
The "big deal" regarding the available max 100mA DC current on Pin #12 (+7VDC) & Pin #13 (-7VDC) is:

*  These voltages must power any attached GK 13 pin guitar and its onboard preamp. often this includes a Piezo Mono Preamp (RMC , Graphtech)

*  These voltages must power any attached GK 13 Accessory ( Roland US-20 A/B/Y selector, Roland GKP-4 Parallel Router, etc)




 
Quote
And how much of that do the Opamps use?

Really depends on the specific attached Gk Hex PU type (GK-2A, GK-3, Yamaha G1D, GraphTech Ghost with Mono Piezo preamp, RMC PolyDrive1,RMC PolyDrive2, RMC PolyDrive IV, etc.

To get a ballpark number, I review the OpAmp datasheet, and review the max nominal DC current draw (ICC), and multiply by the number of OpAmps   


Here is a GK-2A


It employs NEC uPC4570 op amp

Here is the datasheet

http://pdf1.alldatasheet.com/datasheet-pdf/view/6770/NEC/UPC4570.html

and Supply Current (ICC)  = 8 mA typical worst case for each OpAmp

There are five opamps  = 40mA Supply Current


It becomes a problem when your attached 13 pin gear exceeds the GK supply current sourced from the GK Processor (VG-99/GR-55/GP-10, etc), which may occur if you employ a third party GK Guitar Selector that supports connecting 3 or 4 GK guitars at same time.

* Four Gk Guitars at 40mA each = possible 160mA
   GK Guitar selector accessory  = typical 50mA  = 210mA total current draw
« Last Edit: July 06, 2016, 02:46:09 PM by Elantric »

 

Blog