GK-13 Pin Cable FAQ

Started by Elantric, November 19, 2008, 11:44:28 AM

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Elantric

Warning  - Wrong GK 13 Cable may damage your GR/GP/VG Processor

Be sure you purchased a genuine Roland GK compatible 13 pin DIN cable

Get an ohm meter and verify all 13 pins are wired "1:1" at both sides of the cable, and no pins are shorted together on the same end

Know that most 13 PIN DIN cables are designed for Kenwood / Clarion Car Stereo CD changers  - and those are NOT compatible with Roland Gk Guitar Synths
https://www.vguitarforums.com/smf/index.php?topic=3132.msg28280#msg28280



if you examine the details of the GK-3, it becomes apparent MIDI data messages have never existed in ANY 13 pin interface from Roland or Any other manufacturer at anytime.
Essentially the GK-3 is a multichannel analog Buffer/Line driver !



In 2018  - the best GK 13 cables are

PRIMOVA - GK-13 - Codesmart's Excellent GK 13 pin Cables
https://www.vguitarforums.com/smf/index.php?topic=13234.0


D13 Gittler Synth/MIDI Cable 13-pin Din Roland Ready
https://www.amazon.com/gp/product/B01CPKKVSI/ref=s9_acsd_hps_bw_c_x_2_w


Best-Tronics MIDI13-XX
https://btpa.com/MIDI13-XX.html?category_id=170




Clean and Maintain your GK-13 Cable
https://www.vguitarforums.com/smf/index.php?topic=3132.0


These tips below prevent GK 13 cable noise issues manifesting at an important gig

* Order quality GK-13 cables

   Gittler GK-13 Superior Cable (WITH a right angle connector)
    https://www.vguitarforums.com/smf/index.php?topic=11243.0

    or

   BTPA GK-13 cable
   http://btpa.com/13-Pin-Midi/

   or

   Primovasound GK-13 cable ( send a PM to member Codesmart) 
   https://www.vguitarforums.com/smf/index.php?topic=13234.0

* Use 13-PIN PLUG & SOCKET DUST COVERS
   https://www.vguitarforums.com/smf/index.php?topic=18487.msg136189#msg136189

   

   

* Extend the life of your new GK-13 cable by winding them properly to avoid internal kinks  that can damage internal wires middle of the cable
   https://www.vguitarforums.com/smf/index.php?topic=17715.msg126215#msg126215
   

* Store GK-13 Cables in a separate hard case to prevent them getting crushed during transit

   

* Carry a small can of Caig DeOxit

   


* Perform the GK 13 pin Cable Maintenance Tips.
https://www.vguitarforums.com/smf/index.php?topic=3132.0



The Ferrite core is typically inside the VG-99 shipping box, it gets applied to the Gk13 cable near the VG-99 , to aid in preventing RF EMI radiation generated by the VG-99's CPU from interrupting local radio and TV reception.  Its due to more stringent FCC/ CE  RF emission standards for consumer gear.

Roland has a Ferrite core PDF doc with instructions on how to use it. (see attached file)

There is a basic underlying control element at work with all Gk 13 pin Processors which is important to understand

Anytime you change from Guitar Mode to Synth mode, its important to understand the signals do NOT get switched

Instead,  the Roland / Boss design employs this global axiom -   mute the unwanted signal Path

This is done anytime you move the Three way "Guitar/Mix/Synth" switch on the GK-3 , or move the Gk VOL pot on the GK-3.

These user controls are actually altering important DC Control Voltages on the target GK Processor ( VG-99. GR-55. GP-10), whose DSP's are performing "VCA"( Voltage Controlled Amplifier) adjustable gain blocks to control the volume or mute each portion of the Guitar and Synth signals on GR-55

So a wonky GK 13 pin cable , or wonky Three way switch on GK-3 , or wonky Synth volume or ( on Fender GC-1/Roland Ready Strat) a wonky 1/4" switching output jack all could conspire to mute your volume at the gig.   


--

Axon Docs (see attached)

AXON 13-pin Pickup Connector Specification
1. Pinning 13-pin Connector

1 Analog signal e-string (highest frequency)
2 Analog signal B-string
3 Analog signal G-string
4 Analog signal D-string
5 Analog signal A-string
6 Analog signal E-string (lowest Frequency)
7 Analog signal guitar pickup ("normal" magnetic pickup)
8 DC-level for synthesizer volume (wavetable volume)
9 Not connected
10 Down switch signal (switch to GND)
11 Up switch signal (switch to GND)
12 +7 V DC power supply for OP's
13 -7 V DC power supply for OP's
(14) Shield serves as GND

2. Analog string signals
Source impedance pickup side should be around 100 Ω
• Input impedance of AXON ADC is 20 KΩ
• Maximum voltage swing is +-2.5Vpp

3. Normal guitar pickup signal
• Source impedance Pickup side should be around 100 Ω
• AXON directly connects this signal to his TRS guitar out jack without any
additional amplification

4. DC-Level for synthesizer volume
• Source impedance pickup side should be around 100 Ω
• Buffered DC-level from 0-5 V to control synthesizer volume

5. UP/DOWN switch signals
• Pickup UP/Down switches connect these signals via R-C-R T-Network
(470 Ω – 10 nF – 470 Ω) to GND

6. +-7V power supplies
• Maximum supply current: 100 mA

7. Pin 14 (shield) of 13pin jack MUST be connected to GND
     


Meltdown

There wasn't one in my sealed box, and it came directly from roland Benelux distributor without any musicshop interference.
Weird.
Visit my website!
http://www.tachyonmusic.com

washburn100

There wasn't one in my sealed box as well. Interesting, the manual that came with my VG-99 mentions using the magnet, that's why I posted here. I downloaded the on-line manual and that page is not there. Anyone know why Roland took this out of the manual and the box?

Elantric

#3
Probably because the VG-99 does not actually need this ferrite core. There are many classifications in the maze of FCC emission standards. If Roland tells the FCC to classify the  VG-99 as Commercial Audio Equipment rather than Consumer Electronic gear - then the RF emission standards are less stringent, and Roland saves money by not having to include a ferrite core.
Also effective Jan. 2009 the analog TV broadcast spectrum in the USA changes, this may be a factor, its no secret that every manufacture is seeking all methods to increase profit by trimming  all surplus costs from every product.

In the USA if you desire a ferrite core - www.jameco.com has them.

Its only needed if you are disturbing  local TV reception.

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=421681

spankygtr

#4
I responded to an earlier post about popping noise when using cosm models.
However, since that is an old post, I thought it would be better to start a new thread about the topic, just so I could learn whether this a problem for other users.
I often get bad noise when I move my cable (particularly with high gain COSM based patches, like "Legato Solo").  If I move around on stage too much, the noise gets pretty bad, and the built in   noise suppressors are not eliminating it out without excessively high settings (which adversely affects sustain and makes delicate playing impossible). (This is not an issue if I'm using pcm based patches, however, I'll sometimes get random notes out of nowhere when I move the cable too much).
I thought I had a defective unit, and sent it in for repair. A Roland tech told me the noise is normal, as he was able to recreate it with a new unit.
My question is: how many users out there have experienced this problem?

Elantric

#5
Clean your cable

This video explains all the above problems.


Solution is here:
https://www.vguitarforums.com/smf/index.php?topic=3132.0


Quote
Anyway, thanks and what is the best source for a new Gk 13 pin DIN cable .

Gittler GK13 Superior Cable (WITH a right angle connector)
https://www.vguitarforums.com/smf/index.php?topic=11243.0

or

BTPA 13 pin cable
http://btpa.com/13-Pin-Midi/

spankygtr

I already used DeOxit on TWO DIFFERENT cables, and get the same noise with TWO DIFFERENT guitars. (And remember, a Roland tech reproduced the problem with a DIFFERENT GR-55 (his name is Joe).

drjoness2001

My experience is that the whole DeOxit thing is way over played.

I do not think it helps at all. More likely, the issue seems better because you are re-seating the cable.

I work with a lot of 25-year old vintage synth gear, and most of it has excellent connectors doing quite well, without the need of DeOxit.

If guitar players are using their gear in an environment where you are getting enough build-up on your 13-pin connectors to warrant spraying you connectors with DeOxit all the time, then they rest of your gear should be suffering to greater extremes. How often are you spraying DeOxit on your 1/4" guitar cables?

For me the flaw remains the 13-pin connector. This was originally a video monitor cable, and it's really not well-suited to guitars. I've got new cables, old cables, new synths, old synths, and they all make noise when I giggle that 13-pin connector.

If you have high-gain patches, then it can sound really bad.

The best solution is to stabilize the cable and live with it.

gumtown

I haven't noticed the problem, but then i don't use hi-gain patches for Bass.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

Naphthol

A cheap noise gate pedal at the end of a chain might solve some issues.  Also, it might not.   :-\

I've had cable connection noises and sound artifacts with many devices i've used in a variety of states of wear.  it's just a reality of working with audio equipment i've found.  for years, my bass guitar made some really odd and random noises when it's connection area was nudged - sat on my guitar rack for a few months - now it doesn't make noises any more.

my bass circuitry is haunted.  :o

Guitarbot

I actually use the cables from ebay that everybody says are cheap & recommends not using.  They work fine in my home studio because I am not bouncing around.  As far a live, I have better cables.  Nomatter what, I think the 13 pin cable is the weakest link in the system.

Paresh

I get that noise with Roland cables right out of the box. Annoying...
paresh

aliensporebomb

Speaking of haunted equipment, check this site out and download the MP3 involved.  Brrrr.  I get shivers:
http://www.gunslingbirds.com/ondines-curse/

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

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

ganderpe

Helo,
I've got two cables on my vg-99, both of them produce this nois, but one much more then the other.
I think the problem is, that additionaly to the ac sound signal, there is also a dc part from the +-7.5 V suply. And due to this dc part the movements of the connector produce the noise.

Peter
Fender Stratocaster Eric Johnson, GK-internal,  VG-99 fw1.04, FC-300

mariogag

Quote from:  ganderpe on August 02, 2011, 06:18:50 AM
Helo,
I've got two cables on my vg-99, both of them produce this nois, but one much more then the other.
I think the problem is, that additionaly to the ac sound signal, there is also a dc part from the +-7.5 V suply. And due to this dc part the movements of the connector produce the noise.

Peter

I have a bunch of hardware (all Roland) and and 3 equipped (1 GK, 1 with piezo PU brand X, 1 with with piezo PU Brand Y)
and I have come to the conclusion that I will have problems if I used 13-pins cables or GK connectors that are
not locking.

My only setup that will cause me problems when I "tap"/move the cable near the guitar is the one where I use
my piezo equipped guitar that has a non-locking cheapo GK connector.

I have used this instrumment with 3 different GK 13-pins cables (2 new, 1 old) and nothing will do; the problem
is with the poor quality of the 13-pins connector used.

The only solution I have found when using this guitar is to stand still as much as possible, particularly when
I am using high gain patches.

M


5strings

Quote from:  drjoness2001 on July 31, 2011, 10:35:15 PM
My experience is that the whole DeOxit thing is way over played.

I do not think it helps at all. More likely, the issue seems better because you are re-seating the cable.

I work with a lot of 25-year old vintage synth gear, and most of it has excellent connectors doing quite well, without the need of DeOxit.

If guitar players are using their gear in an environment where you are getting enough build-up on your 13-pin connectors to warrant spraying you connectors with DeOxit all the time, then they rest of your gear should be suffering to greater extremes. How often are you spraying DeOxit on your 1/4" guitar cables?

For me the flaw remains the 13-pin connector. This was originally a video monitor cable, and it's really not well-suited to guitars. I've got new cables, old cables, new synths, old synths, and they all make noise when I giggle that 13-pin connector.

If you have high-gain patches, then it can sound really bad.

The best solution is to stabilize the cable and live with it.

I'm almost certain most noise issues arise with poor fit: a less-than-positive connection between the 13-pin and its receptacle. I've often jarred the cable on my knee while playing while seated. I always felt that the 13-pin cable works better with some effective strain relief. Does anyone have an effective strain-relief solution for an iguitar/13-pin connection? I often try looping the cable through the guitar strap before connecting, but that usually tangles.

Does a

Brent Flash

Quote from:  5strings on August 15, 2011, 10:06:49 PM
I'm almost certain most noise issues arise with poor fit: a less-than-positive connection between the 13-pin and its receptacle. I've often jarred the cable on my knee while playing while seated. I always felt that the 13-pin cable works better with some effective strain relief. Does anyone have an effective strain-relief solution for an iguitar/13-pin connection? I often try looping the cable through the guitar strap before connecting, but that usually tangles.

Does a
I have never had any problem with my 13 pin connection, as long as I keep the contacts clean. I had bought a spare a couple of years ago when I got the VG and have never had to use it. Just saying.

FreeTime

I've worked in industrial processing where even trace amounts of ambient SO2 would cause the computers to fail in a very short time, .
I'm wondering if those people that are having problems don't live in very urban centers where their gear is exposed to a more corrosive atmosphere, causing galvanic reactions.
A gold plated connector (both male and female) would fix that problem.

mariogag

Quote from:  FreeTime on August 16, 2011, 05:41:57 AM
I've worked in industrial processing where even trace amounts of ambient SO2 would cause the computers to fail in a very short time, .
I'm wondering if those people that are having problems don't live in very urban centers where their gear is exposed to a more corrosive atmosphere, causing galvanic reactions.
A gold plated connector (both male and female) would fix that problem.

once again,

Cheap non-locking 13-pin female connector are a serious problem.

Same high gain patch, same 13-pin old cable, sme basement....my RMC (it uses a locking connector) equipped Multiac Jazz  is silent even if I knock the cable hard; however my Ghost (it uses a non-locking connector) equipped Freeway-SA becomes a noise/crackle by simply moving around.

The original ghosts board was removed 12 months after the guitar was bought and the same annoying
behavior came back a week or so after getting my guitar back.

M

ganderpe

...any light  mechanical movement of the connector pins will result at least in a small change of contact resistance.
The sound of the guitar is the ac voltage between the ground pin and the signal pin (times 6 with hex pickups).
The supply of the hex pickup electronic is +7.5V, -7.5V and 0V (ground).
If the current flow of the +7.5V pin is, let's say 20mA more then on the -7.5V pin, this 20mA dc current flows throu the ground pin and the whole cable and produces (due to the connection resistance) a constant dc voltage on the sound signal path.
This has no effect on the sound, as long as the connection resistance is constant, because the input capacitor in the vg-99 is filtering out this dc part. But as soon as you move the connector, the resistance will slightly change and this change produces in combination with the 20ma dc current an ac signal that we hear as noise.

The older people of you (as i am :-) ) may remember the radios 30 or 40 years ago, when the old capacitor near the volume potmeter had a leak current, the result was also a noise, when changing the sound volume.

Peter
Fender Stratocaster Eric Johnson, GK-internal,  VG-99 fw1.04, FC-300

Elantric

#20
Good solid info above Ganderpe!
This video explains all the above problems.





Most electronic folks know the most important signal in any electronics gear is the Ground Connection.
How I wish back when Roland changed the Roland Guitar Synth Interface cable specification  from the 1980-1987 24 pin type interface (with 4 GND pins!)  to the 1988 era circular DIN 13 pin interface we all use today , that they provided an actual GND PIN!

Review the pin assignments on the far right in this pic.
(Roland GK-3 Schematic)

Observe none of the 13 pins are used for Ground!.
Sadly, the only Ground Connection Roland provided in the GK13 interface is the large round chrome circular shell we all see on the male plugs surrounding the 13 pins at each ends of our Roland GK cables

Some may think "So whats the problem?"

The problem  for most is the typical miniscule mating ground contact "finger" on the Female 13 pin jack.
 
Many third party "GK13 compatible" gear vendors, (Graphtech Ghost) employ 13 pin Female jacks that do not provide a robust electrical Ground connection to the Male plug's Ground Shell.
The "achilles heel" weakest link is the tiny mating electrical contact finger for the large round Shell  'Ground" connection on the female 13 pin jacks on your guitar, GK-3 or  VG-99, GR-55. If this important electrical connection is flaky - you will have problems just as you are currently experiencing ! (see yellow circle below)



The slightest move of the Male plug makes lots of rice crispy noises: "snap, crackle, pop!. or worse! (total signal drop out)

Links to sites providing more details about the Roland Synth cable is here:
http://johnp.net/projects/guitar-synth/roland-pinouts.html

http://www.marksmart.net/gearhack/gr300/analogmods/395report/Report.html

Read:
Roland GK 13 pin Cable Maintenance Tips.
https://www.vguitarforums.com/smf/index.php?topic=3132.0

Eight_Stringer

#21
Not sure if this has been covered previous,  did not see anything related in a quick scan of this site.  Bought in from the USA a VG-99 and GK3 job lot.  All seemed ok at first then the 13 pin cable assembly became noisy,  only when the cable was moved at the VG99 end, about 2-3 feet of the cable actually.  Ordered in some DIN13 pin pcb sockets to help diagnose this problem, ie easy connection for the multimeter as i thought it was a broken/intermittent wire fault.  Alas no,  all wires were intact? Long story short,  days past we had problems with multimeter lead probes causing erratic reading on the connected multimeter ie ohms test probes shorted.

   We discovered that stretching the wires along the wire axis,  the erratic readings disappeared.   Nothing to loose,  VG99 in pickup test mode, i could see this "noise" on the display readout,  took about 5 minutes of careful stretching and the mechanical related noise became less and less, until it was as good as my reference cable ( have 3 13pin cable assemblies here ).  Actually nothing wrong with the DIN13  cable other than this anomaly that i have seen a few times in the last 40 years. See what happens over time. Best guess is galvanic voltages being produced on the stranded cable, pulling the cable removes any loose interactions between the twisted wires for each individual wire. Hope i make sense,  it may be something completely different than my best guess.  Regards.

Elantric

Great investigative work and thanks for posting!

The latest batch of Roland 13 pin cables are a true battle for the user.

Between the loose internal wire strands and the fine invisible film of protective coating the vendor puts on the metal contacts at each end, and the ONE ground connection on the circular shell, its a flawed design.

We have a thread on 13 pin cable connection cleaning here:
https://www.vguitarforums.com/smf/index.php?topic=3132.0

fokof

Got a GK cable from Carvin:
http://www.carvinguitars.com/products/single.php?product=C20P13&cid=45



It is better quality than Roland's offerings and cheaper , the plug is slightly smaller and a bit larger.
Can't say in the long term but after a month , I only use that one.


Funny how Carvin sells them as "MIDI" cables:
".....and other MIDI applications "

::)

Brent Flash