HOW TO MAKE A GK Y-CABLE

Started by PD FX, November 10, 2012, 01:15:03 PM

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PD FX

Quote from: tekrytor on November 10, 2012, 08:51:19 AM
I want to know how, more info please Guitarpolson! ;D

Here's how I did it, and, yes, I know its very crude ")

HOW TO MAKE A GK Y-CABLE INTUITIVELY...
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IMPORTANT: this is for more experienced hackers who dont mind cutting up cables!! No warranty, just works for me!!
Presuming you have 2 GK cables, dismantle one of them for about 8-10 cm, so that the colored leads can be touched. Do not strip any cable!
Now connect a GR55 or  VG99. Choose in "system" a guitar nr you dont use anyway, put all the string gains on max.
Now you can see and hear which lead is which string, just by touching.. As long as no guitar is connected, the wires are extremely sensitiv to hum, and your finger will induce this hum. Figure out which colour is which stringnr, write them down on a piece of paper.
These 6 signals and a ground level signal, for which you can use the mantle of the cable, can be used as "slave signal"
Use a second GK cable, determine the strings there (probably same colors). Write the also down on formentioned paper, behind the data from cable 1.
Now you can strip and solder the right wires together. Use shrinkwrap to cover it up.
One more thing: if the complete system with 2 GK devices hums too much, try "groundlift". This means you just disconnect the ground signal for the slave device. The slave device probably allready is grounded by the mixer, in which case an extra groundline would lead to hum.  A groundlift switch would be sweet I guess..
If you have 3 GK cables you can make 2 Y-cables out of them, so that there is a complete spare cable, just in case..

Elantric


PD FX

haha Elantric,
now that is the "technical way"!
I didnt feel like open the jacks, to see the colors, the prefab jacks are not that easy to open.
Thats why I used the intuitive methode.
But hey: I didnt know this forum with all it's infos, at the time I did this... ')

MarkFrancombe

I'm wondering about this: I notice that the switch connections have not been made to the second unit (in this case a GR33)

I have just gotten a GR33, after owning an old GR30. The 30 still works, and Id like to run them together, and simply use the GR30 as extra voices for the GR33.

My cunning plan was to plug the output of the 30 into the RETURN of the 33, adn then the OUT from the 33 into the desk.

Here my question, IF I wire up the switches too, will the guitar switches and knob control both units (this is what I want, somply make patches that use both devices, but afterwards forget them and treat them as one device, change a patch on on, and it changes on both.

PD FX

Hi Mark,
See attachment (knob circuitry GR30): it seems perfectly possible, the GR33 will have the same circuitry there.
Note that the impedance to VCC will be twice as low (23k5 instead of 47k on R49),
So the volumeknob will be less linear, but trying wont hurt I guess..

Here's the alternative:
You can use a midi cable to get the gr30 to play the same notes as your GR33 has detected. The volumeknob will be sent as CC #7, so you GR30 will have synchronous volume.
Secondly, the exp pedal will sent a CC as well, and your GR30 will behave like its own pedal is pressed ( but it can define its own action)

greetings,
GP




Quote from: MarkFrancombe on September 12, 2013, 05:15:56 AM
I'm wondering about this: I notice that the switch connections have not been made to the second unit (in this case a GR33)

I have just gotten a GR33, after owning an old GR30. The 30 still works, and Id like to run them together, and simply use the GR30 as extra voices for the GR33.

My cunning plan was to plug the output of the 30 into the RETURN of the 33, adn then the OUT from the 33 into the desk.

Here my question, IF I wire up the switches too, will the guitar switches and knob control both units (this is what I want, somply make patches that use both devices, but afterwards forget them and treat them as one device, change a patch on on, and it changes on both.

Elantric

#5
Quoteit seems perfectly possible, the GR33 will have the same circuitry there.

Without the GR33 Service Manual, its a gamble.

https://www.vguitarforums.com/smf/index.php?action=dlattach;topic=73.0;attach=7048

Refer to the above link .
If it were me I would insert a separate pair of "steering diodes in series with S1 & S2 GPIO switching signals feeding GK pins 10, 11 on each GK Out Jack. (i.e. Four 1N914 type switching diodes.)

If you omit these diodes you risk damaging both connected 13 pin processors.

MarkFrancombe

Quote from: Guitarpolson on September 12, 2013, 06:00:46 AM
Hi Mark,
Here's the alternative:
You can use a midi cable to get the gr30 to play the same notes as your GR33 has detected. The volumeknob will be sent as CC #7, so you GR30 will have synchronous volume.
Secondly, the exp pedal will sent a CC as well, and your GR30 will behave like its own pedal is pressed ( but it can define its own action)
GP

This seems like the way to go, I didn't quite get what you meant about the pedal, but I guess Ill find out:

One question you might know off the top of your head tho.
IF the GR30 is receiving note info from the GR33, will the GR30 Arpeggiator work as normal? or will it play the the arpeggiator pattern from the GR33??? Or none, cos maybe it only receives the raw midi data from the strings.

What I WANT, is that one chord will trigger both arpeggiators, with their differences in timing info.
(I haven't got into the 33 yet, but AFAIK, you cant program the arp pattern... very odd, its my fave feature on the 30, and why I don't just want to upgrade to the 33.



Elantric

#7
Our tests show GR-30 triggers Guitar to MIDI faster than GR33 or GR55.

No need for custom Y cable really.

I would run 13 pin guitar to GR30 and use MIDI cable from GR30 MIDI Out to GR33 MIDI In.
Use an EV5 expression pedal with GR30 for GR30 volume and use GR33 onboard expression pedal for GR33 volume and run both into a small mixer.

The above method also allows full use of GR30's Arpeggiator to drive both synth engines too.

Jim Williams

I thought it might be useful to make a cable that had a 1/4 inch cable out of it for a better normal pickup out to a guitar effects board.
Skype: (upon Request)

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

MarkFrancombe

Quote from: Elantric on September 13, 2013, 07:20:46 AM
Our tests show GR-30 triggers Guitar to MIDI faster than GR33 or GR55.
No need for custom Y cable really.
I would run 13 pin guitar to GR30 and use MIDI cable from GR30 MIDI Out to GR33 MIDI In.
Use an EV5 expression pedal with GR30 for GR30 volume and use GR33 onboard expression pedal for GR33 volume and run both into a small mixer.
The above method also allows full use of GR30's Arpeggiator to drive both synth engines too.

After quite a delay, (gigs, wives, real-life...) Im back to trying this:

Firstly, I have plugged it up as started,
(GK cable into GR30, GR30 plugged into a GR33 with a midi cable)
I've set both to the same midi channel, I can see that the GK s1 and 2 are changing patches on both. However sound is only coming from the GR30. Does the GR33 need to be in local control off mode?

You state in your final line above
Quote from: Elantric on September 13, 2013, 07:20:46 AM
The above method also allows full use of GR30's Arpeggiator to drive both synth engines too.

But thats NOT what I want really, I want the GR30 to use its GRET arpeggiator and the GR33 its so so one. Having the same arp pattern applied to all 4 voices would be BIG, but, its gonna be cooler if they are different.

Is this achievable anyway by sending the midi generated on the 30 and sending it to the 33? Or are we back to splittin cables again?

Mark



Elantric

#10
Read GR30 Owners Manual. And GR33 Owners Manual.

On GR30 you must enable MIDI Note Transmission

On GR33 you must enable External  MIDI Note Reception.

MarkFrancombe

heh heh.. OK OK.. I admit I was trying to skip all that leg work, and trial and error... Damn... busted... Could take years for me to figure out.. but ok.. Ill dive in...

Jetbit

Quote from: Elantric on September 13, 2013, 07:20:46 AM
Our tests show GR-30 triggers Guitar to MIDI faster than GR33 or GR55.

No need for custom Y cable really.

I would run 13 pin guitar to GR30 and use MIDI cable from GR30 MIDI Out to GR33 MIDI In.
Use an EV5 expression pedal with GR30 for GR30 volume and use GR33 onboard expression pedal for GR33 volume and run both into a small mixer.

The above method also allows full use of GR30's Arpeggiator to drive both synth engines too.


Sounds good, I love the arpeggiator on my GR30 and sorely miss it from the GR55. Would I be able to use the same method to use the GR30 arpeggiator into the GR55, or would I need a US20 to run both units?

Elantric

You need the US-20 and can NOT use the GR-30 Arpegiator with GR-55. This is because unlike all prior "Roland GR-xx" units, the GR-55 does NOT respond to MIDI Note on / off commands. (very lame restriction IMHO)

whippinpost91850

Quote from: Elantric on December 13, 2013, 12:13:12 PM
You need the US-20 and can NOT use the GR-30 Arpegiator with GR-55. This is because unlike all prior "Roland GR-xx" units, the GR-55 does NOT respond to MIDI Note on / off commands. (very lame restriction IMHO)
"Lame" just might be an understatement

Jetbit

Quote from: Jetbit on December 13, 2013, 12:01:44 PM

Sounds good, I love the arpeggiator on my GR30 and sorely miss it from the GR55. Would I be able to use the same method to use the GR30 arpeggiator into the GR55, or would I need a US20 to run both units?

@elantric
Thanks for your reply, shame about that. Guess I'll either have to save up and try and source a US20, and start clearing out the gear I don't use.........or a combination of both. Now what's to go?
VG8 - but it has so many features I love, like auto tune, ease of use, easy virtual capo......
GR30 - love the arpeggiator and the compact size
Boss ME50 - love the simplicity and I need something for the none GK guitars
Line 6 POD X3 live - easy enough to programme and tweak patches, and great with the Variax but so confusing to operate
Maybe I should ditch the Variax, I don't need 2 modelling systems - no that would be disrespectful to my wife who bought it for me
Looks like the GR30 and X3 live will have to go.