PHANTOM POWERING THE GT

Alexander,
I've used the connections as described in the Mastermind GT manual:
6%20Pins%20XLR%20-%202Way%20Midi%20%2B%20Power.png

So you can connect the power from the adapter straight to pins 1 & 2
 
rjmmusic said:
It depends on the length of cable you will be using and the model of GT you have. If you need a long cable (8m or longer) and you have a GT22, it might not be able to handle the current draw. In that case, I'd ask Best-tronics to use two wires for each power connection. If you talk to Brad at Best-tronics, he'll know what i'm talking about and would be able to get the right cable built.
Click to expand...

Ok, so I'm talking to Brad at Best-tronics and ordered a phantom power cable. Brad asked about the polarity of the midi cable. I see that wth the XLR midi the polarity doesn't matter, is that the same with the DIN midi cable, or which one of pin 6 and 7 needs to be positive and negative?

Thank you
 
Our products don't care about polarity. I always build cables with the power wires wired straight through unless there's a particular need to swap them.
 
My Rolls RFX-MP26 5-pin to 7-pin phantom power box (see PDF) shorts pins 1+7 and 3+6 together. Would there be any issue with using this with the Mastermind GT?

I'd use a 7-pin cable on the MMGT side of things and 5-pin on the Fractal side.

===Edit===

I found this in the "Specifications" section of the Owner's Manual. I had been looking elsewhere in the OM.
"
Phantom Power Accepted over pins 6 and 7 of the MIDI Out jack
GT/22 only: Accepted over pins 1 and 2 of the XLR MIDI Out jack
Do not connect phantom power at the same time as the AC adaptor!

Do not use pins 1 and 3 for phantom power! "

I guess that I'll have to go beep this thing out and see if I can cut the connections. Or does the above quoted statement pertain only to the GT22 and the XLR connector?
 

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Pins 1 & 3 are used for bidirectional MIDI support, so you definitely don't want to connect phantom power to them. With the "Remote" setting turned off on the GT, a relay disconnects those pins for this very reason, but it's still safer to not send power to those pins at all. I recommend modifying a cable or getting a cable made that has pins 1 and 3 not connected.
 
Hello Ron,

Thanks for the reply. I just finished going into the box and re-wiring it to have each pin going straight through; except for pins 6 & 7 on the side going to the Axe-FX, which are now floating. As you mentioned, I figured that it was the smartest way to go about things.

Thanks again for your support,

Kent
 
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HI
I have Axe FX II XL + and Mastermind GT16
Can I use the Phantom Power Adapter PPA - DIN7F -2 ( the adapter I have ) to connect to ax fx ?
Do I need to buy a Phantom Power Adapter PPA - DIN7F - 1 to connect it?
Thank you for your help!
 
Can you post links to the products that you've mentioned? If not, how about some photos? Google shows me nothing regarding these ID numbers.
 
These are the numbers from the manual 3.0, and there are also drawings of adapters, you can see it just in the user manual

http://www.rjmmusic.com/manuals/Mastermind GT Manual-3.0.pdf

There is `Setup with a Fractal Audio Axe Fx - page 12 (Phantom Power Adapter PPA-DIN7F-1) and Setup with a Kemper Profiling Amp - page 15 (Phantom Power Adapter PPA-DIN7F-2)
I have Axe FX II XL + but , unfortunately, the phantom power box for Kemper with two outputs and don't know if I can connect it?
`
 
You can use the two output box with an Axe-Fx, no problem. We just recommend the one output box because it works just as well and you can use one less MIDI cable. The Kemper does not have bidirectional MIDI capability, so it requires the two output box.
 
Is there brand of cable that's available in the States (Belden, Mogami) that works well for the higher current for the GT22 and still passes the data well?
 
Mogami's 8-conductor cable uses very thin conductors and I don't recommend it. They may have cables with fewer conductors that do better, but I have not tried them.

I prefer to use something like Belden 9538, and use two wires in parallel for each power connection. That's good enough to do 50 foot cables that work correctly.
 
Hello from France.

In order to connect GT16 to my AxeFx II XL+, I bought this cable (4 pairs 24AWG with shield)
I'd like to connect phantom power pin 6/7 with 2x2 wires, but with my cable, I have 8 wires + shields, and I need 9...

I saw few times pin 2 is not needed, can I let the pin 2 free on both plugs and use its wire to connect it on power pin (6 or 7).
Other idea, can I use the shield as one wire ?

About shield, there is one for each pair and one all around. What do you think about ?
Do I have to connect some of them on plug's body only on one side or both ?
And what about if I use them for phantom powering ?

Thanks for your help
Franck
 
We use the shield wire for pin 2 (which is what the MIDI spec recommends), then you have enough wires to use two for each phantom power pint. The connector shields aren't connected to anything (again, per the MIDI spec).
 
Hi,

Great news to use pin 2 for shields. :)

But I'm not familiar with shields. Do you think it's a good idea to connect all shields on pin 2 ?
My cable has one shield per pair and one all around.
What do you recommend in this case ?
I imagine :
* Only midi wires (4/5 and 1/3) >> shields on pin 2 only one cable's extremity / power wires 6/7 shield on the other plug side. And external shield ?

Does that make any sense ?

Franck
 
The MIDI spec recommends that the shield wire be connected to pin 2 on both ends of the cable. MIDI inputs are not supposed to have pin 2 connected to anything inside the device, so that prevents ground loops. MIDI outputs should always have pin 2 wired to ground inside the device.
 
Thank you very much for your help. Everything is clear now.

If I did not bought my cable, I'll take yours Mr.E. It seems the best !

Franck
 
Ron,

Just got my GT22 :)
I tried it with a 5 pin Midi cable and everything works fine.
But when using my cable like I described in my earlier post, things don't work.
Does the polarity of the MIDI pins matter?
It sems like the only thing that can be wrong is this.
 
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