DIY phantom power cable 7 pins Axe II to 5 pins to footcontroller

[manu68]

Hi,

Some months ago, I have built my footcontroller, based on a MIDI CPU platform.
Now, I have in project to had phantom power to this footcontroller, just because it would be a cool feature :lol

My footcontroller have a 5 pin female connectors wired as in the pictures below.
Currently, the pin 1 and 3 are not in use on my footcontroller midi out , and could be used to bring the power from the pin 6 and 7 of the Axe FX II to the DCin +/G of the midi cpu board. (Am I right ??)


If I understand well after reading some other thread, I need to "customize" a 5 pins midi cable to a 7 pins (Axe FX) to 5 pins (footcontroller) midi cable. (Am I right ??)

I currently use a boss type 9V pedal alim, directly into the footcontroller. Also I suppose that I could the same 9V alim directly into the phantom power connector at the back of the axe FX . (Am I right ??)

Just to be sure, will it work if : (based on the 7 pin configuration below)
May I connect pin 7 of the Axe FX II to pin 3 of my footcontroler ?
May I connect pin 6 of the Axe FX II to pin 1 of my footcontroller ?

 

[paranoid]

yes you can phantom thru the 7 pin input on the axe fx, but the power adapter is 2.5 mm for ac power not dc. and yes you would have to build the cable. rocktron has a phantom cable 7 pin to 5 put it has a little y cord on the 5 pin end that plugs the power to the controller. I myself built a short adapter to go in between the axe and the midi cable to connect my power to, then I use standard 5 pin cables on each side of it.

 

[manu68]

Thanks for the information, especially regarding the power adapter.

I power currently my footcontroller with this alim ; 9V DC , 500m Amp / + outside
Thomann NT AC/PSA - Thomann France
If I understand well, I can not use it with the power adapter Axe FX II, even with a "right" connector. ??

I could not found information regarding AC power in the Axe FX II manual.
Thanks for the precision.
I have to look for some further precision because after lookin at the rocktron cable + AC power, it is not so clear anymore :lol

I also have this alim , but again same problem because of AC current.
Harley Benton PowerPlant Junior - Thomann France

 

[Evz]

Hello,

I don't know the specs of how the AFX's adapter input is wired, but my assumption is that the terminal is wired arbitrarily to pin 6 & 7. The reason AC is preferred is that you don't have to worry about which pin is positive and which is negative, thus you can test it by using voltmeter set to resistence, and check which pin (6/7) is connected to which adapter terminal (inside, or sleeve).

Personally, I would not use a DC adapter, and run AC instead to comply with the AFX's expected operation, and on the controller side, add a small rectifier + voltage regulator from the AC signal you would get on pins 1 & 3 (look up a diode bridge similar to a DB101 and a linear voltage regulator such as a LM7805 for 5vdc or LM7809 for 9vdc). Further, the use of a rectifier & regulator would technically allow you to run an AC input power source and DC.

Regarding running a DC voltage vs AC voltage through a data cable, I'm not too sure of the consequences of signal degradation in either case, though if I recall correctly, AC is more safe to the touch should a cable break?

Anyway, hopefully this helps.

Regards,
E

 

[manu68]

I didn't realise myself that phantom pover from Axe FX II was AC.

I will go the "easiest" way and built a small interface box (midi 5 pin + DC 2.1mm female to plug my current 9V DC alim) between the axe FX II and my pedalboard, I will do phantom power 9V DC through a Din 5 pin cable from this interface box and not from the Axe FX II itself.
I have plenty of place in my rack to place this small box. No problem.

I will not use the pin 6 and 7 from Axe FX II at all

Thanks for the information. Or I would have not thought about this 2.5mm AC problem.

 

[paranoid]

there is no phantom power to the midi in the axe fx you have to power it through the 2.5 mm power adapter conection on the back of the axe. 2.5 mm is an a/c adapter size, d/c mostly is 2.1 mm. but my self I didn't want to take a chance on any thing hurting my axe fx ( my nickname is paranoid) I bought a female female 5 pin midi coupler and took it apart and made an adaptor to connect my power for the phantom and removed the powered pins on the axe side( to not send power to the axe) and glued this together in to the rack case. the axe fx end is only 3 foot and the pedal end is 25 so I hope to never get them crossed up.

 

[tgorycki]

With my previous foot controller (ART Ultrafoot), I used a Rocktron RDMH900 7 pin to 5 pin phantom MIDI cable to do the trick. I had to change out the barrel plugs on the end of the power supply (wall wart), which plugs into the back of the Axe-Fx II, as well as the barrel plug on the end of the Rocktron cable (you may be able to just use the one you cut off the end of the power supply). Most importantly, check your polarity before wiring everything up. An inexpensive voltmeter can easily accomplish this (you can find them as cheap as $10). If you don't already have a soldering iron, pick up a low wattage (30 watts?) iron for less than $10, get some solder and don't forget the heat shrink tubing to insulate your connections.