About the caveat of always having the Axe-FX off when connecting the MFC

[joegold]

The MFC Manual is chock full of warnings about never using any of the phantom powering systems for powering up the MFC w/o first powering off the Axe-FX and frequently states that one or both units could be damaged by doing so.

1. This is made abundantly clear on the pages describing phantom powering the MFC via the Ethernet or Faslink connection to the Axe-FX.
And this kind of makes a lot of sense to me since there's so much data and/or AC voltages going back and forth.
[But mainly it "makes sense" *to me* because I have so little experience and/or knowledge with using Ethernet for something like this. lol
Still, I never hesitate to power up my printer or my modem with its Ethernet cable inserted, when my computer is already on.
Likewise I've often disconnected and then reconnected the Ethernet cable to my printer or modem while the computer is on w/o incident for years now.
Have I just been lucky?]

2. The same warning can be found in the entries describing phantom powering the MFC via the 7-pin MIDI cable system but the warning seems a bit less emphasized.

3. And the warning is actually absent from the entries describing powering the MFC with its AC adapter plugged directly into the MFC while using 5-pin MIDI cables.

Since I'll probably (eventually) be using 7-pin MIDI with the MFC and have used similar phantom powering schemes in the past with other foot-controllers, I'm more concerned about the issues involved with scenario #2 above.

In the past, with other controllers, I've thought nothing about phantom powering up the controller while the Axe was already on and I've never had an issue with these controllers.
So I'm wondering how important it really is to always adhere to this "rule" when using the 7-pin phantom power system with the MFC?

Presumably, the same voltages and data that are involved with an Ethernet connection are involved here as well.
But....
It's not an infrequent thing, when trouble shooting something on your foot-controller, to simply unplug the 7-pin cable and then plug it back in w/o first powering down the Axe, especially since the Axe II takes so long to boot up.
If I REALLY need to be careful for the rest of my life about this sort of thing then I guess I'll just have to develop that habit.
But with me, at least, lapses can be expected.
I can understand there being MIDI communication issues/problems that might arise when doing this, but do I really need to worry about *damaging* electrical components on either the Axe or the MFC?
Ostensibly, as far as powering up the MFC is concerned, unplugging and then replugging a 7-pin cable should be electrically identical to simply unplugging and replugging the AC adapter directly into the MFC, shouldn't it?

So, what exactly is likely to blow on either the MFC or the Axe if I phantom power-up the MFC via 7-pin MIDI when the Axe is already on?

And am I correct in assuming that it *is* OK to power up the MFC with the AC adapter plugged directly in the MFC even if the Axe is already on and both units are already connected via a MIDI cable?
Or should I always power off the Axe in this scenario as well?

 

[Mark Cullen]

I am curious about this too...

 

[unix-guy]

The MFC Manual is chock full of warnings about never using any of the phantom powering systems for powering up the MFC w/o first powering off the Axe-FX and frequently states that one or both units could be damaged by doing so.

1. This is made abundantly clear on the pages describing phantom powering the MFC via the Ethernet or Faslink connection to the Axe-FX.
And this kind of makes a lot of sense to me since there's so much data and/or AC voltages going back and forth.
[But mainly it "makes sense" *to me* because I have so little experience and/or knowledge with using Ethernet for something like this. lol
Still, I never hesitate to power up my printer or my modem with its Ethernet cable inserted, when my computer is already on.
Likewise I've often disconnected and then reconnected the Ethernet cable to my printer or modem while the computer is on w/o incident for years now.
Have I just been lucky?]

2. The same warning can be found in the entries describing phantom powering the MFC via the 7-pin MIDI cable system but the warning seems a bit less emphasized.

3. And the warning is actually absent from the entries describing powering the MFC with its AC adapter plugged directly into the MFC while using 5-pin MIDI cables.

Since I'll probably (eventually) be using 7-pin MIDI with the MFC and have used similar phantom powering schemes in the past with other foot-controllers, I'm more concerned about the issues involved with scenario #2 above.

In the past, with other controllers, I've thought nothing about phantom powering up the controller while the Axe was already on and I've never had an issue with these controllers.
So I'm wondering how important it really is to always adhere to this "rule" when using the 7-pin phantom power system with the MFC?

Presumably, the same voltages and data that are involved with an Ethernet connection are involved here as well.
But....
It's not an infrequent thing, when trouble shooting something on your foot-controller, to simply unplug the 7-pin cable and then plug it back in w/o first powering down the Axe, especially since the Axe II takes so long to boot up.
If I REALLY need to be careful for the rest of my life about this sort of thing then I guess I'll just have to develop that habit.
But with me, at least, lapses can be expected.
I can understand there being MIDI communication issues/problems that might arise when doing this, but do I really need to worry about *damaging* electrical components on either the Axe or the MFC?
Ostensibly, as far as powering up the MFC is concerned, unplugging and then replugging a 7-pin cable should be electrically identical to simply unplugging and replugging the AC adapter directly into the MFC, shouldn't it?

So, what exactly is likely to blow on either the MFC or the Axe if I phantom power-up the MFC via 7-pin MIDI when the Axe is already on?

And am I correct in assuming that it *is* OK to power up the MFC with the AC adapter plugged directly in the MFC even if the Axe is already on and both units are already connected via a MIDI cable?
Or should I always power off the Axe in this scenario as well?

Are you talking about these quotes?

!IMPORTANT: Always make sure the Axe-*‐Fx II is powered OFF before connecting/disconnecting the MFC-*‐101. NEVER connect the provided AC Adapter to the MFC-*‐101 or to the Phantom Power jack of the Axe-*‐Fx II while the MFC-*‐101 and Axe-*‐Fx II are connected via Ethernet/EtherCON. Doing so could damage one or both units.

!IMPORTANT: NEVER connect the provided AC Adapter to the MFC-*‐101 while the MFC-*‐101 is powered via FASLINK. Doing so could damage one or both units. NEVER connect the FASLINK XLR connector to XLR audio inputs or outputs

To me, I read this mostly as a warning to not connect 2 power sources at the same time. Ethernet/EtherCON provides phantom power, so if using that you would not want to connect other power either via the phantom power jack + AC adapter OR AC adapter directly.

I think the same applies to using the FASLink connector.

However, now that you have pointed it out, I am also wondering about the numerous repeated warnings about not connecting the MFC while the Axe Fx is powered on.

Hopefully FAS will chime in.

Kevin

 

[joegold]

To me, I read this mostly as a warning to not connect 2 power sources at the same time. Ethernet/EtherCON provides phantom power, so if using that you would not want to connect other power either via the phantom power jack + AC adapter OR AC adapter directly.

Yes, it's about that.
And that makes perfect sense.

But it's also about this: "!IMPORTANT: Always make sure the Axe-*‐Fx II is powered OFF before connecting/disconnecting the MFC-*‐101."

At first glance that's pretty a definitive statement.
But I still think it could use some further clarification from Fractal.
And in my experience, when setting up/tearing down and/or troubleshooting various issues it's going to be quite impractical to try to comply with that warning all the time.
So I hope it's not 100% true.

 

[tas9195]

So if I have it hooked up at home and never unhook the MFC from the Axe then I can turn the axe on and off with out unhooking it as long as I don't unhook while either one is powered.

 

[guitvai1]

I hooked up my MFC 101 (Ethercon connection) with the Axe FxII already powered on and it just booted up like normal - no issues, maybe I just got lucky.

 

[joegold]

I hooked up my MFC 101 (Ethercon connection) with the Axe FxII already powered on and it just booted up like normal - no issues, maybe I just got lucky.

But if you do that some other time and something fries, you won't be covered under warranty (assuming you're still within the warranty period).
So it's probably a good idea to train yourself to NOT do that again.

I can kind of see that scenario, with an Ethernet connection, being a no-no.

But with a 7-pin MIDI cable connection it seems like it might be a lot safer to do, no?
I don't really grok how phantom power is delivered via Ethernet.
But with a 7-pin cable it's just like plugging in/out the AC adapter, which there is no warning in the manual about doing while the Axe is on and connected.

That's why I started this thread.
Some clarification from someone at Fractal would be nice.

 

[joegold]

So if I have it hooked up at home and never unhook the MFC from the Axe then I can turn the axe on and off with out unhooking it as long as I don't unhook while either one is powered.

It seems that that's how we're being encouraged to do things.
Always, for ever.
Presumably then, there's some sort of power staging that goes on when the Axe is started up that sends phantom power over the Ethernet connection (to boot up the MFC) just before the danger causing circuits in the Axe have fired up, or something like that.

And if you use phantom power over 7-pin cable you'll need to make sure that the MFC's AC adapter is always plugged into the same power strip/conditioner as the Axe, if you use the power strip's on/off switch to turn your Axe on/off.
If the AC adapter is just plugged into the wall, for instance (while you're testing things out), and then into the phantom power jack on the back of the Axe; even if the Axe is off, there will be AC going to the MFC if the Axe and the MFC are connected together via the 7-pin cable.
I.e. The electrical flow from the phantom power jack on the back of the Axe through the 7-pin cable is not switched on or off by the Axe's on/off state.

So be careful boys and girls.

 

[shasha]

Not that this is exactly what you are looking for, but the whole issue with using AxeEdit with the MFC on being a potential issue I decided to get a cheap 1RU rackmount power strip with 8 on/off buttons (one for each outlet). I leave the AxeFXII plugged into the MFC101 via 7 pin MIDI, but I can power everything on/off individually with the flip of a switch. And yeah part of that is because the MFC has no on/off button so this kind of works around that.

It works great because I have some other things like powered monitors and a control room monitor that has a wall wart....I can turn all of this crap on or off on it's own which should in theory save on the electric bill.

Amazon.com: Chauvet PC-08 15A Black-Faced Circuit Breaker: Musical Instruments

Apparently it's on sale for dirt cheap right now. Now it's not a power conditioner, it's only got a fuse so don't expect it to be more than it is, but it's pretty handy.

Oh and a couple of these are really handy for connecting wall warts to the back of a 1RU space.

Amazon.com: 1-Foot Extension Power Cable, 5-Pack: Electronics

 

[Admin M@]

It's a precautionary warning against mishap. Being careless with an RJ45 that's spouting 12VAC can net you some trouble.
The warning still holds for MIDI and probably FASLINK connectors, even though the risk there is probably reduced.

If you fry your Axe-Fx through a careless MFC connection while the power is on, the damage is tell-tale and not covered under warranty.

 

[joegold]

It's a precautionary warning against mishap. Being careless with an RJ45 that's spouting 12VAC can net you some trouble.
The warning still holds for MIDI and probably FASLINK connectors, even though the risk there is probably reduced.

If you fry your Axe-Fx through a careless MFC connection while the power is on, the damage is tell-tale and not covered under warranty.

Thanks for clarifying Matt.

Just for the record though, because of the problems I'm having that you're helping me with at Fractal Support (as detailed in another current thread I have on the forums)...
*I* have *never* connected an Ethernet cable to my MFC while the Axe was already on.
So this can not be the source of the issues that I seem to be having with my Axe's Ethernet port.

Still.
I think this design will be troublesome for both you folks at Fractal and for your customers in the long run because being that careful *all the time* just isn't practical for most of us.
I wouldn't be surprised if a whole bunch of new MFC owners have tried to phantom power their MFC's w/o even first consulting the owner's manual and seeing these warnings.
If they haven't all fried their Axes or their MFCs they might just be lucky.
[Note: *I* did read those warnings before I tried phantom powering my MFC, especially when using the Ethernet cables.]

If there's ever anything you folks can do to minimize this danger in future firmware updates (unlikely) or in future MFC/Axe-FX designs (more likely), IMO, it'd be a good idea to do it.

E.g. Are DC power supplies any safer in this regard?
Are AC power supplies that are less than 12v AC any safer in this regard?
Is there some sort of a preventative fuse or circuit breaker you could add to the electrical circuit?
Etc.

 

[tas9195]

It seems that that's how we're being encouraged to do things.
Always, for ever.
Presumably then, there's some sort of power staging that goes on when the Axe is started up that sends phantom power over the Ethernet connection (to boot up the MFC) just before the danger causing circuits in the Axe have fired up, or something like that.

And if you use phantom power over 7-pin cable you'll need to make sure that the MFC's AC adapter is always plugged into the same power strip/conditioner as the Axe, if you use the power strip's on/off switch to turn your Axe on/off.
If the AC adapter is just plugged into the wall, for instance (while you're testing things out), and then into the phantom power jack on the back of the Axe; even if the Axe is off, there will be AC going to the MFC if the Axe and the MFC are connected together via the 7-pin cable.
I.e. The electrical flow from the phantom power jack on the back of the Axe through the 7-pin cable is not switched on or off by the Axe's on/off state.

So be careful boys and girls.

Thanks for the response. as far as using a 7 pin midi. I have one from my rocktron that I used with the midi mate will that work with the MFC. It is arriving today so I am trying to figure out how to hookup to the axe fx via Ethernet etc....

 

[joegold]

Thanks for the response. as far as using a 7 pin midi. I have one from my rocktron that I used with the midi mate will that work with the MFC. It is arriving today so I am trying to figure out how to hookup to the axe fx via Ethernet etc....

http://forum.fractalaudio.com/mfc-discussion/95005-mfc-teething-pains.html

Hopefully you won't have any of the issues that I've been having with my 7-pin cables.
But you also might end up having to order a cable from Best-Tronics.
Keep us posted please.

 

[tas9195]

I will

 

[axel]

This confuses me just a little, because even when the Axe Fx is powered off, there is still power on the MIDI cable when using a phantom power source (ie. adapter plugged into Axe Fx). So, does having the Axe Fx off before connecting the foot controller only apply when using the Axe Fx onboard power supply via Ethernet or FASLINK? That would make more sense to me, since when using an AC power adapter plugged into the phantom power jack, it appears to just be hard wired directly to the Axe Fx MIDI power pin, and not passing through any Axe Fx circuitry.

 

[dr bonkers]

think of the power the AF2 supplies the MFC in the same way that a pro recording console supplies +48 vdc to condenser mics. In the studio, you would never engage phantom power and then try to plug the live xlr into the condenser mic, as it could blow up the mic capsule, mixer phantom power supply, or both if there is a power arc (not to mention blow up the studio monitors woth the loud pop an arc of that strength would make). Some things when dealing with phantom you just don't do and it is realistic to think that if you know the dangers & damage if you lapse in your protocols.

 

[joegold]

I will

You mean you're having the same issues with your 7-pin Rocktron cable that I'm having with my 7-pin cables?

Q. When you try to phantom power the MFC with your Rocktron 7-pin cable, do all the lights on the MFC light up and stay lit but it never actually boots up and there's no communication at all with the Axe?

As I detailed in that other thread, that's what's happening to me with my 7-pin cables.

I didn't really want to pay for the faster shipping for my new, Fractal approved, 7-pin cable from Best-Tronics.
I sure hope it solves the issue.
Otherwise I'll be in Fractal-Support limbo for a while.
But I won't know for at least another week.

 

[joegold]

This confuses me just a little, because even when the Axe Fx is powered off, there is still power on the MIDI cable when using a phantom power source (ie. adapter plugged into Axe Fx). So, does having the Axe Fx off before connecting the foot controller only apply when using the Axe Fx onboard power supply via Ethernet or FASLINK? That would make more sense to me, since when using an AC power adapter plugged into the phantom power jack, it appears to just be hard wired directly to the Axe Fx MIDI power pin, and not passing through any Axe Fx circuitry.

That's what I thought too.
But read Matt's message in this thread,
He says having the Axe powered down is still an issue even if you're using the 7-pin phantom powering system.

So I guess it's best to have your Axe and your MFC AC adapter *always* on the same power strip and *only* power up via the strip's switch.
But one day we're all gonna forget about this and then I guess it'll all come down to luck.

 

[joegold]

think of the power the AF2 supplies the MFC in the same way that a pro recording console supplies +48 vdc to condenser mics. In the studio, you would never engage phantom power and then try to plug the live xlr into the condenser mic, as it could blow up the mic capsule, mixer phantom power supply, or both if there is a power arc (not to mention blow up the studio monitors woth the loud pop an arc of that strength would make). Some things when dealing with phantom you just don't do and it is realistic to think that if you know the dangers & damage if you lapse in your protocols.

Yeah.
But this is only 12v.
And there is no issue, I believe, just plugging the MFC's AC adapter, with those same 12v, directly into the MFC while the Axe is already on and connected via 5-pin MIDI.
[If I'm wrong about that I hope Matt will correct me.]

Assuming that that's true, I really don't see the difference in connecting the 7-pin cable phantom power system to the MFC while the Axe is already on.
It should be the exact same thing, electrically speaking, as plugging the adapter right into the MFC while the Axe is already on and connected via a 5-pin MIDI cable.

Of course I'll adhere to these warnings, especially while my MFC is still under warranty, because I really don't want to be the cause of anything blowing.
Shipping stuff back to Fractal for service is a real drag from anywhere but it's even worse from Canada.