What is 6 pin firewire 1394a voltage?

What is the specification of 6 pin 1394a power?

I know it can be up to 40v.
Do firewire cards regulate the voltage to the device somehow? Or is the regulation done on the device?

If someone could give me a straight or not so straight answer that would be great.

Or if you think we could visually diagnose how much voltage my device can regulate from the firewire port that would be great. Its pretty sparse 2 layer board with few surface mount components.
I'll start going about this myself if no one has any suggestions or warnings and eventually I'll try routing it to my 19v laptop power supply.

My device is a presonus sound card (any comments about how this may affect phantom power or preamps appreciated) it takes a 6 pin cable, but can be run on a 4 pin plus a 16vac psu. It also runs on a 12vdc psu.

 

From Wikipedia the voltage is listed as unregulated, and nominally around 25 volts (24-30). Devices are supposed to be able to pull about 7-8 watts from the port. Notebook implementation is obviously usually limited by the battery, so probably would be something more like 9 volts to 14-15 volts maximum.

So, basically, it seems like regulation should be done from the device.

 

What, don't you mean, macbook implementation is limited by the battery?
I was wondering if they had some special inverters up to 30v cause they're macs, probably not...
Otherwise no laptops ship with 6 pin AFAIK...

I was just going to solder it to my DC jack or something, tho I guess I could use my battery. I had it running OK on 5v once plugged into an firewire cardbus adapter.

 

I think the M6500 has a 6-pin powered 1394 port. I'd agree it isn't common, though.

 

Whoah!!!
I have one of those!!

My quad core capable MSI gx620 is livebook, I had NO idea they were built for audio production. Man thats crazy.

I wonder if it has a custom BIOS, I'm going fix this baby up now and check the DPC latency
Thanks for the info.

That said, those laptops aren't anything special at all, they don't come with built in 6 pin firewire. I have a adapter, anybody can get that. Even if you aren't annoyed about it sticking out, they need an external power source so its really not any different than using a 4-6 pin cable.

I just want to be able to plug in and use my sound card with 1 normal 6 pin firewire cable. I will definitely achieve that. At this point I see very little reason not to rewire my 4 pin connector to a 6 pin one & my 19v PSU voltage.

 

I'm tapping straight to my DC jack. I think it will be enough voltage considering the 16v psu it shipped with.

And my laptops already overload the PSU and shutoff sometimes when I overclock (and run furmark + superpi).
I'll go ahead and solder a tip on my 180w adapter while I'm at it.

Thanks again for the advice.