[LAU] Thinkpad R60 for Audio Update - Firewire Conflicts with Audio

[Robin Gareus]

Spencer Russell wrote:
> On 4/10/07, Robin Gareus <robin at gareus.org> wrote:
>> Spencer Russell wrote:
>>
>> > Hrm, this is problematic. I'd just about settled down to the idea of
>> > either the Presonus Firepod of the Edirol FA-66, but if there's no way
>> > to get them portable power,
>>
>> you could get or build an adapter. USB-power + 4pin 1394 to 6pin 1394.
>>
>>
> 
> I thought about that, but according to [1], Firewire supplies 30V! Can
> anyone confirm this? USB only provides 5V, so it would take more than
> just an adapter to step up the voltage.

There are different kind of "power classes" for IEEE-1394.

1394 requires the devices to regulate their own voltage.
The minimum voltage is 8V!  9.25V recommended. it can be as high as 30V.
and should not exceed a current of 1.5A... - The PCI-firewire in my
desktop just forwards the 12 Volts from the ATX power supply.. -> bug
someone with a Mac & Voltmeter ;)

Many firewire devices will work just fine with +5V -
phantom-powered preamps might pose some kind of a problem..

#robin