Do I read this correctly - that the Babyface has no separate power socket, and that dc power is only supplied via the USB connector?  And the external power supply voltage must be 5.0V ? 0.5V.
   
Does this mean a special USB cable is needed if power is to be supplied other than from the host computer.  Is this also 'optional'?

Hi,

First some background:
Just got a new Mac book pro(mid 2010, i7, 17").. Anyway, my current problem is that when I connect a firewire soundcard to it, the MAC itself will start doing somekind of electrical whistling, whining noise from upper left corner of the machine. Most probably from parts giving power to the firewire port. A connected firewire hard drive with external power will not produce any noise from the Mac. (Tested Apogee Duet and TC Electronics sound cards). I have also tested on other MBP of more or less the same model as mine and also then it seems they are not quiet. Which is why I believe changing parts in the Mac will not give any less head ache.. Mac support does not recognise the problem, which is odd since there are others on internet that tried changing there machines for the exact same reason.
I also believe that the problem hasn't something to do with with the actual current that is consumed by the peripheral, since the noise continues 2-3 seconds after the FW cable is removed. I presume the noise comes from that the peripheral asks the Mac to put some current on the port, and just enabling these power circuits in the Mac will cause this noise.

..a lot of unconfirmed theories, but anyway..
so my question is now - that is if the noise comes from giving power to peripherals - does the baby face ask for power from the USB, even if it has external power?
Maybe it works better anyway since its USB etc - but it would be nice to know what my changes are out of a powering aspect ;-)

/John

Try turning *off* the internal speakers. This should give an audible "pop" sound and the residual noise/hiss should vanish as well (put your ears close to the left speaker). I noticed on my 2009 17" model that the other noise turns down considerably as well.

If your 2010 model does not "physically" turn off the speaker by using the Mute button then try turning off the internal audio interface as playback device for system sounds. OS X turns off the speaker 30 seconds after the last sound was played over the internal interface (as far as I remember by corresponding analysis from a few months ago).

Last but not least compare the noise when the MBP's PSU is connected to when it's disconnected. Try both a power outlet with and without grounding for a change.

Another point is that the noise you are describing seems to be related to the audio-buffer size of the external interface you are using (doesn't matter if FW or USB). The frequency of the whining is directly related to the audio-buffer size chosen. Funny stuff, kind of. HeadScratch ed:

Please contact your RME retailer or local distributor. The PSU will not increase phones volume, though.

Regards
Daniel Fuchs
RME

+1

I guess the most "official" one would be this one then:

http://www.thomann.de/gb/rme_cardbus_netzteil.htm

?

This looks interesting. Has any testing been done on this?

The two interfaces referred to are the Babyface & Fireface UC.

(I don't know if it has been mentioned in another thread)

PS: interface is a Baby Face and power cord is: ac 100-240, 50-60 Hz 12V 1000 mA

Jeff, Thank you for the prompt answer

The polarity is correct, and the dimensions of the plug are correct.

NTCB-US is the power supply, NETZ-CB is the line cord. This is not specific to the Babyface, it's the same PSU used for many RME products.

Good question.  I just purchased a Babyface Pro FX and wondered where the external power brick was myself.  Although they are touting this as "fully USB bus powerable", I don't like placing the extra load on my computer's internal USB bus.  The USB bus is usually the first thing to die on the motherboard due to excessive loads created by powered USB devices.  Once the USB bus dies you usually end up having to rebuild the entire system.  The SIMPLE ANSWER to your question regarding what external power supply to use with the RME BabyFace Pro FX is:

RME NT-RME-2 Lockable

Please note that there are TWO versions of the NT-RME-2.  There is a "lockable" version and a "regular" version.  I have NO IDEA what they are referring to by "lockable" but the lockable version is the one designed for use with the BabyFace Pro FX.  The other one appears to be for older versions of the BabyFace.

The lockable version has a groove on the plug so that the plug can be locked by turning it after insertion to prevent it from slipping out accidentally.
When plugging in, you have to turn the groove so that the plug can be fully inserted. The locking is achieved by a slight rotation (approx. 90°).
Older devices did not have this, for them you just take the PSU without locking. For the newer devices, of course, it makes sense to get the PSU with locking, there I would then stay with the original RME power supplies, so that everything fits together.