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RME Babyface Pro FS Portable Interface Review

amirm

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This is a review and detailed measurements of the RME Babyface Pro FS Portable professional audio interface (ADC, DAC, headphone and digital I/O). It was kindly sent to me by the company. The Babyface Pro FS Costs US $899. It is an upgrade to the non-FS version of the same product.

The Babyface Pro FS makes a hugely positive impression the minute you take it out of its nice hard case:

RME Babyface Pro FS 24 channel bus powered professional portable sound interface review.jpg

Machined out of a solid chunk of aluminum, it is quite heavy and sits still even with heavy XLR cables pulling on it.

The LED displays are bright and cheery and hard buttons are easy to figure out (I did not even bother with the manual).

The side panel has provision for external power but it is not needed. Despite all of its functionality and LED bar graph, the Babyface Pro FS is entirely "bus powered" via USB 2.0:

RME Babyface Pro FS 24 channel bus powered professional portable sound interface power and mid...jpg

The only reason to use an external power supply is for stand-alone operation or with a tablet. The DC connector is the great locking one that is used in higher-end ADI-2 Pro range of products.

Here is the other side showing two analog inputs and headphone out:

RME Babyface Pro FS 24 channel bus powered professional portable sound interface headphone con...jpg

Love the rear mount XLR ports so the cables can nicely go back to the end of the desk:

RME Babyface Pro FS 24 channel bus powered professional portable sound interface XLR In and Ou...jpg

For this review, I only used the XLR connections above and the headphone out. The input connectors are for microphone and hence high gain. I dialed down the gain using the rotary control and ran with it.

I was very pleased that the ASIO driver package was just 10 kBytes (yes, kilobytes) with no bloatware. Reliability was rock solid which is more than I can say for some other interfaces.

DAC Audio Measurements
Let's start testing each subsystem independently starting with USB In and XLR Out as if we just have a simple DAC:

RME Babyface Pro FS 24 channel bus powered professional interface DAC Audio Measurements.png


I adjusted the output to 4 volts. I was pleasantly surprised that despite being USB powered, the unit could push out over 6 volts at max volume!

At this voltage, measured SINAD of 107 dB is much better than specified 102 dB. No, this is not state-of-the-art performance. For that you need to go to higher up the line units. There is a ton of functionality here in a portable unit so performance is somewhat relaxed:

Best Audio Interface DAC Performance Review.png


Signal to noise ratio falls in the same targeted place:
RME Babyface Pro FS 24 channel bus powered professional interface DAC Dynamic Range Audio Meas...png


"FS" stands for high-performance clocking in RME parlance and we see that reflected in the jitter test:

RME Babyface Pro FS 24 channel bus powered professional interface DAC Jitter Audio Measurements.png


Nothing rises above the noise floor represented at -150 dB here.

Linearity is perfect in one channel but a bit off in the other:

RME Babyface Pro FS 24 channel bus powered professional interface DAC Linearity Audio Measurem...png


IMD performance is good:

RME Babyface Pro FS 24 channel bus powered professional interface DAC IMD Audio Measurements.png


32-tone signal at 192 kHz sampling shows similar results:

RME Babyface Pro FS 24 channel bus powered professional interface DAC Multitone Audio Measurem...png


THD+N versus frequency measured with 90 kHz wide bandwidth shows nice, organized response indicating no out of band garbage:

RME Babyface Pro FS 24 channel bus powered professional interface DAC THD+N vs Frequency Audio...png


Analog to Digital Converter (ADC) Performance Measurement
Starting with our dashboard we get:

RME Babyface Pro FS 24 channel bus powered professional interface ADC Audio Measurements.png


Nearly identical peformance as the DAC, placing the unit above average in our list of interfaces tested so far:

Best Audio Interface ADC Review 2020.png


Frequency response is more than wide enough for what you want to capture for high-resolution music:

RME Babyface Pro FS 24 channel bus powered professional interface ADC Frequency Response Audio...png


The Babyface Pro FS easily leaves high-end consumer cards on noise and distortion:

RME Babyface Pro FS 24 channel bus powered professional interface ADC THD vs Level Audio Measu...png


Feeding the ADC the same J-test signal we use for DACs allows us to see intrinsic jitter performance:

RME Babyface Pro FS 24 channel bus powered professional interface ADC Jitter Audio Measurements.png


The blue is my non-FS version of ADI-2 Pro which has some low frequency jitter. Babyface Pro FS has none of that.

Headphone Amplifier Audio Measurements
Let's start with the all important power versus distortion and noise into 300 ohm load:

RME Babyface Pro FS 24 channel bus powered professional interface Headphone Audio Measurements.png


I like to see 100 milliwatts here so that any headphone can be driven and we are not there. But what is there is very low noise and distortion.

Performance with a much lower load impedance of 33 ohm is not as good though:

RME Babyface Pro FS 24 channel bus powered professional interface Headphone 33 Audio Measureme...png


There is not a lot of power there and the reason is high output impedance:
Lowest output impedance headphone measurements.png


So the output is really for high impedance headphones that are not impossible to drive.

EDIT: specs show that the 3.5mm jack has near zero output impedance so above is not an issue in practice.

Conclusions
RME sets the performance bar at "very competent" and easily meets that with Babyface Pro FS. Yes, it would be great to have state-of-the-art performance but what is there is sufficient for its target application. The headphone output is good for casual monitoring but doesn't have the horsepower to drive difficult or low impedance headphones.

The hardware/mechanical packaging is a delight as it the ability to use it without an external power supply.

There is a ton of functionality here that I have not included in my testing. Nor other important factors such as low-latency capture and monitoring. So there is a lot more here than a simple desktop DAC/ADC.

Overall, I am happy to recommend the RME Babyface Pro FS.

------------
As always, questions, comments, recommendations, etc. are welcome.

Waited a week to mail people's boxes so today was a ship day. No less than six, mostly heavy packages had to be wrapped up, labeled and driven to the drop off location. Got stuck behind someone at the post office mailing 18 (!) little envelops wrapped in fancy wrapper to her grandchildren! In summary, I have less money in the bank and got exposed to a germ or two. If this made you feel sorry for me, please donate what you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
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Doodski

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It appears there is a spelling error @>>

THD+N versus frequency measured with 90 kHz wide bandwidth shows nice, organized response indicating no out of bang garbage:
 
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amirm

amirm

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It appears there is a spelling error @>>

THD+N versus frequency measured with 90 kHz wide bandwidth shows nice, organized response indicating no out of bang garbage:
Thanks. Corrected. Was writing drunkenly as @Thomas savage would.....
 

JIW

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According to the specs, the high output impedance is for the 6.35 mm. For the 3.5 mm, the output impedance is specified as 0.1 Ohm.

Screenshot 2020-04-01 at 01.59.28.png


EDIT: For the 3.5 mm at 7 dBu output, maximum power at 33 Ohm is 91 mW and 10 mW at 300 Ohm.
 
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bequietjk

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RME always cranks out stellar performance and just like their DAC presents a ruler flat jitter floor that is loved so much.
 

Francis Vaughan

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The output impedance seems to quite deliberate. I have an ageing Apogee Duet, which is a direct competitor, and they have a series resistor on the HP output.
I have a dim memory that for studio work there was once a recomendation that all headphone outputs have this impedance. There were reasonably solid technical reasons. Once. I should try to find the reference again. I know I had it somewhere.
 
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amirm

amirm

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According to the specs, the high output impedance is for the 6.35 mm. Foe the 3.5 mm, the output impedance is specified as 0.1 Ohm.
Ah, I looked at the specs but missed that. So that is good to see.
 
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amirm

amirm

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Xyrium

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I am a total RME fanboy, but one has to admit, this is mediocre performance. I don't buy the intentional output impedance, though I'm intrigued. I also don't feel that the power output is adequate, regardless of output impedance. That said, if this was only powered by USB, it may be beneficial to see it run with proper power connected.
 

Francis Vaughan

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My fading memory has improved slightly. I can remember the reasons given for the output impedance. They are a bit backwards in some ways, but make prefect sense.

In studio settings it is common to have everyone listening on headphones during tracking. Rather than a dedicated headphone amplifier per artist, they used (and often still use) a single amplifier fanned out to the outputs via resistors. This will isolate individual headphones from one another. The upshot is that all the headphones are driven with about 10 ohms of output impedance. Next, heapdhone manufacturers for studio work would be expected to balance their products frequency response for this output impedance. I know I came across documentation from Senheisser to this effect, and it is part of the justification for the characteristics of their headphones. In their case, easy drive, high input impedance, drive impedance insensitive. So, chicken and egg. There is an expectation that in studio settings, headphones used will be driven by a ten ohm output impedance, and the headphone design will have been balanced for this, so studio headphone amplifiers provide a ten ohm output impedance. Deliberatly and by design to a common default standard.

I will try to find the references for this. It was a long time ago.
 

Francis Vaughan

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A little bit more digging. IEC 61938:1996 recommends 120 Ohms for the output impedance of headphone amplifiers. A standard that is clearly observed only in the breach. Looking at a few studio headphone distribution amplifiers, PreSonus uses 51 ohms across their range, Mackie uses 3 ohms. The Mackie documentation explicitly shows the presence of resistors on the output. It isn't a mistake or poor design. Behringer and Art don't list theirs. The Simon headphone distribution box is still made - and indicates where all this comes from.

It is a bit of an oddity. There is clearly still an expectation in professional use that headphones are driven from a significant, if variable, output impedance, and that you will be using headphones designed to work in this setting. When you consider that the default professional headphone in many circles is still the Sony MDR-7605, it makes more sense.
 

Francis Vaughan

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@Francis Vaughan thx for the interesting info. You didn't find reference anywhere to the 10 Ohm spec did you?

No, I suspect there isn't one - I was probably misremembering the 120 ohm one. I'll dig about a bit more. It is a bit perplexing.
 
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