1 Topic by RME_fan (edited by RME_fan 2022-05-21 04:52:44)

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Topic: Sources that claim ADI-2 sounds better than Babyface Pro

There are various sources that claim a sound quality difference, and some claim that there are only differences in the features/user interfaces.

Let's start with an example, so that we can analyze this confusing situation in a proper way:
"In our latest tutorial, we show you how to combine the RME ADI-2 DAC FS and ADI-2 Pro FS R with an audio interface – such as the RME Babyface Pro FS – to take advantage of the incredible ADI-2 conversion for a high-end monitoring and headphone solution."
https://www.synthax.co.uk/latest/2021/1 … interface/

And indeed, RME is making a similar distinction in the quality of the conversion itself by calling ADI-2 "high-end", "New Experience in Sound and Quality", "reference AD/DA converter" and "crystal clear and transparent sound signature":
https://www.rme-audio.de/adi-2-pro-fs-be.html

The contrast is quite extreme when you compare with this message from RME:
"There are no differences in frequency response or "sound quality" by design, much less are any RME devices supposed to have a "character" of any kind. Your test surroundings also seem less than ideal... Also, expectation bias may play its part."
https://www.forum.rme-audio.de/viewtopic.php?id=25728

2 Reply by ramses (edited by ramses 2022-05-21 07:41:51)

  • ramses
  • DAW Mastermind
  • Online
  • From: UTC+1
  • Registered: 2012-10-14
  • Posts: 13,199

Re: Sources that claim ADI-2 sounds better than Babyface Pro

There is no absolute truth because the basic requirements are always different (hearing ability, premises, equipment, daily form). For many, the truth is that they can't tell any difference in sound. But that doesn't mean that there aren't any.

There are also technical differencies between products. ADI-2 DAC/Pro have switchable D/A filters with certain properties, different latencies, other devices do not, a recording interface also needs fast converters, among other things.

Marketing will always emphasize the special capabilities and features inherent in the devices.

KaiS has already reported why he prefers the D/A filter slow and I also could hear differncies between D/A conversion of ADI-2 Pro and Accuphase some years ago. There I found a setup which made it possible to switch between both quickly. The differences were small but recognizeable. Accuphase's DAC converter board sounded like NOS on the ADI-2 Pro.

That means there are some differences, but they are only really relevant for a few or are even critical for business.

I wouldn't start "putting words on the gold scales" now, everyone sees it from their own perspective.

But what is the reason for your posting? How can I help you?

If you are unsure whether the ADI-2 DAC/Pro in your setup will enrich your sound, then you should try it out at home in your premises.

Quite apart from the sound, I think you could enjoy many of the special features of the ADI-2 DAC/Pro, e.g. auto reflevel, dynamic loudness, slow ramp-up of volume if you plug phones or switch channels, sample rate converter, .. . I personalyl enjoy these and other features every day.

If you are recording and need a digital mixer to route audio my recommendation will always go into the direction to start with a recording interface with TotalMix FX. If you have on top of that some additional bucks left .. then go and enhance your monitoring with the ADI-2 DAC/Pro. Whether it really enhances the sound for your in your premises and with your equipment I can't promise you. But you can be sure its of finest quality and you will get a lot of very useful features.

Additionally you get more safety, that accidently pulling a fader to 0dB in TM FX will not harm your ears and equipment.
Especially useful, if your active monitors have no or only limited volume control.

If you connect the ADI-2 Pro to a digital port of your recording interface, then you can keep all faders at 0dB and then use the volume control of the ADI-2 Pro. It acts there like a monitoring contoller or a "big knob" controlling your final volume.

For some people that definitively need a recording interface with TM FX it might make more sense to get a BBF Pro and then to get better monitors / phones, if sound enhancement is the only priority, because there you have much more headroom for improvements compared to converter differences.

I hope my answer gives you inspirations into what direction to go or to perform tests of your own to exactly know what you will get.
[ EDIT: thanks KaiS for jumping in here how to test properly, see next posting ]

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14

3 Reply by KaiS (edited by KaiS 2022-05-21 10:00:46)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

For a valid comparison of any kind, two things have to be 100% excluded:
- Expectation bias.
- Level difference.

Without taking care of this, every result is worthless - in the row of the thousands and thousands of pseudo - “reviews” and reports you find all over the net, pure mumbo-jumbo.

Who of those reporters, do you think, took the extra mile to do a proper A/B?
Not even the self declared YouTube experts I promise - at least I never saw them showing it.


Scientific approach is boring, doesn’t get you followers, the majority of people are not interested.

What’s more boring than to tell:
The $5000 thingy sounds the same as the $200 one ?!
More than that, it gets you hostility from the “belivers”, the audiophile community.
That’s why a reviewer HAS TO REPORT A DIFFERENCE.
Valid testing comes across this intention.
Of course, the more expensive, more exotic ALWAYS has to sound better, no exception allowed.



There‘s nothing more simple than doing a level controlled, blind A/B comparison.
What you need costs below 100 bucks:

• A simple A/B switchbox with 2 ins, and 2 outs - one for the listening device (speaker amp, headphone) and one for an AC meter.
• Two sets of visually identical interconnect cables.
• An AC Voltmeter with a 4 digit resolution and some adapters to connect it.
• A source for a 400 Hz or 1 kHz sinewave: a free generator app, Youtube, streaming, download etc.


How to:
1. Plug the cables.
2. Set both DUTs (Devices Under Test) to exact same level, within 0.05 dB / 0.5 %, or better.
The measurement must be done while each DUT drives the load, to exclude level differences from loading.

3. Remove the cables, then replug them without knowing which one is which.
This is the “Blind” part, and this is why the cables need to be visually identically.
4. Listen, switch around, take notes, only after that identify A and B.
5. Repeat from step 3., several times until the number of tests becomes statistically relevant, e.g. 8 out of 10 point in the same direction.

If you have both, a BabyFace and an ADI-2, do it!
It’s educational and will change your life - a little.
If you need further help on this, ask.


I did these type of tests with DA-Converters, Headphone- and Speaker-Amps and other, Pro-Audio recording studio stuff 1000s of times.

The results are often disillusioning:
- There is no audible difference, or
- The difference is very tiny, at the edge of audible, or
- There is a difference, but it’s hard to say what’s better, or
- Sometimes there’s a real, obviously describable difference that needs to be further investigated.

KaiS's Website

4 Reply by RME_fan (edited by RME_fan 2022-05-21 14:43:38)

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Re: Sources that claim ADI-2 sounds better than Babyface Pro

ramses wrote:

But what is the reason for your posting? How can I help you?

If you are unsure whether the ADI-2 DAC/Pro in your setup will enrich your sound, then you should try it out at home in your premises.

Thank you for your wonderful analysis, so it is not certain that the marketing from RME about crystal clear and transparent sound signature from ADI-2, makes a significant difference from Babyface Pro FS.

The reason for asking was that I have bought the ADI-2 Pro FS R still in the unopened box, but I found an external phono stage for digitizing my records with a high-end moving coil cartridge, and that one only has enough gain for a 20 millivolt microphone signal. I looked at impedance matching for the microphone gain stages available from Thomann, but the Babyface Pro FS seems like the best way to do this if there is practically no difference in its sound quality compared to ADI-2.

Suggestions about what you would do in this situation are greatly appreciated.

5 Reply by KaiS (edited by KaiS 2022-05-21 14:56:14)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

RME_fan wrote:
ramses wrote:

But what is the reason for your posting? How can I help you?

If you are unsure whether the ADI-2 DAC/Pro in your setup will enrich your sound, then you should try it out at home in your premises.

Thank you for your wonderful analysis, so it is not certain that the marketing from RME about crystal clear and transparent sound signature from ADI-2, makes a significant difference from Babyface Pro FS.

The reason for asking was that I have bought the ADI-2 Pro FS R still in the unopened box, but I found an external phono stage for digitizing my records, and that one only has enough gain for a 20 millivolt microphone signal. I looked at impedance matching for the microphone gain stages available from Thomann, but the Babyface Pro FS seems like the best way to do this if there is practically no difference in its sound quality compared to ADI-2.

Could you please tell the model of the Phono stage and the Phono Pickup you do use?

20 mV output is extremely low for an RIAA preamp, maybe it’s just an MC Pre-Pre?

Do you want to do the RIAA equalization in software, instead of using an RIAA amp?


Side Mark:
In a Hifi environment the ADI-2 Pro makes much more sense than a BabFace, in the long run.
I think about the functionality, not only the undoubtedly immaculate AD-DA conversion capability.

KaiS's Website

6 Reply by RME_fan (edited by RME_fan 2022-05-21 15:25:45)

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Re: Sources that claim ADI-2 sounds better than Babyface Pro

I looked at buying the Ortofon MCA-76 that shows up rather often on the second-hand market. It's called a moving coil amplifier, and has good impedance matching for a modern Ortofon MC Quintet cartridge.

The output from the cartridge is something really low like 0.5 millivolt and then, the phono stage has 34 dB. I used an online calculator to get roughly 25 millivolt, so I think that is right.

Isn't it bad to add RIAA in software, because I read dynamic range is lost from the signal source? Maybe, someone knows. On closer inspection of seller descriptions of MCA-76, it is not certain that there is RIAA built in.

7 Reply by KaiS (edited by KaiS 2022-05-21 19:19:40)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

RME_fan wrote:

I looked at buying the Ortofon MCA-76, an old phono stage that has good impedance matching for a modern Ortofon MC Quintet cartridge.

The output from the cartridge is something really low like 0.5 millivolt and then, the phono stage has 34 dB. I used an online calculator to get roughly 20 millivolt, so I think that is right.

Isn't it bad to add RIAA in software, because I read dynamic range is lost from the signal source? Maybe, someone knows. I believe that the MCA-76 has RIAA, but I don't know.

Ortofon MCA-76 is a MC-Pre-Pre without RIAA EQ.
Lookin at the specs only, Ortofon MCA-76 and MC Quintet, it seems like a good match.
You should end up with about 80 dB S/N ratio, significantly above what a vinyl disc offers.

What you need is about 20-30 dB of extra gain to fully drive ADI-2 Pro.

Babyface’s mic input will probably NOT work very good:
It’s low input impedance of 2 kOhm (well suited for mic’s BTW) will load MCA-76’s simple two-transistor output stage too much and significantly degrade the quality.
MCA-76 is built to drive a phono input of 47 kOhm, not mic pre’s.


Another important thing to consider:
The MCA 76 is very old now (~45 years) and probably needs a recap to work to specs (it’s stuffed with caps!).
It even contains a lot of tantalum electrolytics that are about to completely fail after such a long time.


Considering all this and the fact that a used Ortofon MCA-76 doesn’t come cheap, you might finally be better off with a Lehmann Audio Black Cube or such, that even contains a high quality RIAA EQ.
https://www.auditorium.de/vinyl/kompone … 9QEALw_wcB

KaiS's Website

8 Reply by KaiS (edited by KaiS 2022-05-21 17:14:25)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

Another, bit crazy idea that might turn out to work nicely:

Connect the Ortofon directly to the mic input of BabyFace, prefereably fully balanced, to avoid hum.

Calculating from the spec’s you might end up with about 65 dB or better S/N ratio, BEFORE (software) RIAA EQ.
Software based RIAA EQ further improves that in the treble range, where noise is most annoying.

KaiS's Website

9 Reply by RME_fan (edited by RME_fan 2022-05-21 20:00:55)

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Re: Sources that claim ADI-2 sounds better than Babyface Pro

Thanks. A seller also told me that there is no RIAA in the Ortofon MCA-76, so I have no reason to buy it. A normal preamplifier with a phono stage will work fine. Output impedance of the old cassette decks is also 1 kilo-ohm, so the impedance matching from plugging straight in to the ADI-2 wouldn't work if I want to digitize old cassette tapes anyway.

I will keep my ADI-2 Pro FS R as there is no reason left for me to seriously consider buying the Babyface Pro FS.

10 Reply by KaiS (edited by KaiS 2022-05-21 21:08:41)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

RME_fan wrote:

Output impedance of the old cassette decks is also 1 kilo-ohm, so the impedance matching from plugging straight in to the ADI-2 wouldn't work if I want to digitize old cassette tapes anyway.

I will keep my ADI-2 Pro FS R ...

Good decision.
And yes, the cassette deck will perfectly work, connected directly to ADI-2 Pro.

KaiS's Website

11 Reply by RME_fan (edited by RME_fan 2022-05-21 21:53:22)

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Re: Sources that claim ADI-2 sounds better than Babyface Pro

KaiS wrote:

And yes, the cassette deck will perfectly work, connected directly to ADI-2 Pro.

It works, but not like with a preamplifier that has much higher input impedance. Well, the signal loss is very low. But in the service manual of my Technics RS-M10 cassette deck, it says that the connected input impedance should be 22 kilo-ohms more than the 1 kilo-ohm output impedance.

12 Reply by KaiS (edited by KaiS 2022-05-21 23:30:34)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

RME_fan wrote:
KaiS wrote:

And yes, the cassette deck will perfectly work, connected directly to ADI-2 Pro.

It works, but not like with a preamplifier that has much higher input impedance. Well, the signal loss is very low. But in the service manual of my Technics RS-M10 cassette deck, it says that the connected input impedance should be 22 kilo-ohms more than the 1 kilo-ohm output impedance.

No, you have a misconception about what impedance is.
It’s not level.

It will perfectly fit.

The deck has an output impedance of 1 kOhm, ADI-2 Pro has an (unbalanced) input impedance of 10 kOhm.
The resulting signal damping is 0.8 dB.

Nominal deck output is about 580 mV (Dolby Level, depends on how hot you recorded etc.).
ADI-2 has a minimal sensitivity of 1.2 V.
You end up with a healthy headroom of some 6 dB.

KaiS's Website

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Re: Sources that claim ADI-2 sounds better than Babyface Pro

KaiS wrote:

No, you have a misconception about what impedance is.
It’s not level.

It will perfectly fit.

The deck has an output impedance of 1 kOhm, ADI-2 Pro has an (unbalanced) input impedance of 10 kOhm.
The resulting signal damping is 0.8 dB.

Nominal deck output is about 580 mV (Dolby Level, depends on how hot you recorded etc.).
ADI-2 has a minimal sensitivity of 1.2 V.
You end up with a healthy headroom of some 6 dB.

Thanks for taking the time to explain this, but it's still confusing to me after reading more about impedance. Input impedance (unbalanced) for ADI-2 Pro FS R is 9 kilo-ohms in the manual. Could you tell a little more about how the signal damping was calculated, and why is input impedance of around 23 kilo-ohms often recommended in the old manuals if that doesn't matter?

14 Reply by KaiS (edited by KaiS 2022-05-27 20:02:49)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

RME_fan wrote:

[Could you tell a little more about how the signal damping was calculated, and why is input impedance of around 23 kilo-ohms often recommended in the old manuals if that doesn't matter?

You asked, so here we go smile
My above posting was a quick look approximation.
Now let’s calculate that more precisely than we practically need, just to show how that works, and what it sometimes takes to answer a simple question.


You start with looking at the Technics RS-M10 schematic:
https://elektrotanya.com/technics_rs-m1 … ad.html#dl
You see the used chip for driving the output is the NE646B Dolby B NR codec.

So look at it’s datasheet (ignore the “B”):
http://www.elektronikjk.com/elementy_cz … /NE646.pdf
On page 2 you find:
“All levels referenced to 580 mV rms (0 dB)”
This is where the DD-sign in your deck’s VU-meters should be calibrated to.
Looking at the NE646 pinout you see pin 7 is output.


In the deck’s schematic, follow the signal trace to the RCA output.

• Starting at NE646 Pin 7, you find:
• A series cap C51 25V 4.7 uF
• Switch S1-13 pin 37 - 38 linked for playback position
• A series resistor R81 470 Ohm = 0.47 kOhm
• R91 10 kOhm to ground
• The simple headphones amp around Q7 which can be approximated as R99’s 47 kOhm to ground (might be lower, depends on the unknown transformer T8 ratio and load).
• Series resistor R93 1 kOhm to output connector.
• We connect ADI-2 Pro’s input resistor of 9 kOhm to ground.

Now the Damping is to be calculated on the base of Ohms Law.

(1) ADI 9 kOhm + R93 1 kOhm = 10 kOhm (to ground).
(2) R91 10 kOhm || R99 47 kOhm = 8.25 kOhm (to ground).
(1) || (2) = 4.51 kOhm (to ground).
This is the load R81 0.47 kOhm sees, so we can calculate the 1st voltage divider’s damping (we calculate in kOhm).
0.47 kOhm into 4.51 kOhm = x 0.91 damping.
The 2nd voltage divider is R93 1 kOhm into ADI-2’s 9 kOhm.
1 kOhm into 9 kOhm = x 0.9 damping.

Now the dampings are multiplied: 0.91 x 0.9 = 0.82
We started with Dolby Level 580 mV.
580 mV x 0.82 = 476 mV = -4.2 dBu at Dolby Level on tape.

ADI-2 Pro’s lowest Reference Level is +4 dBu, so 7.8 dB headroom for peaks above tape’s Dolby Level of 200 nWb/m magnetization.
This is enough for FE and CR tapes max. saturation level.
Metal tapes can be a bit hotter, so switching to ADI-2 Pro’s next higher +13 dBu Ref. Level might be necessary if ADI-2 Pro’s analog input’s meter shows “OVR”.


According load impedance:
As you can see, the deck’s internals are already loaded with 8.5 kOhm, so it doesn’t matter if this goes down to 5 kOhm total for the chip.
The cap C51 together with the total load resistance defines the lower cutoff frequency:
4.7 uF into 5 kOhm = 6.8 Hz, no problem.


Remark:
The deck’s spec’s say output level is 420 mV into 22 kOhm.
This probably is meant with an 8 Ohms headphone connected, as the simple headphones amp Q7 - T8 does not fully decouple the load.
A typical fault of the Japanese cassette recorders of that era.
Only relevant if you plug low impedance ‘phones into this really bad sounding amp.

KaiS's Website

15 Reply by RME_fan (edited by RME_fan 2022-05-27 22:11:42)

  • From: Denmark
  • Registered: 2022-02-08
  • Posts: 18

Re: Sources that claim ADI-2 sounds better than Babyface Pro

Fascinating. In case a cassette deck needs higher input impedance, do you think the best way would be to build a 22 kilo-ohm or so resistor into the signal wire of connected RCA cables? This is much like what is done with oscilloscopes.

16 Reply by KaiS (edited by KaiS 2022-05-27 22:44:48)

  • KaiS
  • DAW Mastermind
  • Offline
  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,530

Re: Sources that claim ADI-2 sounds better than Babyface Pro

RME_fan wrote:

Fascinating. In case a cassette deck needs higher input impedance, do you think the best way would be to build a 22 kilo-ohm or so resistor into the signal wire of connected RCA cables? This is much like what is done with oscilloscopes.

Not suggested.
You get a level loss of about 10 dB.

I’ve never seen a deck that cannot drive 9 kOhm.

If really needed, the resistor must be located at ADI-2 Pro’s side, to avoid frequency response changes due to cable capacitance.


In scope probes the cable and input capacitance is compensated BTW.

KaiS's Website