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Topic: Optical input of RME

Hello fellas. Maybe you can help me understand.
I have 2 DACs, RME ADI-2/4 and Apogee Symphony Desktop (RME sounds better).

I tried to use different inputs of my RME and have different results. If someone knows why - tell me.

I compere 2 schemes:
1. Notebook (Quboz) - USB - RME - loudspeakers.
2. Notebook (Quboz) - USB - Apogee Symphony Desktop - optical s/pdif - RME - loudspeakers.

The second scheme sounds much better. Music more crisp, sound have more details, "holographic image" more precise. Why so? is it my notebook which gave some interference from processor or whatever inside it, is in a dirty power or by doing so I do not use FPGA in RME (instead singnal from s/pdif going directly to ESS chip)?

2 Reply by ramses (edited by ramses 2024-11-02 15:14:16)

  • ramses
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Re: Optical input of RME

Digital lossless transfer of audio data does not change the sound.

It does not matter whether the transfer happens via USB, ADAT, optical or coaxial SPDIF, AES, MADI, AVB or Dante. It is and stays lossless transfer of digital audio data. You can even validate it using the reference converters Bit test.

Regarding #2, can you check with ADI-2/4's Bittest, whether audio transport is still lossless?

Next and most important point. Are you aware of that
- blind tests are needed to exclude psychoacoustic effects?
- you have to compare music at the same listening level (louder sounds better)

You stated that the RME sounds better compared to the Apogee, and now you claim that the RME sounds even better when chained after the Apogee? This is not logic, isn't it?

Maybe you have to improve your testing method first for more proper and logic sounding results.

At the end of the day you do not need to spend so much work on this.

Simply validate the lossless audio chain using the reference converters Bittest.

By this you validate the lossless transfer of audio data up to the DSP of the reference converter.

From there you have D/A conversion in the same quality without any change to sound and no matter over which digital path the lossless audio data had been transferred.

Also jitter is no issue as SteadyClock FS will always dampen jitter in the best possible way even if the reference converter should not be the clock master in a setup (by design).

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 2024-11-02 17:22:30)

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Re: Optical input of RME

An Optical inter-step has the big advantage of providing “Galvanic Isolation”, a break in the metallic interlinks that transfers electrical current.
This prevents electrically transmitted noise to spread along the shields of audio lines.

ADI-2 itself is totally immune against this type of noise, but devices like power amps and their connection scheme, specifically if unbalanced, might not.
Their audio quality can suffer from noise that origins e.g. from a computer.


”Galvanic Isolation” can be achieved by USB isolators too, but you have to pick the right one:
https://forum.rme-audio.de/viewtopic.ph … 03#p223103


Jitter is of no concern at all, as it is filtered out by ADI-2 in any configuration.


Quite often small differences in volume suggest there is a major sound difference.

As Ramses mentioned, RME Bit Test (manual page 101) reveals such within seconds.
This makes sure you’re not chasing a ghost.
You should get the “Bit Test … passed” in both configurations.

Please do the test and report back.

KaiS's Website

4 Reply by Buddser (edited by Buddser 2024-11-02 21:27:00)

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Re: Optical input of RME

Checked with bit test:

1. Audirvana - all files passed (USB and optical - both identical results).
2. Native mac os Player - 48/16, 48/24, 48/32 - passed, other files failed (USB and optical - both identical results).
3. Qobuz - my main streaming player - I don't know how to load in it bit test tracks, any thoughts?

Made the listening level the same - I'm hear the difference.

About USB Isolator, ordered the same Topping a few days ago to check whether it is a ground loop or not (thank you, I'll try this one in a week or two).

PS. I don't understand the purpose of a blind tests... and don't have an opportunity to do it. Heard that they don't give a clear result.

5 Reply by KaiS (edited by KaiS 2024-11-03 00:08:09)

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Re: Optical input of RME

Buddser wrote:

PS. I don't understand the purpose of a blind tests... and don't have an opportunity to do it. Heard that they don't give a clear result.

The blind test is the only way to exclude expectation bias.
Doing it several times in a row with random presentation of the configuration-under-test gives a reliable insight of true differences.

From ancient times our brain is configured to estimate the most out of as little information as usually was available- the click of a breaking leaf in the distance: is it the bear that wants to eat you, or is it the rabbit you want to catch and eat … smile
Receptions of faint sound, combined with visuals and smell, maybe even tactile vibrations was what kept people of the stone age alive.

This mechanism stands in the way of objective judgment, and blind tests can exclude it to avoid fooling yourself making expensive wrong decisions.

If the difference is significant the result will soon be obvious, but even tiny differences can be detected by making enough A/B runs until a statistically significant result is achieved.

In sighted A/Bs you never can be sure if it’s just the idea, the looks or whatever, that you prefer, and that’s true even if you believe you detected bigger differences.

The stories I could tell about self-delusion could fill a little book.
E.g. once I set an EQ (in the studio, producing music) and out of my experience how it should sound could hear every change I did to the knobs - to finally find out it wasn’t activated, didn’t do anything - stuff like that.


Based self delusion a whole “audiophile” industry lives from selling people snake oil of all kinds, perverting the goal of objectively improving music reproduction into an elitist money making machine.

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6 Reply by KaiS (edited by KaiS 2024-11-03 00:14:03)

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Re: Optical input of RME

If bit test passes, you can be sure there‘s nothing to improve on this side.
For Qubuz player there‘s no direct way to run the test.
According to your results it can be estimated that it‘s probably OK.


Ground loop disturbances are another story.
You soon will find out with the Topping USB Isolator if there‘s an improvement.

KaiS's Website

7 Reply by Buddser (edited by Buddser 2024-11-03 06:43:14)

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Re: Optical input of RME

ok, thank you I will tell you do I hear the difference or not with this topping.

About blind test and sight test in this particular scheme.
I have my doubts about blind tests because of that:

after I percept the difference in sound, I tried to connect everything through the Apogee (thinking that the reason of this difference in sound is a USB connection itself, I was 100% sure that optical cable somehow clean the sound or you could say prevent interference from the CPU to go further in audio chain).
And whether I connect it through USB or optical (through RME - backward scheme (in a sense what I wrote in my first post)) I hear no difference at all. But if in this case think that I was sure (100%) that this is the cable - I must hear the difference... But I didn't.

I understand that our mind can play with us. I also heard this story about 3 blind tests in a raw and when always first device/sound is ok, second is meah, and the third is awesome. Managers in audio strores use it to sell more staff.
I also can say that to really hear (it is only about my ears maybe) I need some time of listening session to make a conclusion. And in this case I heard both schemes more than 2 weeks sometime switching from one to another.

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Re: Optical input of RME

Buddser wrote:

And whether I connect it through USB or optical (through RME - backward scheme (in a sense what I wrote in my first post)) I hear no difference at all. But if in this case think that I was sure (100%) that this is the cable - I must hear the difference... But I didn't.

What makes you state that?

Fireface UCX II + ARC USB > ADI-2 Pro FS R BE > Neumann KH 750 DSP + MA 1 > KH 120 A

9 Reply by KaiS (edited by KaiS 2024-11-03 07:50:34)

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Re: Optical input of RME

Buddser wrote:

ok, thank you I will tell you do I hear the difference or not with this topping.

About blind test and sight test in this particular scheme.
I have my doubts about blind tests because of that:

after I percept the difference in sound, I tried to connect everything through the Apogee (thinking that the reason of this difference in sound is a USB connection itself, I was 100% sure that optical cable somehow clean the sound or you could say prevent interference from the CPU to go further in audio chain).
And whether I connect it through USB or optical (through RME - backward scheme (in a sense what I wrote in my first post)) I hear no difference at all. But if in this case think that I was sure (100%) that this is the cable - I must hear the difference... But I didn't.

I understand that our mind can play with us. I also heard this story about 3 blind tests in a raw and when always first device/sound is ok, second is meah, and the third is awesome. Managers in audio strores use it to sell more staff.
I also can say that to really hear (it is only about my ears maybe) I need some time of listening session to make a conclusion. And in this case I heard both schemes more than 2 weeks sometime switching from one to another.

First of all:
You assumed the cable MUST make a difference, and were disappointed you couldn’t nail that.

I can tell you from my life-long experience in the studio:

Cables that are not broken and are suited for the purpose don‘t make a difference at all, neither analog nor digital.


This myth was pulled up from the few occasions where cable’s parameters are integral part of an audio transduce system.

In home-audio thats the MM vinyl pickup.
Here the cable‘s capacitance with the transducer’s coil’s inductance creates a strong resonance that typically is located in the audible range and shifts with different cables.
This of course is audible.
Without an MM vinyl pickup in the chain, e.g. on a line out, that resonance doesn‘t happen.

The MM-pickup experience started the cable discussion long ago.
As people don’t understand the circumstances, in the early ‘80s the idea was transferred to all kind of cable links, and clever marketing people jumped on that train to sell more and more rip-off priced cables to the believers.

Imagine, after buying a 2000 bucks worth of cable, who would not hear the “improvement” in a sighted (and often even positively commented) A/B?
Expectation bias at it’s best.


For digital cables it’s even more like nonsense - you did the bit test and all bits came in un-altered.
What could a “better” cable improve on that?
Anyway the bits are not transferred in the order they are handled in the DA-converter, so need to be sorted and re-clocked there.
ADI-2’s FS- (femto-second-) clock does that par excellence, much better than can be transferred even through a dedicated clock-cable at all.


Optical vs. electrical connection is another story - for the reason I explained above.


I’d say, concentrate on the points that really make a difference.
Using different DAs can, to some amount, but usually not night and day.

KaiS's Website

10 Reply by Buddser (edited by Buddser 2024-11-03 10:04:56)

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Re: Optical input of RME

unpluggged wrote:
Buddser wrote:

And whether I connect it through USB or optical (through RME - backward scheme (in a sense what I wrote in my first post)) I hear no difference at all. But if in this case think that I was sure (100%) that this is the cable - I must hear the difference... But I didn't.

What makes you state that?

Because if I was biased and all this different in sound will be in my mind only, then I would hear the difference in type of connection at every device (But I don't).

11 Reply by Buddser (edited by Buddser 2024-11-03 10:01:34)

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Re: Optical input of RME

KaiS wrote:
Buddser wrote:

ok, thank you I will tell you do I hear the difference or not with this topping.

About blind test and sight test in this particular scheme.
I have my doubts about blind tests because of that:

after I percept the difference in sound, I tried to connect everything through the Apogee (thinking that the reason of this difference in sound is a USB connection itself, I was 100% sure that optical cable somehow clean the sound or you could say prevent interference from the CPU to go further in audio chain).
And whether I connect it through USB or optical (through RME - backward scheme (in a sense what I wrote in my first post)) I hear no difference at all. But if in this case think that I was sure (100%) that this is the cable - I must hear the difference... But I didn't.

I understand that our mind can play with us. I also heard this story about 3 blind tests in a raw and when always first device/sound is ok, second is meah, and the third is awesome. Managers in audio strores use it to sell more staff.
I also can say that to really hear (it is only about my ears maybe) I need some time of listening session to make a conclusion. And in this case I heard both schemes more than 2 weeks sometime switching from one to another.

First of all:
You assumed the cable MUST make a difference, and were disappointed you couldn’t nail that.

I can tell you from my life-long experience in the studio:

Cables that are not broken and are suited for the purpose don‘t make a difference at all, neither analog nor digital.


This myth was pulled up from the few occasions where cable’s parameters are integral part of an audio transduce system.

In home-audio thats the MM vinyl pickup.
Here the cable‘s capacitance with the transducer’s coil’s inductance creates a strong resonance that typically is located in the audible range and shifts with different cables.
This of course is audible.
Without an MM vinyl pickup in the chain, e.g. on a line out, that resonance doesn‘t happen.

The MM-pickup experience started the cable discussion long ago.
As people don’t understand the circumstances, in the early ‘80s the idea was transferred to all kind of cable links, and clever marketing people jumped on that train to sell more and more rip-off priced cables to the believers.

Imagine, after buying a 2000 bucks worth of cable, who would not hear the “improvement” in a sighted (and often even positively commented) A/B?
Expectation bias at it’s best.


For digital cables it’s even more like nonsense - you did the bit test and all bits came in un-altered.
What could a “better” cable improve on that?
Anyway the bits are not transferred in the order they are handled in the DA-converter, so need to be sorted and re-clocked there.
ADI-2’s FS- (femto-second-) clock does that par excellence, much better than can be transferred even through a dedicated clock-cable at all.


Optical vs. electrical connection is another story - for the reason I explained above.


I’d say, concentrate on the points that really make a difference.
Using different DAs can, to some amount, but usually not night and day.

I think you miss a point a little bit. I said when I checked on second device the same thing, that I hear in RME, I didn't hear the difference. In that case I agree with you - the cables didn't sound different.

The second thing, I'm not in a studio, I'm using this system at home, and don't have an opportunity to create pureness of studio in a sense of sound quality. But I get it, that in a studio there are no difference in sound from different cables in digital or analog domain (maybe, I had never been in a BIG studio to realize that).

Can't say anything about vinyl, never heard it, it's like different dimension.

And again thank you for this open forum, that provide open discussion on every aspect of RME sound and everything in between.



PS. By the way. I always wondered RME ADI-2/4 PRO SE is a studio device or a home device? As I think there are different conditions for studio and home devices.

12 Reply by unpluggged (edited by unpluggged 2024-11-03 10:21:59)

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Re: Optical input of RME

Buddser wrote:

Because if I was biased and all this different in sound will be in my mind only, then I would hear the difference in type of connection at every device (But I didn't).

Another unfounded statement. It doesn't work like that, and you had been repeatedly advised on how to exclude bias as much as possible.

Cables have no sound. Properly constructed analog cables have almost no points of failure. Digital cables don't carry audio; they carry data using some form of encoding or modulation. Any fault or transmission interference severe enough to corrupt the data would lead to errors in transfer and decoding, not to subtle differences in sound. KaiS has summed this up very well.

Buddser wrote:

But I get it, that in a studio there are no difference in sound from different cables in digital or analog domain (maybe, I had never been in a BIG studio to realize that)

It does not matter where the cables are. I am also a home user and don't experience any of the problems you described.

Buddser wrote:

PS. By the way. I always wondered RME ADI-2/4 PRO SE is a studio device or a home device? As I think there are different conditions for studio and home devices

It's a professional device that is targeted at pros and enthusiasts. There are use cases for it both in audio production and in audio consumption. Again, the concepts of "home" and "studio" are incorrect and ambiguous here. I understand that it's part of that audiophile myth that states that there are "professional" audio products (that are not suitable to enjoy music) and then there are "audiophile" products (that are "musical"). This perception is totally wrong, to say it mildly.

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Re: Optical input of RME

unpluggged wrote:
Buddser wrote:

Because if I was biased and all this different in sound will be in my mind only, then I would hear the difference in type of connection at every device (But I didn't).

Another unfounded statement. It doesn't work like that, and you had been repeatedly advised on how to exclude bias as much as possible.

I'm confused and don't understand what are you propose me to do. I tried the same scheme with other device - doesn't it an attempt to exclude bias?

14 Reply by KaiS (edited by KaiS 2024-11-03 14:32:56)

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Re: Optical input of RME

Sorry, seems I derailed the discussion a little.

Studio and home use have a huge overlap, and in some areas even got closer through the years.


ADI-2/4 Pro SE has it’s place in both environments:

You can link it to a studio DAW as central unit for in-the-box working + a little analog i/o, e.g. to work on vocal or instruments overdubs, analog transfers and mastering.


Or just like me - my studio is a little smile bigger, so ADI-2/4 Pro SE has found it’s place for my private music enjoyment, fulfilling all demands I have on a separate headphones listening space.
Through a digital 8x8 matrix it even has links to my “big” system.
It’s so convenient to switch on just one device and start listening to music.

BTW: streaming is from an otherwise decommissioned iPhone.
This makes the whole config portable in a little box for travel.

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15 Reply by Kubrak (edited by Kubrak 2024-11-03 22:12:31)

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Re: Optical input of RME

I would add that even blind test is not suffitient in many cases. Only double blind test gives 100% unbiased results.

Double blind test is done in a way that neither listener, nor device operator knows which device is on. It is known only to the third subject that is not in contact with listener and operator during tests.

Double blind test avoids leaking any information concerning device, even by unconsious way, from operator to listener. None of them knows what device is on.

16 Reply by KaiS (edited by KaiS 2024-11-04 00:07:54)

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Re: Optical input of RME

Double blind is impossible to do when you‘re alone, evaluating stuff.

I just use exact same cables and blind and randomly replug for each run.
So I have no chance to know which is which.
Then take notes, afterwards reveal the identity.

Depending on how obvious the differences are, a small or large number of A/Bs is needed for a significant result.

An important part is precise level match.
I typically calibrate for few 1/100th of a dB, and check for drift once in a while.

Such an evaluation can easily take half a day to prepare and execute.
At least nothing to do in a few minutes.

If you look at the process, it comes close to double blind, as none of the participants (just me) knows which is which smile .

KaiS's Website

17 Reply by Kubrak (edited by Kubrak 2024-11-04 14:42:38)

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Re: Optical input of RME

Well, actually one may perform double blind test even in one person. For example, computer (or whatever) may randomly change the devices´ setup.

Your blindly connecting may be close to it. I just do not know, how do you get know what the random setup was in each case.

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Re: Optical input of RME

Kubrak wrote:

how do you get know what the random setup was in each case.

With a camera, make a photo after cabling or let the camera film a video during cabling or during the test.

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Re: Optical input of RME

Kubrak wrote:

Well, actually one may perform double blind test even in one person. For example, computer (or whatever) may randomly change the devices´ setup.

Your blindly connecting may be close to it. I just do not know, how do you get know what the random setup was in each case.

At the end of the day, it is important to know that psychoacoustic phenomena exist and that many of the audio myths are simply nonsense.

Performing blind tests or in the way KaiS is doing, plus the knowledge of psychoacoustic is way better compared to the usual testing and claims you hear in audio related forums.

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

20 Reply by KaiS (edited by KaiS 2024-11-04 21:16:28)

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Re: Optical input of RME

Kubrak wrote:

Well, actually one may perform double blind test even in one person. For example, computer (or whatever) may randomly change the devices´ setup.

Possible, but not very practical for an average layman.

I once participated in such a fully automated evaluation, double blind triple stimulus A/B/C, to find out at what bit rate MP3s sound transparent (identical to the original) for a majority of people.

Building up the test, hard and software, took several days.

Your blindly connecting may be close to it. I just do not know, how do you get know what the random setup was in each case.

That‘s simple: after every A/B run I have a look.

I end up with a list, in simplest case:
Preferred device X : 49 times
Preferred device Y: 51 times

In this case seems X sounds equally good as Y, if that was the question.


The question(s) are an important part of every A/B:
Do I want to detect a preference, a difference and/or what else?


In the test mentioned above the question simply was:
Which is the MP3: A, B or C.
In each run two letters contained the same original, and one was the MP3.
The assignment of course changed for every run.


Much farther went the German magazine Hifi-Stereophonie.
On a regular base, they did so called “Psychometric Speaker Tests” with a significant number of participants.
They had to answer a lot of prepared questions about the sound characteristics of a field of (typically 6) pairs of speakers that were blind A/B-ed against each other.
Then the results were statistically evaluated, with a good correlation of what I  found when auditioning those speakers in the shops.

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Re: Optical input of RME

I thought so. You get the information, what device has been used during the testing session. It still may deviate the results. But sure, it is way, way better than no blind test, or possibly even blind test when other person changes the setup.

I guess one could use Totalmix and Digiface USB to switch devices routing. And controll Totalmix using computer and MIDI.

I fully agree that to make propper test is time consuming/costly.....

By the way, what was the result of mp3 testing? Which bitrate is transparent for general folks?

22 Reply by KaiS (edited by KaiS 2024-11-04 22:57:19)

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Re: Optical input of RME

Kubrak wrote:

I By the way, what was the result of mp3 testing? Which bitrate is transparent for general folks?

At that time storage space was at a premium.

So the German national broadcaster decided to use 256 kbit/s, which the majority of test participants could not significantly distinguish from the 48 kHz 16 bit original.

The test even included some generations of “stacked” encode/decode processings, but I don’t remember the result.
Would need to find the complete report again.

Interestingly there were some people, all classical Tonmeisters, that could identify 100% of even the max. 384 kbit/s rate mp3 samples.
Probably they already knew what kind of artifacts to watch out for.

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23 Reply by MC

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Re: Optical input of RME

Definitely, and they only concentrated on these. You must still have exceptional hearing to be able to do so, at that rate.

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24 Reply by Buddser (edited by Buddser 2024-11-10 14:36:19)

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Re: Optical input of RME

Hi Everyone.

I got an USB isolator (Topping HS02).

I've compare again 2 different audio chains:

1. Notebook (Quboz) - USB (new, 10 cm cable) - Topping HS02 (new) - USB - RME ADI-2/4 PRO SE - Balanced cables - loudspeakers.
2. Notebook (Quboz) - USB - Apogee Symphony Desktop - optical s/pdif - RME ADI-2/4 PRO SE - Balanced cables - loudspeakers.

And again... The same result. The second scheme sounds better (more detailed sound, deep bass, wider scene...).
The first scheme sound a little muddy and softer with less details.

I also can say, that I have voltage stabilizer, so I have a clean energy.

Any thoughts? Where I could go next?

(Could it be some processing of a signal in Apogee that changes all this perceptible (to my ears) changes?)

25 Reply by ramses (edited by ramses 2024-11-10 14:55:21)

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Re: Optical input of RME

Still not heard about the Bit test or what's the value of the "Bit test"? Then please read about it in the manual.
You can download the test files from RME free of charge.

Perform the Bit test for both of your use cases.
If it succeeds in both cases, then audio is unaltered from the audio source up to the DSP of the ADI-2/4 Pro SE.

If you still hear differences, although the Bit test clearly shows that the digital data stream was not altered in the digital domain, then the differences can only be due to level differences (louder sounds better) or other psychoacoustic phenomena (your expectations, pre-bias).

I am not sure whether Qobuz supports playing of RME test files (WAV files).
If not, simply use another music player, like e.g. MusicBee and use the MADIface ASIO driver to exclude any issues of Windows Sound system. Take special care, that the volume of the MusicBee player is set to 100% otherwise the Bit Test will fail, as it would alter the bit pattern by such a volume reduction at the player.

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

26 Reply by Kubrak (edited by Kubrak 2024-11-10 16:46:13)

  • Kubrak
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Re: Optical input of RME

"Could it be some processing of a signal in Apogee that changes all this perceptible (to my ears) changes?"

Bit test, that Ramses suggests to do, would answer it. If the bit test passes on the both tested chains, the resulting sound must be the same. If one of the chains tested would not pass, it would indicate there is a problem (test case 1) or the chain processes/alters the stream (test case 2 - there may be DSP made on signal to "improve" it).

Generally the both cases, be it 1 or 2, should pass the bit test.

27 Reply by KaiS (edited by KaiS 2024-11-11 13:04:31)

  • KaiS
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  • Registered: 2020-02-05
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Re: Optical input of RME

Buddser wrote:

I got an USB isolator (Topping HS02).

I've compare again 2 different audio chains:

1. Notebook (Quboz) - USB (new, 10 cm cable) - Topping HS02 (new) - USB - RME ADI-2/4 PRO SE - Balanced cables - loudspeakers.
2. Notebook (Quboz) - USB - Apogee Symphony Desktop - optical s/pdif - RME ADI-2/4 PRO SE - Balanced cables - loudspeakers.

And again... The same result. The second scheme sounds better (more detailed sound, deep bass, wider scene...).
The first scheme sound a little muddy and softer with less details.

(Could it be some processing of a signal in Apogee that changes all this perceptible (to my ears) changes?)

Both configurations USB–ADI-2 and the Apogee–ADI-2 passed the RME Bit Test, you told us here:
https://forum.rme-audio.de/viewtopic.ph … 24#p226924

This 100% excludes any processings inside Apogee, and even excludes driver issues with all config's that pass the test.


Maybe you repeat Bit Test now, then only compare the sound of config's, including the player app, that pass the test.
This makes sure the difference isn’t happening in the digital domain.

On ADI-2/4 check that SRC is off for the optical input:
SETUP / SPDIF/Remap Keys / SRC: OFF

To exclude other config issues, run ADI-2/4 Pro SE in DAC- instead of Auto-Mode.
This way ADI-2 keeps the same internal configuration when switching inputs.
Still don’t forget to unplug USB when running Optical.
Optical BTW can stay plugged, it’s ignored when USB is selected as input.

SETUP / Device Mode/DSD / Basic Mode: DAC


BTW: what about the connection ADI-2 ->power amp, balanced or single ended?

KaiS's Website

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,770

Re: Optical input of RME

If there is an audible difference, it must be measurable. Try various test signals, sweeps, stereo/polarity tests etc. If you can demonstrate the vague descriptions of the differences you perceive ("more detailed", "wider") as actual measurable parameters, it will be easier to find a possible cause.  There could be some in your cabling or elsewhere that causes this. Or some kind of misconfiguration. This is not likely something that has to do with "sound quality" of different signal paths as such.

You may have something misconfigured in the setup of the ADI as an audio interface on the Mac. What's the exact MacOS version here? Can you test this with another computer?

Regards
Daniel Fuchs
RME

RME Support's Website