Topic: ADI-2 Pro and headphones amp sound quality

I'm happily using the RME ADI-2 Pro first edition since the 2017.
The FS and R versions are quite inviting but for some random reasons I never committed the upgrade to the newest models (mainly because its DAC is still awesome...).
The only serious disappointment arrived a month ago when I tested my new Audeze LCD-X not only with my usual ADI-2 Pro built-in headphones amp, but with an external standalone headphones amp of the value of one 100th of the RME.
I realised that the ADI-2 Pro headphones amp is really powerful as advertised but not really good as expected by this kind of  mastering-grade product.
Basically, moving from a coil headphones system to the magneto-planar of the Audeze, I heard for the first time ever the extreme low end of the RME. And I was not so happy.

The low end of the RME seems to be rather not clean, maybe quite suffering of harmonic distortion, it sounds saturated and blurry compared to the external amp. The separation of the basses, on the listening, is quite difficult, even with a calibrated headphones system (Sonarworks or Acustica Audio Sienna).

The external amp is a Chinese little box with a customised opamp (Muses01) and a couple of Nichicon capacitors changed as input coupling stage.
But honestly, and astonishly, the little box outperforms the RME counterpart.

Then, please, for the next ADI2-Pro edition I warmly suggest to review and update the headphones amp circuit.
The users will be more than grateful smile
I personally work very often in movement, then having a single box doing everything at the maximum of the qulity, like it should be with this ADI-2 Pro (that I really LOVE!), would be awesome. Fortunately the external amp is very small an for now I take it with me, but, again, it would be amazing having just one single piece of hardware in my flightcase.

ps. I already discussed with a trusty owner of a later ADI-2 Pro FS R Black Edition and he confirms my impressions about the basses quality also with the new models.

Thanks.

2 (edited by ramses 2021-07-20 10:47:19)

Re: ADI-2 Pro and headphones amp sound quality

Hi LoA,

it is strange that I have not noticed this before. A few years ago I had various headphones for testing - including LCD-X and LCD-3 (Alcantara version, my current headphones) and had tested them both on the ADI-2 Pro at that time, as well as on other RME phones preamps (from UFX+ and Octamic XTC). I was extremely satisfied with the sound. Currently I am using ADI-2 Pro FS R BE.

And you are sure that you tested the same audio content at the same listening level ?? Do you know that for our ears louder sounds better ? Therefore it is very important to test at the same volume level. Otherwise this no valid test.

With which headphone preamp do you get the better results, if I may ask? I think this information should not be missing to even know what exactly you are talking about and what device you compared against the RME product. Thank you.

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

3 (edited by London Acoustics 2021-07-20 11:06:35)

Re: ADI-2 Pro and headphones amp sound quality

Hi Ramses, thanks for your very important precisations. Of course, before posting this kind of "delicate" post we made all the internal required tests.
We produce plugins and we work daily comparing even the smallest harmonic distortion variation of any audio source, in calibrated environments.
Be aware that I'm not meaning that the ADI-2 Pro map is bad, but that it can be easily improved to the current state of the tech standard... that it seems also quite cheap according with the Chinese box price.
It can be that in the 2015 the state of the art of the integrated amp was different from today. I don't know...
I think RME is clever enough to not take this post as attack but as an invite to check the headphones amp in the next ADI reissue, just like they did with the DAC a couple of time since the first edition.

FYI The box is the Douk Audio U3 Mini (Class A) with a MUSES01 OpAmp and a couple of Nichicon capacitors 10uF changed in C1 abd C9 (the input stage). But also in the standard setup with a OPA5532 and the factory surface micro capacitors sounds better in the bass section, and above (more separation, more detail, widener stage).

Sorry if I haven't post it before but I wasn't sure to be allowed to name other companies here. I'm new to the forum.

Regards.

4 (edited by KaiS 2021-07-20 11:38:38)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

The low end of the RME seems to be rather not clean, maybe quite suffering of harmonic distortion, it sounds saturated and blurry compared to the external amp. The separation of the basses, on the listening, is quite difficult, even with a calibrated headphones system (Sonarworks or Acustica Audio Sienna).

The external amp is a Chinese little box with a customised opamp (Muses01) and a couple of Nichicon capacitors changed as input coupling stage.
But honestly, and astonishly, the little box outperforms the RME counterpart.
...
Fortunately the external amp is very small an for now I take it with me, but, again, it would be amazing having just one single piece of hardware in my flightcase.

I did a lot of blind A/B of ADI-2 Pro vs other amps, often with my AUDEZE LCD-2 Revision 2 ( the model where the bass reaches down to the center of the earth):

I never heard a difference as you described.


What you hear simply is the difference from a uncompromized, DC-coupled amp the reaches down to 0 Hz (ADI-2), versus a high pass filtered amp:
Nichicon capacitors changed as input coupling stage“.

The filtering “cleans up” the bass by removing the very low frequencies.
Common practice in record studio’s mixing and mastering BTW.

Not to forget the significant amount of nonlinear distortions electrolytic caps introduce.


So what you compare is “apples to oranges” in some way.
Nothing to blame the ADI-2 for, it’s the chinese amp that is out of normal.
No distortion on RME’s amp, what goes in is what comes out, unchanged.


If you prefer this sound, you either can go on using the little amp, or try to replicate it’s sound with ADI-2’s equalizer.
Possible Starting points:
• B1 G +xx   F 20 Hz  Q 0.7 HPF
• B1 G -12   F 20 Hz  Q 0.7 LowShelving
The latter is less intrusive.


When A/B-ing, remember, the slightest difference in loudness let’s you prefer the louder amp.

5 (edited by ramses 2021-07-20 11:33:41)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

Sorry if I haven't post it before but I wasn't sure to be allowed to name other companies here. I'm new to the forum.

Ah ok, very forward thinking. But here we are talking about a comparison and we would have to talk about what was compared with what.

I can contribute nothing further to this and leave my comments as they are for now. Maybe the one or other would like to write something about it.

For the time being, I am in a comfort zone and see no need for action for me personally, a device with cinch connectors without any digital interface to connect to my main interface is for me completely out of scope.

But wait .. maybe one more comment from my side .. maybe it makes sense to you and others .. personal assumption ...

As the device has neither a digital input nor an USB interface you have three conversions ... D/A on the device that feeds this unit and then A/D (on it's cinch inputs) and  D/A on the phones output.

I can only assume that this devices simply colorizes the sound in a way that it is more comfortably for your ears and matches your personal listening habits and those of the other guy.

Believe me, if with the RME device something would be bad or not justify the price, then many more people would give such or a similar feedback....

And as I know how well the RME phones preamps are already in the usual recording products it would be a too big occasion, that just in this segment something would be missing in terms of quality and what not...

So I can only assume that this is simply your personal impression much biased based on your ears and listening habits, but nothing that you could generalize like you do, that RME has somewhere a gap or would need to do smth better.

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

6 (edited by London Acoustics 2021-07-20 11:44:25)

Re: ADI-2 Pro and headphones amp sound quality

ramses wrote:

For the time being, I am in a comfort zone and see no need for action for me personally, a device with cinch connectors without any digital interface to connect to my main interface is for me completely out of scope.

It's an analog amp, RCA IN and HP Jack out. No other digital stages. It's quite clear, transparent and totally linear (we analised it).

But it's not about that precise box, even comparing it with a similar product, maybe more known and esteemed like a Lake People G103 I can conirm my same opinion.

I was in my comfort zone too since the 2017, but once you realise the difference... unfortunately the pro-audio and audiophile environment works in this way.

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

It's quite clear, transparent and totally linear (we analised it).

Did you measure the lower limiting frequency with the headphones connected?

Re: ADI-2 Pro and headphones amp sound quality

I have 2 questions for London acoustics: 1: Do you work for a chinese company? 2: How does one "analise" a headphone amp? Im so tired of these bogus advertising ad/posts. You can hardly trust a review any longer.

ADI-2 DAC, ADI-2 PRO, DigifaceUSB, UCXII, ARC, HEGEL.h80, KEF.ls50, HD650, ie400pro _,.\''/.,_

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:
London Acoustics wrote:

It's quite clear, transparent and totally linear (we analised it).

Did you measure the lower limiting frequency with the headphones connected?

Without and with a custom box with variable impedance control (20ohm If I well remember, in this case) that we use to measure and sample also other hardware. I feel not so confident using a £1k pair of HP for the measurement...
But the question is not about the frequency response that is obviously extremely linear in both of the machines, I'm talking of a kind of "blurriness", maybe THD related to the extra bass frequencies, that doesn't convince me 100%, for this reason, as a loving customer, I'm asking RME to check.

Re: ADI-2 Pro and headphones amp sound quality

Happy_amateur wrote:

I have 2 questions for London acoustics: 1: Do you work for a chinese company? 2: How does one "analise" a headphone amp? Im so tired of these bogus advertising ad/posts. You can hardly trust a review any longer.

Sorry but I feel your post is not relevant with my topic, you are assuming wrong tone and positions to me.
English based.
My own company.
This is not a review, I'm not selling anything, I'm just trying to ask to possibly improve a section of the project of a tool I'm using on daily basis. A ADI is not only matter of DACs, and I hope it's a continuosly ongoing project (as I saw with the past FS and FS R revisions).

11 (edited by London Acoustics 2021-07-20 16:41:06)

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:

I did a lot of blind A/B of ADI-2 Pro vs other amps, often with my AUDEZE LCD-2 Revision 2 ( the model where the bass reaches down to the center of the earth):

I never heard a difference as you described.


What you hear simply is the difference from a uncompromized, DC-coupled amp the reaches down to 0 Hz (ADI-2), versus a high pass filtered amp:
Nichicon capacitors changed as input coupling stage“.

The filtering “cleans up” the bass by removing the very low frequencies.
Common practice in record studio’s mixing and mastering BTW.

Not to forget the significant amount of nonlinear distortions electrolytic caps introduce.


So what you compare is “apples to oranges” in some way.
Nothing to blame the ADI-2 for, it’s the chinese amp that is out of normal.
No distortion on RME’s amp, what goes in is what comes out, unchanged.


If you prefer this sound, you either can go on using the little amp, or try to replicate it’s sound with ADI-2’s equalizer.
Possible Starting points:
• B1 G +xx   F 20 Hz  Q 0.7 HPF
• B1 G -12   F 20 Hz  Q 0.7 LowShelving
The latter is less intrusive.


When A/B-ing, remember, the slightest difference in loudness let’s you prefer the louder amp.

I know well the effect of the capacitors (and the rest), and for this reason I changed them, just for mere listening pleasure (it's not always matter of mastering and measuring... sometimes someone like just listen to the music).
Ok, forget the modified Chinese box and also the original same box (I have both on my desk).
Try with a dedicated HP amp like the forementioned Lake People, or a Topping or even a Fiio, and compare their bass sharpness and precision with the ADI-2 Pro, with an Audeze LCD or a HiFiMan Sundara, or good coil like the top catalog from Sennheiser, calibrated to the Harman target.
There is a big difference. How not hearing that?!
Not speaking about frequency, but about revealing, of transients in the lower register (it's always difficult to describe with words...)

I'm speaking to a forum of high audio lovers or a RME lovers? Because the fisrt ones go straight to try and then report/discuss, the second ones stay in their positions for faith, forever... just to know... in the second case I will go to write directly to the RME guys.
I thought that discussing with expert in a forum was the best way.

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

I'm speaking to a forum of high audio lovers or a RME lovers? Because the fisrt ones go straight to try and then report/discuss, the second ones stay in their positions for faith, forever... just to know... in the second case I will go to write directly to the RME guys.
I thought that discussing with expert in a forum was the best way.

This is a forum mostly comprised of puritans who think:

- RME is perfect beyond reproach
- The product cannot be improved
- No accessory to that which comes with the unit can possibly make a difference
- Anyone who suggests otherwise is an idiot
- Subjectivity is unthinkable

This is perpetuated by a handful of fanboys that post prolifically and are enforced by the admins. It makes discussions very difficult, a shame because it's a great product and a forum is a good idea.

I've had a thread locked for having the temerity to suggest that different USB cables sound different, another post deleted a few days ago with no explanation.

Where in London are you? I have a ADI-2-DAC FS (manufactured late 2020) if you wanted to compare the headphone outputs.

Re: ADI-2 Pro and headphones amp sound quality

I’m not an RME-aficionado and have a lot of other systems to choose from.

The problem you describe is unknown here.
Such a huge difference in sound points to something setup wrong, or broken.


Are you aware that, when plugging the headphones, you can have a totally different setting of DSP effects than on Line out, when the ‘phones are unplugged?
ADI-2 is aware you plug the ‘phones and keeps and automatically switches different settings.

Have a look through ALL DSP functions under VOL (Balance?), I/O and EQ, with and without the ‘phones plugged in.



If this doesn’t help:

As you seem to be able to do measurements and possibly have some knowledge about electronics, I suggest to do just that.

Put the ADI-2 on the test-bench and run the standard tests:
• Frequency response.
• Nonlinear distortions at various frequencies and levels.
• Max output power on various loads and frequencies.

The target values are well documented in the manual.


An amp that sounds that bad has a real problem, this is not the faint difference you usually find with solid state amps of sufficient power.



According caps:
ALL caps distort, more or less.
Electrolytics are by far the worst, specially coupling caps on the bass!
No matter if Nichicon, Blackgates, Mundorf or just standard.
And no two specimen are the same.
They have no place in the audio signal path.

Re: ADI-2 Pro and headphones amp sound quality

mediummanting wrote:
London Acoustics wrote:

I'm speaking to a forum of high audio lovers or a RME lovers? Because the fisrt ones go straight to try and then report/discuss, the second ones stay in their positions for faith, forever... just to know... in the second case I will go to write directly to the RME guys.
I thought that discussing with expert in a forum was the best way.

This is a forum mostly comprised of puritans who think:

- RME is perfect beyond reproach
- The product cannot be improved
- No accessory to that which comes with the unit can possibly make a difference
- Anyone who suggests otherwise is an idiot
- Subjectivity is unthinkable

This is perpetuated by a handful of fanboys that post prolifically and are enforced by the admins. It makes discussions very difficult, a shame because it's a great product and a forum is a good idea.

I've had a thread locked for having the temerity to suggest that different USB cables sound different, another post deleted a few days ago with no explanation.

Where in London are you? I have a ADI-2-DAC FS (manufactured late 2020) if you wanted to compare the headphone outputs.

Produce your testing data here regarding problem.  Listening comments are not data…

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:

I’m not an RME-aficionado and have a lot of other systems to choose from.

The problem you describe is unknown here.
Such a huge difference in sound points to something setup wrong, or broken.


Are you aware that, when plugging the headphones, you can have a totally different setting of DSP effects than on Line out, when the ‘phones are unplugged?
ADI-2 is aware you plug the ‘phones and keeps and automatically switches different settings.

Have a look through ALL DSP functions under VOL (Balance?), I/O and EQ, with and without the ‘phones plugged in.



If this doesn’t help:

As you seem to be able to do measurements and possibly have some knowledge about electronics, I suggest to do just that.

Put the ADI-2 on the test-bench and run the standard tests:
• Frequency response.
• Nonlinear distortions at various frequencies and levels.
• Max output power on various loads and frequencies.

The target values are well documented in the manual.


An amp that sounds that bad has a real problem, this is not the faint difference you usually find with solid state amps of sufficient power.



According caps:
ALL caps distort, more or less.
Electrolytics are by far the worst, specially coupling caps on the bass!
No matter if Nichicon, Blackgates, Mundorf or just standard.
And no two specimen are the same.
They have no place in the audio signal path.

Well said,  entire comment.

16 (edited by CrispyChips 2021-07-20 21:02:00)

Re: ADI-2 Pro and headphones amp sound quality

Quote: “I can only assume that this is simply your personal impression much biased based on your ears and listening habits”


I found myself strongly identifying with Ramses comments, which are especially relevant when we reflect that Mr. London Acoustic's produces audio processing plug ins.

The ubiquitous plug in market is totally saturated with supposedly "audio enhancing" products, many of which augment, extend, amplify and colour particular characteristics of the audio they are designed to process.

We know that every singular individual has within their brains a personal data bank of sonically related information built over time; wholly shaped and dependent upon our specific exposure to sound sources and the acoustical environments in which they are performed.

It would seem entirely logical and to be expected therefore, that someone continuously listening to deeply coloured, processed sound, could ultimately become seduced and captivatingly enamoured by such extremes. Subsequently finding any device that delivered such a coloured performance, particularly satisfying.

In such circumstance, equipment which is "transparent" by design, will undoubtedly appear disappointingly “flat”, or lacking by comparison, though altogether far more accurately representative. To me, Ramses comments make perfect sense and provide the optimal answer.


Quote: “The box is the Douk Audio U3 Mini (Class A)”


When I purchase from Amazon, I normally look at the user reviews with considerable scepticism, but none the less read to obtain additional information, that may helpfully inform my purchase choices.

I have a rule that unless a minimum of 80% have heartily approved of a product, that I avoid purchasing it. In the case of this specific product, 29% gave it a 1 star score, with scathing remarks regarding its build quality and the accuracy of its volume knob in particular. (Knobs are very important).

Consumers subconsciously derive clues about the internal quality of a products components (or it’s lack) from visual and audible clues they pick up upon from the exterior of the product. These sometimes cosmetic indicators, facilitate logical judgements regarding the actual level of care and attention taken in regard to a products manufacturing build quality.

In this regard, tactile sensory information, is extremely important and telling where knobs are concerned.

I could write reams and reams on this subject which is a special area of expertise, but cannot at the moment.

Suffice to state, in such regards, the product you acclaim, does very badly.


Quote: “1: Do you work for a chinese company? 2: How does one "analise" a headphone amp? Im so tired of these bogus advertising ad/posts. You can hardly trust a review any longer.”

Quote: “I feel your post is not relevant with my topic.”


I live in a place where we train future leaders of nations, for top global level, adversarial debate.

Whenever a question asked is met with a degree of subtle avoidance, we understandably suspect a profound vulnerability, on the side of the avoider.

Mr. Happy_Amateurs reflections regarding bogus advertisements and post's, echo a sentiment I have held for some time regarding a great many attacks that have been launched on this site without foundation. People finding fault over nothing whatever valid at all.

They vary, but initially most are beguilingly subtle, and of course people do genuinely have problems that need to be addressed. How to deal with this growing phenomenon of deceit, as it’s not always clear what is going on and can be very difficult to sift the wheat from the chaff, for the overwhelming majority of entirely innocent posters?

To me, I think it’s entirely reasonable for forum members who feel strongly enough to respond, to directly challenge the conjectures, postulations and presuppositions that underlay any posts that are equivocally, open to question. With respect, most especially so, when a questionable post comes from an entirely new source. A singularly hallmark characteristic of such suspect posts.



Quote: “This is a forum mostly comprised of puritans who think:
- RME is perfect beyond reproach
- The product cannot be improved
- No accessory to that which comes with the unit can possibly make a difference
- Anyone who suggests otherwise is an idiot
- Subjectivity is unthinkable”


You make your points well.

They are entirely wrong, but I congratulate you for opining in a such clearly expressed way.

This is a technical support forum for consumers of RME products that require authoritative assistance.

It’s not a discussion forum for subjects that are passionately subjective or the general act of confabulating per say.

The moderators tolerate a degree of disputation and exercise an element of latitude towards excursus with particular topics.

RME is trumpeted at the top, so it’s important to appreciate that this, unlike many other audio forums, is not, simply a good hang for audio fans.

A further complication is that wide differences in the competence of users exist and further, that recording professionals rub shoulders with Hi-Fi enthusiasts.

Therefore, it’s possible to have genuinely perspicacious sympathy for any discombobulating experience that may have been constructive in formulating your deeply negative views.

The reality is entirely different from your expectation, is the salient implication to appreciate.

That happens in life with quite a lot of things experience reveals!

I wish all of you, only the very best!

17 (edited by ning 2021-07-20 21:14:56)

Re: ADI-2 Pro and headphones amp sound quality

The headphone amp circuit is the best RME could achieved given the budget / space / power consumption limits.
Various first / third party benchmarks show it's near perfect.
It's (almost) as good as delivering the full potential of what the DAC chip can achieve.

Yes, Given more space and higher budget maybe RME could achieve better, such as
- having an extra linear regulation stage after the flyback power supply, (currently they are powered directly by the flyback converter)
- duplicate the DC detection circuit to cover each channel independently (currently L and R are summed before the detection stage)
- make the feedback route back to the previous 1602 rather than the first 1688 for the composite topology. (as the gain op amp [1602] has better linearity and noise performance)
etc.

But those things not only require a bigger space / higher cost / increased power consumption,
but the improvements may be so tiny that they don't really affect the result (as DAC noise is the limiting factor).

18 (edited by KaiS 2021-07-21 06:41:23)

Re: ADI-2 Pro and headphones amp sound quality

yuhasz01 wrote:
mediummanting wrote:
London Acoustics wrote:

I'm speaking to a forum of high audio lovers or a RME lovers? Because the fisrt ones go straight to try and then report/discuss, the second ones stay in their positions for faith, forever... just to know... in the second case I will go to write directly to the RME guys.
I thought that discussing with expert in a forum was the best way.

This is a forum mostly comprised of puritans who think:

- RME is perfect beyond reproach
- The product cannot be improved
- No accessory to that which comes with the unit can possibly make a difference
- Anyone who suggests otherwise is an idiot
- Subjectivity is unthinkable

Where in London are you? I have a ADI-2-DAC FS (manufactured late 2020) if you wanted to compare the headphone outputs.

Produce your testing data here regarding problem.  Listening comments are not data…

Listening tests can indeed be executed in a scientific way, excluding prejustice.
A single person can do that, without a complicated, expensive setup.


All you need is:

• A fitting A/B box and cables that visually look the same for both devices under test.

• An AC voltmeter with a 200 or 400 mV range and 4 digit resolution to setup equal loudness, adjust both devices under test to exactly same loudness, by playing a sinewave, measuring with the load connected.

• Plug both amps, DAC’s or whatever into the A/B box without looking which is A or B and you have a perfect blind A/B comparison.

• Listen, compare, take notes for each run- through, then identify the devices.
Randomly replug the cables for the next run.
Can you repeatedly identify A or B, particular sound characteristics, with a statistically relevant hit rate?
Then you found something.

Switchbox (example):
https://smile.amazon.de/Tragbar-Audio-U … amp;sr=8-8

Cables (example):
https://smile.amazon.de/deleyCON-Klinke … 3&th=1

Multimeter (example):
https://smile.amazon.de/AstroAI-Multime … amp;sr=8-7

19

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:

Listening tests can indeed be executed in a scientific way, excluding prejustice.
A single person can do that, without a complicated, expensive setup.

• An AC voltmeter with a 200 or 400 mV range and 4 digit resolution to setup equal loudness, adjust both devices under test to exactly same loudness, by playing a sinewave, measuring with the load connected.

It's little things like this that invalidate tests and mislead people who try to do it right. Thanks for giving a list that includes this point. It requires to measure the voltage on an additional splitting point or (if possible) on opened connectors, or on accessible contact points within the AB box. That's why it usually is not done the correct way. Load impedances can easily cause 0.x dB level difference and up.

Regards
Matthias Carstens
RME

Re: ADI-2 Pro and headphones amp sound quality

ning wrote:

The headphone amp circuit is the best RME could achieved given the budget / space / power consumption limits.
Various first / third party benchmarks show it's near perfect.
It's (almost) as good as delivering the full potential of what the DAC chip can achieve.

Yes, Given more space and higher budget maybe RME could achieve better, such as
- having an extra linear regulation stage after the flyback power supply, (currently they are powered directly by the flyback converter)
- duplicate the DC detection circuit to cover each channel independently (currently L and R are summed before the detection stage)
- make the feedback route back to the previous 1602 rather than the first 1688 for the composite topology. (as the gain op amp [1602] has better linearity and noise performance)
etc.

But those things not only require a bigger space / higher cost / increased power consumption,
but the improvements may be so tiny that they don't really affect the result (as DAC noise is the limiting factor).

For this reason I listed only cheap HP amps, has no sense and it's not fair to compare i.e. the ADI-2 Pro HP amp with an Audio-GD  hardware.
What I mean is that there is now a margin of improvement in that area IMO, without raise the price and the complexity.

21 (edited by ning 2021-07-21 08:21:11)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

For this reason I listed only cheap HP amps, has no sense and it's not fair to compare i.e. the ADI-2 Pro HP amp with an Audio-GD  hardware.
What I mean is that there is now a margin of improvement in that area IMO, without raise the price and the complexity.

There's no way your cheap HP amp / expensive audio-gd can outperform the hp amp of adi-2, unless the latter is broken. Period.
No, most points I listed cannot be done without extra space.
- extra linear regulation stage takes a lot of space for cooling.
- ADI-2 is already very packed with components so no space to add another DC detection circuit.
- feedback to 1602 may be possible but I doubt how much improvement it could make, given it's already reaching the dac output spec.

Re: ADI-2 Pro and headphones amp sound quality

I will continue writing directly to the RME tech guys, thanks everyone for your opinions/feedbacks. Some useful and interesting, some close to personal attack, assuming my professional and listening skills below the average.
I preferred not to write in a open forum like Audio Science Review i.e. , just for the reason to try not give the idea of bad opinions to people that don't own the specific product. And also because I thought that RME were more present here with official replies and feedbacks. But I was wrong. RME is more prent there.
I just wish to talk directly with the RME guys about the possibility to make the HP amp stage slightly better in the sub & bass area. I will try then with mailing.
That's all, because I don't take an hardware, however exceptional,  like a untouchable monument to gaze & adore, but because it's a tools I use for business and I point always to the improvement.

Re: ADI-2 Pro and headphones amp sound quality

ning wrote:
London Acoustics wrote:

For this reason I listed only cheap HP amps, has no sense and it's not fair to compare i.e. the ADI-2 Pro HP amp with an Audio-GD  hardware.
What I mean is that there is now a margin of improvement in that area IMO, without raise the price and the complexity.

There's no way your cheap HP amp / expensive audio-gd can outperform the hp amp of adi-2, unless the latter is broken. Period.

It's matter of critycal listening, the statement of "There's no way your cheap HP amp / expensive audio-gd can outperform the hp amp of adi-2" it's a clear sign that some further training is required. Sorry.
The Audio GD Master 19 is currently one of the world's benchmarks for the HP amplification.

24 (edited by ning 2021-07-21 08:36:00)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

It's matter of critycal listening, the statement of "There's no way your cheap HP amp / expensive audio-gd can outperform the hp amp of adi-2" it's a clear sign that some further training is required. Sorry.
The Audio GD Master 19 is currently one of the world's benchmarks for the HP amplification.

okey. then this forum is certainly not for you.

everyone here knows audiogd is just scam.

this is an rme forum. if you have suggestions and ideas to improve RME products, you can list them and I believe RME is more than willing to hear about them. I see very little of such in your posts.

Re: ADI-2 Pro and headphones amp sound quality

ning wrote:

this is an rme forum. if you have suggestions and ideas to improve RME products, you can list them and I believe RME is more than willing to hear about them. I see very little of such in your posts.

To review and possibly improve the HP amp within the limits of the original design boundaries. Thanks.

Re: ADI-2 Pro and headphones amp sound quality

A company with no address, no email, what is that mean?

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

Re: ADI-2 Pro and headphones amp sound quality

Johannes AU wrote:

A company with no address, no email, what is that mean?

Is this inherent to the topic? Will it change the equation? Does an opinion weight more if the user is accepted by the community or not?

BTW in the store there is averything needed,FYI. Also we respond ususally fast to the ticket with a signature. But this has nothing to do with the topic, if not an attempt to discredit a person and his opinion.
I can be easily a passionate, very competent, with decades of exeprience for hobby and make the ecological operator (with all my respects with that job) work during the day. Will this undervalue my report?

Jeez, waht a forum...

Ok, stop this thread, please.
RME is the best, you own the best hardware in the history, with the best HP amp, your purchase is safe for the next 100 yers (y)
Bye.

One day some one other will realise that the HP amp of the ADI -2 Pro is less revealing than believed, for mixing and mastering.
I don't know if it's because the class of the amp, or the needs of keeping the size and price in a certain range, or because to rech that output power there are more stage in series, I really don't know, what I know is that here it's impossible to discover it. And even discuss in general.
See ya.

28 (edited by CrispyChips 2021-07-21 13:10:16)

Re: ADI-2 Pro and headphones amp sound quality

Quote: “company with no address, no email, what is that mean?”


Thank you for this fact which had not gone unnoticed but I chose not to raise.

This is a general point and not directed specifically at anyone in particular, as historically the audio world has many excellent businesses, that started out as small, in home, cottage industries. 

@ JohannesAU, whenever I am considering purchasing from a company, one of my first actions is to verify their location, find out a little about the people behind the company and most especially, establish the address of the premises they operate out of.

I do this because it has often been my experience that the more strikingly impressive the website of a company is, the less well established they generally are, and their premises (or their complete lack of business premises) can be an outward reflection, of the true nature and condition of a company.

So, I take to Google Earth, look over their premises, and the calibre of the general area they operate out of, as best I can and it gives me an impression of who I am actually dealing with, before I purchase from them. After sales service and support is important, and to spend hard earnt money, subsequently have a problem and afterward not even have an address for the company involved, is to me a huge red flag and a solid reason not to purchase from a particular business.

Many will argue that contact information on a website fulfils all that might be required for their business purposes. I see it as a clear sign of avoidance. Complex biological creatures and even simple biological creatures, have to move forward in the world. That’s the case for any creature that is mobile and goes all the way down to one cell organisms. The idea of approach and avoidance is a very old biologically observed principal and seems to apply across multiple levels of analysis in the animal kingdom. Why not give an address? Avoidance? 

This view will not be shared by everyone and will seem unfair to some small businesses, but time and time again it has proven to be an entirely sensible safety measure.

Always check out who you are buying from, before you buy from them.

Every time I hadn’t done this, I came to regret it!


Quote: “Listening tests can indeed be executed in a scientific way, excluding prejustice. A single person can do that, without a complicated, expensive setup.”


That’s great to know!

@ KaiS, I note from other of your posts, the nature of your most interesting job.

I wondered if you ever utilise an Anechoic Chamber for your tests and if so, for long periods, find the experience somewhat discombobulating, as so many of my pals have?

Although I am now retired, the excellent companies with whom I am connected have four Full Anechoic Chamber’s and lots more Hemi Anechoic Chamber’s along with a number of highly specialised Chambers of many varying types, to solve very specific problems and issues.

A while back, we hired the Benefield Anechoic Facility (BAF) at the southwest side of Edwards Air Force Base, the world's largest anechoic chamber, to validate three particular products effectiveness in resisting electro-magnet interference. Our own Chambers have been good enough to enable us to sort out most issues we experience and certainly the early telemetry reception problems some F1 Teams suffered from, as a favour to them. But continuing advancement of new technologies, mean such Chambers will become more and more important.

https://www.thedrive.com/the-war-zone/1 … ic-chamber


Thank you Kais, (and others) for your many fine posts which are always interesting and informative.

Re: ADI-2 Pro and headphones amp sound quality

CrispyChips wrote:

@ JohannesAU, whenever I am considering purchasing from a company, one of my first actions is to verify their location, .......

https://www.thedrive.com/the-war-zone/1 … ic-chamber


Thank you CrispyChips, at first I want to write an advice that there could be a problem on the RME hardware itself, like someone said, it was broken, or could be the problem is at the headphone, the best way is to bring it to the local service centre to check it, so I guess if London A is in England, but nothing found ....


And thank you for the link, it is awesome !

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

Re: ADI-2 Pro and headphones amp sound quality

Just a quick observation. I have an ADI-2-DAC FS for just one week now but I have considerable listening experience as a concertgoer (classical music) for more than 50 years now. My 'trick' is this: every couple of years I go to an audiologist to get an audiogram for both my ears. This I use for (nearly) perfect equalising.

That said, while fiddling* I almost panicked hearing the same distortion as described by the OP. However, this awful distortion quickly went away by repeatedly plugging headphones in and out. So, I think this phenomenon is just an accidental software glitch and we don't have to worry. Also, I never experienced this problem again.


* Equalising took quite some time and effort due to the convoluted way it is implemented in the ADI-2-DAC FS.

Re: ADI-2 Pro and headphones amp sound quality

CrispyChips wrote:

Quote: “Listening tests can indeed be executed in a scientific way, excluding prejustice. A single person can do that, without a complicated, expensive setup.”


That’s great to know!

@ KaiS, I note from other of your posts, the nature of your most interesting job.

I wondered if you ever utilise an Anechoic Chamber for your tests and if so, for long periods, find the experience somewhat discombobulating, as so many of my pals have?

Anechoic Chamber is a nice to have, and for some type of acoustics work indispensable.

For most measurements there are ways to exclude room reflections, very efficient e.g. is TDS, Time Delay Spectrometry, where a narrow band filter runs along a sine sweep.

Today I’m more (but not totally) into headphones, any quiet room can do with those.

Currently I’m out for a studio acoustics job.
This is exactly what you asked for: room and speakers are linked together for the end result.

32 (edited by KaiS 2021-07-21 15:52:15)

Re: ADI-2 Pro and headphones amp sound quality

jgysenbergs wrote:

Just a quick observation. I have an ADI-2-DAC ... while fiddling* I almost panicked hearing the same distortion as described by the OP. However, this awful distortion quickly went away by repeatedly plugging headphones in and out. So, I think this phenomenon is just an accidental software glitch and we don't have to worry. Also, I never experienced this problem again.

This is important information and underlines my initial thought:
Something is broken someway.

If London Acoustics’ unit still shows the problem he should send it in and RME should examine where’s the problem.


A possible reason could be bad ground (TRS sleeve) connection.
The resulting sound would be a diffuse, overly spread stereo image or, if no sleeve connection is happening, out-of-phase monophonic signal on both cups.
Happened here sometimes inside 3.5 to 6.5 mm adapters.

Wiping the plug can help.

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:

Something is broken someway.

If London Acoustics’ unit still shows the problem he should send it in and RME should examine where’s the problem.

this is my thought as well ---

ning wrote:

There's no way your cheap HP amp / expensive audio-gd can outperform the hp amp of adi-2, unless the latter is broken. Period.

Since the device OP has is a Pro, the easiest thing he could do is to loopback to analog in and quickly test the frequency response, preferably with a dummy load.

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:

A possible reason could be bad ground (TRS sleeve) connection.
The resulting sound would be a diffuse, overly spread stereo image or, if no sleeve connection is happening, out-of-phase monophonic signal on both cups.
Happened here sometimes inside 3.5 to 6.5 mm adapters.

Wiping the plug can help.

Especially at high humidity and sudden temperature change, it is about dew point. Here in Hongkong, after a thunderstom, when we back home and switch on the air-con, some interconnect might fail, have to unplug it and put it back after a wipe with dry cloth or with alcohol.

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

35 (edited by CrispyChips 2021-07-25 18:23:39)

Re: ADI-2 Pro and headphones amp sound quality

Quote: “every couple of years I go to an audiologist to get an audiogram for both my ears.”


I sometimes wonder whether those quick to find fault, putting audio hardware on the test bench, would do themselves and everyone else a great favour, if they put themselves on the test bench, and had their hearing tested, instead.

It’s surprising how bad the hearing of many professionals in the music industry, those involved in producing, recording engineering, live sound as well as some musicians actually is. Many have significant gaps where their hearing has been damaged by ill-advised exposure.

What’s even more surprising, is that often, they none the less remain highly capable of excellent work. I will spare you the theorising of how that is accomplished but note that in Massachusetts; scientists believe they are paving the way for the possibility that eventually, successful therapies may be developed that result in entirely restoring damaged hearing.

They have already achieved that with particular creatures successfully.


Quote: ”Anechoic Chamber is a nice to have, and for some type of acoustics work indispensable."


Yes, my reason for posting the link to BAF was to underline the essential importance to manufacturers of measurement and testing.

Individuals to whom such testing appears an anathema would do well to reflect, manufacturers are obliged to expend great efforts ensuring their products comply with current legislation, not the least of which is safety related, and which can inconveniently vary, from country to country.

Comparison charts and technical specifications widely utilised for purposes of comparison, focus upon specific areas of performance felt to be of fundamental interest to consumers. Supplying every performance parameter would overwhelm most users, who prefer simple, clear, answers to life complexities and would fail to appreciate the expended effort.


Yet there are many aspects to class leading product design that it remains an impossibility to detail on a chart or graph.

Details that one instinctively senses, feels, understands and appreciates, but which cannot be easily explained with words, and for which, no charts or graphs exist.

By using those products, be it listening, looking, touching, feeling etc. we experience the subtle qualities that actively contribute to their distinctive stature and finer calibre.

The more experience we have, the better placed to judge equipment we are evaluating. So for me, people such as yourself that see “both sides of the coin” so to speak, and can fully appreciate both those aspects commonly measured and those that cannot be, are very important.


Quote: “if London A is in England, but nothing found ...."


Location is important.

I was interested to observe that RME headquarters in Bavaria, is located in an industrial building, in a good area.

A well-designed, modern building in a pleasant setting, a good size for small product research and development, adjacent to widespread open fields, directly behind the building.

As you may be aware, microphone location and placement is fundamental to the quality of a recording. Sometimes mics are located in the ever critical “near field”, (often to avoid spill from other sound sources).

Contra wise, at times mics are located in the “far field”, where the environment in which the recording takes place, enjoys a rather greater role. If you utilise the link below, you may find the audible comparisons between near field and far field located mics, informative.


http://www1.icsi.berkeley.edu/Speech/mr/nearfar.html


You will note that whether testing equipment and recording with mics in the near field or far field, the location of the RME headquarters places them in an ideal position to utilise either field to good effect.

Most especially so, with such a good choice of fields, readily available, behind the building.


Quote: “A possible reason could be bad ground (TRS sleeve) connection.” - “Wiping the plug can help.”

Quote: “high humidity and sudden temperature change, it is about dew point. Here in Hongkong, after a thunderstom, when we back home and switch on the air-con, some interconnect might fail, have to unplug it and put it back after a wipe with dry cloth or with alcohol.”


It may be entirely coincidental, but I find it interesting that the original post was raised, precisely at the start of a recent dramatic heatwave that was acutely focussed upon London quite intensely, at that time.

In major recording studios, it was common practice for ¼” jack plugs and sockets, patch bays etc. to be regularly cleaned, often with a special product ideal for the task, to ensure perfect connectivity, via all such connections.

Although I hadn’t thought about it prior this thread. I do myself actually clean all such jacks etc. routinely, usually without even thinking about it, just prior to using them. For me, it is an instilled, routine and discipline. Exactly as is advised above.

A studio protocol I learnt from my betters, absorbed by osmosis.

36

Re: ADI-2 Pro and headphones amp sound quality

Whoever is the guy sitting behind the name "London Acoustics", and if you so think that you've found a problem with the ADI-2 HP circuitry and believe its fixable and even easily fixable, and judging from your various responses, you look like a guy who knows electronics and measurements, so why don't you just send to RME or via the admin of this forum, your detailed process undertaken, the findings and the results you've got and help the firm and all others to get better and better products instead of seemingly trying to make a fuzz out of this .. TBH, if you truly think the ch-fi thing gives you better performance over ADI-2, just switch your gears, period! No need for a big fuzz.

37 (edited by pschelbert 2021-09-28 11:42:51)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

The external amp is a Chinese little box with a customised opamp (Muses01) and a couple of Nichicon capacitors changed as input coupling stage.
But honestly, and astonishly, the little box outperforms the RME counterpart.


Thanks.

Hi

I read on the manufacturere site of this little Chinese Box:

"Adopting original TI-NE5532 classical op amp and transistor expanding current circuit, using 1300mA large current output transistor working in class A status, with ultra-low distortion, and the sound is warm and delicate, full and mellow."

I cannot read anything about Muses01 Opamp JRC. By the way NE5532 is a desing form the 80's (Sigentics, Philips)

And yes there is no address no email no phone number of the manufacturer...

Are measurements available of this box, powersweep with various load?
If you hear a difference there is definitively a signficant difference in measurements. Just show it.

Peter

Re: ADI-2 Pro and headphones amp sound quality

Good news, after some testing it seems that the huge firmware update on 21 December has fixed this problem.
The DC ADC filter bypass option is a really cool addition, thanks RME!!!
Phase distortion along the frequency spectrum has also become almost irrelevant. Awesome for measurement purpose.

A first class company.

39 (edited by Johannes AU 2022-01-31 09:13:05)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

Good news, after some testing it seems that the huge firmware update on 21 December has fixed this problem.
The DC ADC filter bypass option is a really cool addition, thanks RME!!!
Phase distortion along the frequency spectrum has also become almost irrelevant. Awesome for measurement purpose.

A first class company.

Nothing wrong with the headphones amp circuit now? there is nothing changed.

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

Re: ADI-2 Pro and headphones amp sound quality

Johannes AU wrote:
London Acoustics wrote:

Good news, after some testing it seems that the huge firmware update on 21 December has fixed this problem.
The DC ADC filter bypass option is a really cool addition, thanks RME!!!
Phase distortion along the frequency spectrum has also become almost irrelevant. Awesome for measurement purpose.

A first class company.

Nothing wrong with the headphones amp circuit now? there is nothing changed.

the bypassable DC filter I guess

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:
Johannes AU wrote:
London Acoustics wrote:

Good news, after some testing it seems that the huge firmware update on 21 December has fixed this problem.
The DC ADC filter bypass option is a really cool addition, thanks RME!!!
Phase distortion along the frequency spectrum has also become almost irrelevant. Awesome for measurement purpose.

A first class company.

Nothing wrong with the headphones amp circuit now? there is nothing changed.

the bypassable DC filter I guess

It’s the other way around:

There was no DC filter in the firmware before.
Now there is a DC filter, plus DC Filter bypass option if someone wants to come back to the old version.

Re: ADI-2 Pro and headphones amp sound quality

KaiS wrote:
London Acoustics wrote:
Johannes AU wrote:

Nothing wrong with the headphones amp circuit now? there is nothing changed.

the bypassable DC filter I guess

It’s the other way around:

There was no DC filter in the firmware before.
Now there is a DC filter, plus DC Filter bypass option if someone wants to come back to the old version.


Yes, at 66/47 (2021 Christmas Eve) there is only a selection of the Digital DC protection on/off, DC filter option only appears at 78/48 (Jan 20. 2022).

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

43 (edited by KaiS 2022-02-01 07:51:35)

Re: ADI-2 Pro and headphones amp sound quality

Johannes AU wrote:
KaiS wrote:
London Acoustics wrote:

the bypassable DC filter I guess

It’s the other way around:

There was no DC filter in the firmware before.
Now there is a DC filter, plus DC Filter bypass option if someone wants to come back to the old version.


Yes, at 66/47 (2021 Christmas Eve) there is only a selection of the Digital DC protection on/off, DC filter option only appears at 78/48 (Jan 20. 2022).

Who cares about outdated versions, if the current firmware seems to run smooth and offers all options smile

It’s really amazing how the RME team works on perfecting their products, even adding new functionality without sacrificing existing ones.


With headphones that can reproduce sub-low frequencies AND can stand at least 5 watts of electrical power, the DC-protection could be disabled.
This is true for some, but not all AUDEZE headphones, but not many more come into my mind.

If you want the sub-lows, but still want protection from DC-accidents, set DC-Protection to “ON”.

44 (edited by pschelbert 2022-02-01 22:44:28)

Re: ADI-2 Pro and headphones amp sound quality

London Acoustics wrote:

The low end of the RME seems to be rather not clean, maybe quite suffering of harmonic distortion, it sounds saturated and blurry compared to the external amp. The separation of the basses, on the listening, is quite difficult, even with a calibrated headphones system (Sonarworks or Acustica Audio Sienna).

The external amp is a Chinese little box with a customised opamp (Muses01) and a couple of Nichicon capacitors changed as input coupling stage.
But honestly, and astonishly, the little box outperforms the RME counterpart.


Thanks.

Check the frequnecy response of the Chines box versus RME.

Most probably the chinese box just cuts off low end and the RME does reproduce full low end.

Result: your headphone cannot reproduce low end in a clean manner, hence distortion.
This is not the problem of RME but of the headphone.