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Measurements of RME ADI-2 DAC and Headphone Amp

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amirm

amirm

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Would it be helpful if I post the curves here when I buy the microphone? It is good for room correction measurements. So I think it is money well spent, I hope.
A measurement microphone is a must have. For now though, I would loop back the output of the RME to its input and use a program like REW to make sure frequency response is flat and nothing is broken.
 

Bliman

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A measurement microphone is a must have. For now though, I would loop back the output of the RME to its input and use a program like REW to make sure frequency response is flat and nothing is broken.
Thank you for the reply. I would follow the advice given here.
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And put the results here (or in another thread if this is better).
I have no idea how I would loop back the output of the RME to its input.
I also have this harsh and hard treble with my headphones. Maybe the Grace Design is seriously rolled off I don't know. The Grace design with headphones on seldom gets harsh or hard.
And I also think that eq will help me a lot.
Also thanks for helping me forum.
 

JIW

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My RME goes to a Lyngdorf sda 2175 power amplifier with XLR cables. The RME is connected by RCA to the NAD c542 cd player. And the power amplifier is connected to Dynaudio 52 SE speakers and a Q acoustic subwoofer.
The level of the RME is set to 5dBu (I think it is called that) and is standard on autolevel. The Lyngdorf does need 2 Volt. Maybe that is where the problem lies. But I don't think I can set the RME lower.

As you mention using SPDIF coax, check the State Overview. SP c should show (for CD): 'sync 44.1 cons 16' and Clock Source should show 'SPDIF coax'.

Also, try using the USB connection and see if your impressions remain the same.
 

March Audio

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That is the problem. When I dialled down the treble by 6 dB I had a feeling it did very little. Could it be that the power amplifier can't deliver enough juice to the speakers?
Would it be helpful if I post the curves here when I buy the microphone? It is good for room correction measurements. So I think it is money well spent, I hope.
6dB is a lot, if this is not overtly noticeable then something is very wrong somewhere but I can't tell you what from here.

Blown a tweeter? But of course that doesn't tally with you saying it sounds bright.
 
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Tks

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Wait.. I just realized something. The new RME refresh is set to produce what, a 117db SINAD people are saying. If it does this. What is the actual limits of the amp section. Just how good is this thing really? Is this one of the rare devices like the Atom and just a few others that go toe to toe with THX tech? Nice..
 

solderdude

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Could it be that the power amplifier can't deliver enough juice to the speakers?

Nope, otherwise it would have sounded crap with your previous DAC as well.
Switch the M902 back and if it sounds good there is nothing wrong with the amp speakers.
Use the same cables to be sure.

This may come down to a defective device or operator error.
6dB treble down should be VERY audible.

You can even use a phone to make some crude recordings of the sound if the differences are that big.
 

JIW

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Wait.. I just realized something. The new RME refresh is set to produce what, a 117db SINAD people are saying. If it does this. What is the actual limits of the amp section. Just how good is this thing really? Is this one of the rare devices like the Atom and just a few others that go toe to toe with THX tech? Nice..


@MC_RME addressed this some while ago for the rev 1. Obviously, the amps in rev 2 are no worse...
I would like to clarify this a bit more because people often ask about using the Atom or THX with the ADI, seeing that those devices have partly much better specs. The Atom (and THX) are both analog devices and are measured that way. The ADI's Extreme Power stage can not be measured like that, as one always has the included DAC in the signal path. The ADI's phones output stage is much better than the values the DAC provides. If not then we would not be able to deliver the DAC's data sheet specs at the phones output.

Putting the Atom or THX behind the ADI, connected via RCA or XLR, will limit their performance to that of the DAC. In this regard the above comparison of noise between Atom and DAC might be a bit misleading. Connecting the Atom to the DAC's XLR output would not result in less noise at all. Nor would one get to see the super low THD values of the THX.

Therefore the Atom behind the ADI-2 Pro or DAC is a setup that brings no improvement at all (instead it bypasses the various protection mechanisms that the Extreme Power stage offers). The THX on the other hand has more power and offers balanced operation, which can be a valid reason to add it to a setup.
 

Tks

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@MC_RME addressed this some while ago for the rev 1. Obviously, the amps in rev 2 are no worse...

I recall this, but it doesn't answer my question though >_> I didn't ask if the amp section is good, I was wondering how good is it. Obviously we consumers can't know as there is no way of testing it in separation of the DAC.
 

JIW

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I recall this, but it doesn't answer my question though >_> I didn't ask if the amp section is good, I was wondering how good is it. Obviously we consumers can't know as there is no way of testing it in separation of the DAC.

One can do some math to extrapolate the noise level (by assuming noise from DAC and amp are uncorrelated): a 3 dB increase in noise would imply equal noise between DAC and amp, a 1 dB increase would imply about that the noise from the amp is about 6 dB lower than that of the DAC, if the amp's noise is 10 dB lower than that of the DAC, the total noise is about 0.4 dB higher and if the amp's noise is 20 dB lower than that of the DAC, the total noise is about 0.04 dB higher than the noise of the DAC.

Thus, the noise level of the amp section is likely between 10-20 dB below that of the DAC.

Distortion is a bit more difficult to calculate because it depends on the correlation between the distortion of the DAC and the amp. If one harmonic is of the same level and in phase, the harmonic in the DAC+amp output is 6 dB higher while if the levels are still the same but the relative phase is pi/180 degrees (half a cycle), the harmonic from the amp cancels that from the DAC. If the amplitudes of the harmonics are not the same, things get even more complicated.

However, the same math as that for the noise level can still be done assuming all relative phases are equally probable, i.e. the harmonics can be treated as uncorrelated in expectation. Thus, the distortion of the amp section is expected to be 10-20 dB below that of the DAC.

Anyways, maybe @MC_RME could drop some ball park numbers for the amp sections.
 
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Nango

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Is anyone aware of a good "black friday" offer in EU for even the old version of this ADI-2 ......... preferably below 700€ ??????
 

VintageFlanker

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Is anyone aware of a good "black friday" offer in EU for even the old version of this ADI-2 ......... preferably below 700€ ??????
You're dreaming.;)
Since its launch, almost 2 years ago, I never saw the ADI-2 DAC cheaper than 900€, whatever it was during Black Friday, Christmas, Summer Sales or whatever.
Bax Music actually sells the ADI-2 DAC at 959€ (40€ off), but they confirmed it was the last stock of the V1.
 

Bliman

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As you mention using SPDIF coax, check the State Overview. SP c should show (for CD): 'sync 44.1 cons 16' and Clock Source should show 'SPDIF coax'.

Also, try using the USB connection and see if your impressions remain the same.
Checked the settings and they matched with your suggestion. Thanks for the suggestion.
 

Bliman

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6dB is a lot, if this is not overtly noticeable then something is very wrong somewhere but I can't tell you what from here.

Blown a tweeter? But of course that doesn't tally with you saying it sounds bright.
I checked again. And I switched from -6dB to +6dB in the treble. And I couldn't hear a difference. I know checked the same on the computer with APO and I can definitely hear a difference between -6dB and +6dB in the treble region of 8 KHz but not 16 KHz. Which is pretty normal I think. I don't know what treble region RME is toning down with the tone controls.
 

VintageFlanker

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I checked again. And I switched from -6dB to +6dB in the treble. And I couldn't hear a difference
That's very weird, indeed. Maybe this specific function is defective with your unit. In addition, why not tweaking the EQ? I guarantee both Treble/Bass and EQ worked great with my Rev1 (I use the unit with stock settings anyway). +6db with any frequency is not a very good idea anyway.
Also, this will overload the digital level in some cases.

My Rev2 will be delivered in a couple of days. Will check that out of the box.
 

Bliman

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I am going to buy a microphone and will test further in the weekend (if it gets delivered so fast).
I will also try to connect the laptop to it to test it. I just want to know how I could loop it like amirm says to test if everything is correct.
I will also then connect the Grace Design and see if I am not just imagining things.
Thanks all.
 

Bliman

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That's very weird, indeed. Maybe this specific function is defective with your unit. In addition, why not tweaking the EQ? I guarantee both Treble/Bass and EQ worked great with my Rev1 (I use the unit with stock settings anyway). +6db with at any frequency is not a very good idea anyway.
Also, this will overload the digital level in some cases.

My Rev2 will be delivered in a couple of days. Will check that out of the box.
Yeah I checked the EQ yesterday with the headphone. And it worked great. So maybe I am going deaf or something :) .
You have to enable the treble/bass tone on the remote or it doesn't work (you could enable it on the unit itself naturally) and you can then change the treble and bass. I will test it again now.
 
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I checked again. And I switched from -6dB to +6dB in the treble. And I couldn't hear a difference. I know checked the same on the computer with APO and I can definitely hear a difference between -6dB and +6dB in the treble region of 8 KHz but not 16 KHz. Which is pretty normal I think. I don't know what treble region RME is toning down with the tone controls.

If you push Button 1, what does it display regarding B & T? For Line out that is.

12.3 Subpage Bass / Treble B/T Enable
OFF, ON. Default: ON
Bass Gain
Current Bass amplification for the current channels as set by encoder 1 (B). Adjustable between -6 dB and +6 dB in steps of 0.5 dB.
Bass Freq
Corner frequency of the shelf bass filter. Adjustable from 20 Hz to 150 Hz in steps of 1 Hz. De- fault: 85 Hz.
Bass Q
The quality factor of the filter is adjustable from 0.5 to 1.5. Default 0.9.
Treble Gain
Current Treble amplification for the current channels as set by encoder 2 (T). Adjustable between -6 dB and +6 dB in steps of 0.5 dB.
Treble Freq
Corner frequency of the shelf treble filter. Adjustable from 3 kHz to 10 kHz in steps of 100 Hz. Default: 6.5 kHz.
Treble Q
The quality factor of the filter is adjustable from 0.5 to 1.5. Default 0.7.
 
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ShiZo

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That's very weird, indeed. Maybe this specific function is defective with your unit. In addition, why not tweaking the EQ? I guarantee both Treble/Bass and EQ worked great with my Rev1 (I use the unit with stock settings anyway). +6db with any frequency is not a very good idea anyway.
Also, this will overload the digital level in some cases.

My Rev2 will be delivered in a couple of days. Will check that out of the box.

Will you let me know what you think? I'm thinking about upgrading as well.
 

Willem

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Bliman, did you pose your question on the RME forum or write to RME? They are very responsive.
 
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