This is a review and detailed measurements of the updated version 2 of the RME ADI-2 FS DAC and headphone amplifier. It was kindly sent to me by the company. The cost us US $1,149.
The ADI-2 looks very nice in black with a bright, super responsive display (doesn't come out as well in the picture):
I usually only focus on performance of audio products and DACs don't have much to talk about anyway. Not so with RME products. There are tons and tons of features including two different headphone outputs with automatic detection and settings. There is a built-in parametric EQ which can help you optimize your room or headphones. And on and on.
The display is highly informative which I appreciate. I like to know what my settings are, sample rate, volume, etc. at a glance and they are all here and then some.
Soft white LEDs surround the power button, the main rotary controller and backlight for the switches.
A nice reassuring set of relays click on power on. A compact 12 volt, 2 amp power supply with a clever locking mechanism comes with the unit. As does a remote control (which I did not use).
The back panel is tidy:
Of course the product is made in Germany which makes availability much better for our EU members. Support is superb on our forum and RME's own and company makes frequent updates to the unit through firmware updates.
Overall, this is a beautiful DAC with extensive feature list.
DAC Audio Measurements
Let's start with our usual dashboard of 1 kHz tone and measure what comes out of the XLR balanced connectors (used for all the DAC tests):
The distortion level now is state of the art with levels at -130 dB (15 dB better that best case human hearing). Noise level is higher though and dominates, resulting in SINAD of 115 dB. This is 3 dB better than version one of this DAC so definitely improved but not the best we have seen:
Yellow is the version 2 under test, and purple is the older one.
The reason noise level is not as good as seemingly cheaper DACs is because the ADI-2 is a pro product and can produce much higher output level. When we let it loose this way, performance improves yet again:
SINAD reaches a maximum of 117 dB now with nearly 7 volts output. You can use this higher level output with amplifiers like Benchmark, Purifi, hypex ncore, etc. to get the best performance out of them.
We can see that in our dynamic range tests:
IMD test is likewise impacted by the output level although it is excellent both ways:
There is tiniest hint of jitter (hugging our main tone of 12 kHz and a pair at 6.2 and 17.8 kHz) but at -140 dB and lower, are utterly inaudible:
32-tone test resembling "music" shows very low levels of intermodulation distortion:
Linearity is essentially perfect to the maximum level I measure:
There are a set of filters. In the interest of time, I just tested the default:
THD+N versus frequency is low but perhaps not as perfect as it could be:
Headphone Amplifier Measurements
Since there is no analog input, these measurements are the combination of the performance of the DAC plus the headphone amplifier. With stand-alone analog headphone amplifiers, you would lose a few dBs of performance when you pair a DAC with them. Also, the volume control here is digital which means channel matching is excellent unlike analog solutions.
Let's start with our usual power measurement into 300 ohm:
310 milliwatts of power into 300 ohm is superb as my threshold of excellence is 100 milliwatts. This means you can drive high impedance headphones with ease. Combined DAC+amp in high power clocks at 110 dB SINAD which is just shy of best case theoretical threshold of hearing (again, 115 dB).
If you want lower noise, you can use the IEM output in low power mode (blue):
You have three nice settings for three different scenarios.
Switching to 33 ohm load we get:
We have 1.5 watts of power which should be good for most headphones. I did not bother to test the IEM output as the low power mode (red) already had excellent low noise performance.
I was surprised that with 50 millivolts output, performance was not as good as version 1:
I use different fixtures to wire up to my analyzer so perhaps that is the reason for slight regression. Still, what is there at 89 dB, beats majority of headphone amplifiers out there.
I did not bother to measure the output impedance and trust the RME spec of it being near zero.
Headphone Listening Tests
I started testing with my Sennheiser HD-650. Wow, these sounded super with incredible amount of power available on tap. I had no trouble getting my ear lobes to resonate with bass heavy music!
If I did not fear for quick loss of hearing, I would listen that way for hours. Ample power, low noise and distortion meant great dynamic range, detail, lack of noise, etc. Everything reflected the fidelity of the source.
I then switched to my super inefficient and low impedance (25 ohm) Ether CX headphone. Here performance was very good but I could get the amp to distort. Granted, by then it was too loud for me to tolerate but still, I like to see some headroom there. Again, these are super difficult headphones to drive.
Conclusions
The RME ADI-2 FS V2 improves on the first generation design in lowering distortion levels. The slick look and huge feature list is a major add-on which doesn't exist in DAC-only products. Headphone amplifier is very powerful and is able to drive most headphones with authority and high fidelity. No records have been broken on the performance though.
Overall combination of features and performance pushes me to give the RME ADI-2 FS DAC V2 my strong recommendation. Indeed, I am still listening to it as I type this and will make it my everyday DAC+amp at my workstation.
-----------
As always, questions, comments, recommendations, etc. are welcome.
I have packed so many heavy and big boxes and dropped off at UPS store that I am starting to feel sorry for the guy there and want to buy him a gift. So please donate a few dollars toward that if you can. Be on notice though that I might be tempted to keep said money and just use it for myself. Here is the link: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The ADI-2 looks very nice in black with a bright, super responsive display (doesn't come out as well in the picture):
I usually only focus on performance of audio products and DACs don't have much to talk about anyway. Not so with RME products. There are tons and tons of features including two different headphone outputs with automatic detection and settings. There is a built-in parametric EQ which can help you optimize your room or headphones. And on and on.
The display is highly informative which I appreciate. I like to know what my settings are, sample rate, volume, etc. at a glance and they are all here and then some.
Soft white LEDs surround the power button, the main rotary controller and backlight for the switches.
A nice reassuring set of relays click on power on. A compact 12 volt, 2 amp power supply with a clever locking mechanism comes with the unit. As does a remote control (which I did not use).
The back panel is tidy:
Of course the product is made in Germany which makes availability much better for our EU members. Support is superb on our forum and RME's own and company makes frequent updates to the unit through firmware updates.
Overall, this is a beautiful DAC with extensive feature list.
DAC Audio Measurements
Let's start with our usual dashboard of 1 kHz tone and measure what comes out of the XLR balanced connectors (used for all the DAC tests):
The distortion level now is state of the art with levels at -130 dB (15 dB better that best case human hearing). Noise level is higher though and dominates, resulting in SINAD of 115 dB. This is 3 dB better than version one of this DAC so definitely improved but not the best we have seen:
Yellow is the version 2 under test, and purple is the older one.
The reason noise level is not as good as seemingly cheaper DACs is because the ADI-2 is a pro product and can produce much higher output level. When we let it loose this way, performance improves yet again:
SINAD reaches a maximum of 117 dB now with nearly 7 volts output. You can use this higher level output with amplifiers like Benchmark, Purifi, hypex ncore, etc. to get the best performance out of them.
We can see that in our dynamic range tests:
IMD test is likewise impacted by the output level although it is excellent both ways:
There is tiniest hint of jitter (hugging our main tone of 12 kHz and a pair at 6.2 and 17.8 kHz) but at -140 dB and lower, are utterly inaudible:
32-tone test resembling "music" shows very low levels of intermodulation distortion:
Linearity is essentially perfect to the maximum level I measure:
There are a set of filters. In the interest of time, I just tested the default:
THD+N versus frequency is low but perhaps not as perfect as it could be:
Headphone Amplifier Measurements
Since there is no analog input, these measurements are the combination of the performance of the DAC plus the headphone amplifier. With stand-alone analog headphone amplifiers, you would lose a few dBs of performance when you pair a DAC with them. Also, the volume control here is digital which means channel matching is excellent unlike analog solutions.
Let's start with our usual power measurement into 300 ohm:
310 milliwatts of power into 300 ohm is superb as my threshold of excellence is 100 milliwatts. This means you can drive high impedance headphones with ease. Combined DAC+amp in high power clocks at 110 dB SINAD which is just shy of best case theoretical threshold of hearing (again, 115 dB).
If you want lower noise, you can use the IEM output in low power mode (blue):
You have three nice settings for three different scenarios.
Switching to 33 ohm load we get:
We have 1.5 watts of power which should be good for most headphones. I did not bother to test the IEM output as the low power mode (red) already had excellent low noise performance.
I was surprised that with 50 millivolts output, performance was not as good as version 1:
I use different fixtures to wire up to my analyzer so perhaps that is the reason for slight regression. Still, what is there at 89 dB, beats majority of headphone amplifiers out there.
I did not bother to measure the output impedance and trust the RME spec of it being near zero.
Headphone Listening Tests
I started testing with my Sennheiser HD-650. Wow, these sounded super with incredible amount of power available on tap. I had no trouble getting my ear lobes to resonate with bass heavy music!
If I did not fear for quick loss of hearing, I would listen that way for hours. Ample power, low noise and distortion meant great dynamic range, detail, lack of noise, etc. Everything reflected the fidelity of the source.I then switched to my super inefficient and low impedance (25 ohm) Ether CX headphone. Here performance was very good but I could get the amp to distort. Granted, by then it was too loud for me to tolerate but still, I like to see some headroom there. Again, these are super difficult headphones to drive.
Conclusions
The RME ADI-2 FS V2 improves on the first generation design in lowering distortion levels. The slick look and huge feature list is a major add-on which doesn't exist in DAC-only products. Headphone amplifier is very powerful and is able to drive most headphones with authority and high fidelity. No records have been broken on the performance though.
Overall combination of features and performance pushes me to give the RME ADI-2 FS DAC V2 my strong recommendation. Indeed, I am still listening to it as I type this and will make it my everyday DAC+amp at my workstation.
-----------
As always, questions, comments, recommendations, etc. are welcome.
I have packed so many heavy and big boxes and dropped off at UPS store that I am starting to feel sorry for the guy there and want to buy him a gift. So please donate a few dollars toward that if you can. Be on notice though that I might be tempted to keep said money and just use it for myself.
Here is the link: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
