RME ADI-2 FS Version 2 DAC and Headphone Amp Review

[pkane]

Yes, you can disable everything and run as a pure DAC if you wish.

You can even put ADI-2 Pro into a loopback mode where the data will not be converted to analog and instead, passed through as a bit-perfect digital stream if real purity is what you're after

 

[kolestonin]

Bit of a waste of potential, though....

maybe not just a bit

But I had a tiny doubt that device can be used with absolute 0 filters and I wanted a confirmation.
In plus, as I will receive a used unit to try, I wanted to be sure on what I need to disable in order to check it as a pure DAC before applying any EQ.

 

[kolestonin]

You can even put ADI-2 Pro into a loopback mode where the data will not be converted to analog and instead, passed through as a bit-perfect digital stream if real purity is what you're after

Is this valid for the non pro version as well?

 

[pkane]

Is this valid for the non pro version as well?

I think it's Pro only, although to be clear, mine wasn't a serious suggestion

 

[Trell]

Is this valid for the non pro version as well?

He was joking, but you can configure the DAC loopback to have USB input appear on the SPDIF as input that can be recorded. This is at times useful functionality to have.

 

[AlexDD]

Great as expected. The only thing disappointing to me about this the lack of internal power supply, and no headphone balanced out, although I wouldn't expect to see that in an RME product, however minor. Given the market I would also have thought it could at least have AES in.

The advantage of the chifi stuff like Topping D90/A90 stack etc., seems to be a more robust enclosure, more inputs, wireless, MQA, and a bit more power but at $100-200 more. I'm excited to see how the upgrade of a DX7 Pro (DX9 Pro? - based on D90/A90) will compete with this, as an all-in-one solution. There is a bit of a void in the market when it comes to high performing amp/dac combos.

What's AES?

 

[Matias]

What's AES?

AES-EBU is the common name for XLR balanced digital connection.

 

[AlexDD]

Depends on what you mean by a pre amp?

The ADI-2 DAC fs is a DAC with DSP, i.e. it has selectable digital inputs and analogue output that can be used to drive a power amp directly, the DAC has a built-in volume and DSP tone control, so in a sense the DAC can be used to select /control your digital signals and feed a power amp, but it has no analogue input.

The ADI-2 PRO fs is similar to the DAC above, but also includes an analogue input, so this can be used as a basic one analogue stereo input 'pre amp' with volume and DSP tone control.

NB. I have just checked the RME web site and the ADI-2 PRO fs is shown as discontinued, perhaps they are bringing out a new version.

Do you mean that this DAC is also a pre amp and can be connected to any amplifier? Did I understand correctly?
Any recommendations of power amplifiers (around 100W) to pair up with this ADI-2 DAC fs?

 

[roog]

Do you mean that this DAC is also a pre amp and can be connected to any amplifier? Did I understand correctly?
Any recommendations of power amplifiers (around 100W) to pair up with this ADI-2 DAC fs?

It depends on what you mean by a ‘pre amp’. I think most people consider a traditional pre amp should have, multiple selectable analogue inputs, a line level amplifier with volume control perhaps some tone controls and an output or two able to drive a power amp.

The RME ADI-2 DAC fs does not have analogue inputs, but it does have digital inputs, a volume control and sophisticated EQ/ tone controls implemented in DSP and it is able to drive a power amp directly, either via a balanced or unbalanced outputs.

I only have one digital source, so the RME ADI-2 DAC fs serves the purpose of DAC, EQ, volume control, low distortion, and low impedance output to drive my power amp.

I understand that RME produced a very similar product ‘the pro model’ which included one analogue input, again this would not be everyones idea of a pre amp, this product incorporates an analogue to digital converter (ADC) which converts the analogue input signal to digital and i believe the rest of the unit is similar to the ADI-2 DAC fs which then treats the digitised analogue input as just another digital input. Having owned the ADI-2 DAC fs for a few years I would consider the purchasing the ‘pro’ model which has the analogue input as I could use this to connect my single analogue source for occasional use.

Check out the RME web site and excellent forum for latest updates and advice, the forum admins are very helpful if a little direct at times, I recommend reading the downloadable manual for these devices, because that is what everyone will tell you to do and because they are very comprehensive, just like the good o’l days!

Happy DAC hunting, actually don’t hunt for a DAC if you need/want the flexibility that the RME offers, just buy one, I can’t think of another DAC which offers this capability. :0)

As for selecting a ‘compatible‘ power amp, I currently use a class A/B power amp with my ADI-2 DAC fs, but I am seriously considering buying one of the newer class D amps such as the NAD C298 or M23. Just because I like the idea of running a very low distortion amp. There are other lower cost options from SMSL, and Sabaj, or if you want a class A/B amp the Topping PA90 appears to perform very well. I have not tried any of these options with the ADI-2 DAC fs but I suspect that any of these would work just fine subject to selecting a suitable power output to drive your speakers.

 

[Count Arthur]

I would consider the purchasing the ‘pro’ model which has the analogue input as I could use this to connect my single analogue source for occasional use.

Maybe use something like this with your existing DAC: https://www.thomann.de/gb/swissonic_converter_ad_24_192.htm

 

[roog]

Maybe use something like this with your existing DAC: https://www.thomann.de/gb/swissonic_converter_ad_24_192.htm

Yes that looks like a neat add on, TBH, despite my turntable still being in my living room I have not felt the need to spin discs for years.

 

[rcstevensonaz]

It depends on what you mean by a ‘pre amp’. I think most people consider a traditional pre amp should have, multiple selectable analogue inputs, a line level amplifier with volume control perhaps some tone controls and an output or two able to drive a power amp.

I would propose a slight edit on definition of a traditional pre amp: multiple selectable (or mixable) analog and/or digital inputs and (optionally) outputs, ...

Which is the RME ADI-2 Pro FS.

 

[Deleted member 4708]

Question on RME ADI2 DAC fs: Can the digital inputs be routed back to the PC through USB?

 

[AlexDD]

It depends on what you mean by a ‘pre amp’. I think most people consider a traditional pre amp should have, multiple selectable analogue inputs, a line level amplifier with volume control perhaps some tone controls and an output or two able to drive a power amp.

The RME ADI-2 DAC fs does not have analogue inputs, but it does have digital inputs, a volume control and sophisticated EQ/ tone controls implemented in DSP and it is able to drive a power amp directly, either via a balanced or unbalanced outputs.

I only have one digital source, so the RME ADI-2 DAC fs serves the purpose of DAC, EQ, volume control, low distortion, and low impedance output to drive my power amp.

I understand that RME produced a very similar product ‘the pro model’ which included one analogue input, again this would not be everyones idea of a pre amp, this product incorporates an analogue to digital converter (ADC) which converts the analogue input signal to digital and i believe the rest of the unit is similar to the ADI-2 DAC fs which then treats the digitised analogue input as just another digital input. Having owned the ADI-2 DAC fs for a few years I would consider the purchasing the ‘pro’ model which has the analogue input as I could use this to connect my single analogue source for occasional use.

Check out the RME web site and excellent forum for latest updates and advice, the forum admins are very helpful if a little direct at times, I recommend reading the downloadable manual for these devices, because that is what everyone will tell you to do and because they are very comprehensive, just like the good o’l days!

Happy DAC hunting, actually don’t hunt for a DAC if you need/want the flexibility that the RME offers, just buy one, I can’t think of another DAC which offers this capability. :0)

As for selecting a ‘compatible‘ power amp, I currently use a class A/B power amp with my ADI-2 DAC fs, but I am seriously considering buying one of the newer class D amps such as the NAD C298 or M23. Just because I like the idea of running a very low distortion amp. There are other lower cost options from SMSL, and Sabaj, or if you want a class A/B amp the Topping PA90 appears to perform very well. I have not tried any of these options with the ADI-2 DAC fs but I suspect that any of these would work just fine subject to selecting a suitable power output to drive your speakers.

You perfectly answered my questions, thank you very much!

 

[Trell]

Question on RME ADI2 DAC fs: Can the digital inputs be routed back to the PC through USB?

Yes. I’ve used that for recording the TOSLINK input.

 

[Deleted member 21726]

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):

View attachment 63548

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:

View attachment 63550

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):

View attachment 63551

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:

View attachment 63553

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:

View attachment 63554

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:
View attachment 63555

IMD test is likewise impacted by the output level although it is excellent both ways:
View attachment 63556

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:
View attachment 63557

32-tone test resembling "music" shows very low levels of intermodulation distortion:
View attachment 63558

Linearity is essentially perfect to the maximum level I measure:
View attachment 63559

There are a set of filters. In the interest of time, I just tested the default:

View attachment 63560

THD+N versus frequency is low but perhaps not as perfect as it could be:

View attachment 63565

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:

View attachment 63561

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):

View attachment 63562

You have three nice settings for three different scenarios.

Switching to 33 ohm load we get:
View attachment 63563

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:
View attachment 63564

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/

Is there self powered usb? I mean does my iPad or iPhone work with this just "plug and play"-style?

 

[Atanasi]

Is there self powered usb? I mean does my iPad or iPhone work with this just "plug and play"-style?

DAC is self-powered, so it has its own power supply and doesn't consume bus power.

 

[roog]

You perfectly answered my questions, thank you very much!

My pleasure, I really rate the RME ADI-2 DAC, can you tell? :0)

 

[Deleted member 21726]

Just purchased used v1! That’s my final amp.

Edit: Is there any harm done if i put RME upright position? Warming etc.

 

[withoutsuit]

Would it be able, to set different delays at the outputs? I use a double bass array and would need 2 delays for the sub arrays.