RME ADI-2 Pro is not your typical audio interface, that’s the first thing to get out of the way. At the same time it is a lot of things and manages to do all of them brilliantly. In one word the ADI-2 Pro is a signal converter. It can take just about any digital or analog signal and convert it into any other type. Sounds boring, right? Read on to find out why it’s anything but and why I’ll be getting one.

 

 

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RME at its best

If you’re a regular at pro audio forums, then you most likely know that RME gear isn’t the most common recommendation for newbies. Rock solid drivers and minuscule latency is something you can appreciate best if you’ve been burned by cruddy performance. We at Sonarworks have been relying on RME Babyface and Fireface UC units to not leave us with our pants down in studio tours. And boy did they deliver!

When I first used the Babyface I was pleasantly surprised by it’s DAC and headphone output. Of course it wasn’t in the same league as some of the hi-fi offerings for the same price, but considering that it’s USB powered, much could be forgiven. Fireface UC was an incremental step up, once I tried that out.

Now, enter the ADI-2 Pro. Both line and headphone outputs are audibly impeccable. Over the years I’ve tried many dozens of DACs and headamps and there’s only one thing I ask from gear – lack of coloration. After hours of music I shouldn’t be able to hear a common coloration in the material I listen to. ADI-2 Pro nails this. Now let’s talk about the each of major features of this unit.

 

IO galore

ADI-2 Pro is pretty versatile and runs off USB 2.0, I imagine that for most folks that will be the main connection to their workstations. Other digital inputs like AES/EBU, SPDIF and optical are present as well and can use incoming clock or use RME SteadyClock III for reclocking. Optical from my Macbook Pro was audibly inferior when ADI-2 Pro wasn’t using its inner clock, so it was a relief to improve the sound just by switching clocks. I’d recommend always sticking to inner clock, save for very high quality sources.

 

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Pair of analog inputs are there if one needs quality digital capture or just hooking up the ADI-2 Pro to an analog source. Analog outputs is where things get interesting. The unit has 4 channel DAC capabilities, but only 2 channels are routed to back XLR or TRS jacks. One DAC is reserved for headphone use only, so one can set different DSP settings for headphones and speakers, which are switched depending on wether a headphone jacks is detected. I found it very handy for my system where speakers aren’t feasible for late night listening.

When using ADI-2 Pro one needs to keep in mind that this unit uses pre-made routings for all channels rather than the flexible TotalMix matrix RME users have grown (and learned) to love. In my opinion it’s an understandable trade-off if RME aims at home audio. I remember my first encounter with TotalMix and it took a few +0dB blasts from my main monitors, before I learned how to use it. Even when used in standalone, the ADI-2 Pro AD/DA and preamp routing schemes didn’t leave me wanting one bit.

 

Clean juice for any can

One of the main requirements for a headphone amp is driver control at high power levels. Some might argue that with modern headphones being reasonably efficient that’s not true. Yes and no. With DSP calibration efficiency drops around -10dB are common. That’s 10 times more power to achieve the same SPL! Even if your headphone amp can do it, will it do so without losing composure?

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ADI-2 Pro uses OPA1688 Texas Instruments opamps per channel to deliver the goods. It’s one of their newer opamps and is designed for headphone use. To my knowledge ADI-2 Pro is the only commercial product using these parts. What’s interesting – to achieve even better performance 3 of these chips are used per channel! Should you be interested in balanced headphone drive, the load will be distributed to all 12 chips from 2 outputs. Max power is 3W at 64 Ohm load, which was more than enough for everything we tried.

Headphone wise the ADI-2 Pro does everything I’d ever need. It even supports dual headphone mode which is a real treat for reviewers. I can set separate volume settings for each of the front outputs to achieve perfect SPL matching. This way I don’t need two amps for quick comparisons. Overall this is the finest headphone listening solution I’ve ever tried.

 

Transparent monitoring

So, what about monitor loudspeakers? Pretty much the same. Unfortunately my Equator Q12 speakers are digital, so I can’t fully appreciate the DAC in this unit. Same goes for a pair of Dynaudio BM5 III we have in our control room. Curiously enough there was a marked jump in quality when going from my MiniDSP 2x4HD to ADI-2 Pro. Most notably imaging became tighter and highs lost some glare.

Especially useful for monitoring is the built-in 5 band parametric EQ. I was able to dial it in to combat most of the room modes in my listening room. Having used Reference 3 measurement software I was able to get a good idea where trouble lurks and 5 bands were enough to get a good “generic” curve. Mind you – for critical stuff I still prefer using speaker calibration, it’s a subtle difference, but if you’re reading this review then there’s a good chance you’ll be able to appreciate it.

 

Capture everything

So far I’ve been writing about the ADI-2 Pro like it was an extremely proficient monitor controller. However, on the back of the unit there are analog input combo jacks. The easy way out would’ve been to just route these to the headphone amp and through a volume control to main monitor outs. That’s not the case with ADI-2 Pro, it’s equipped with the finest ADC stage RME could design.

RME co-founder Matthias Carstens explained me that converting analog inputs to digital does more good than bad. First of all you get precision digital volume control, secondly you can do EQ, loudness compensation and other kinds of magic to the said signal. Thirdly – with ADI-2 Pro you have a state of the art ADC for your recording needs!

Just keep in mind you have only 2 channels of line level inputs without mic preamps. As I was saying – this isn’t an audio interface. It can find it’s place in mastering houses where you have a truckload of outboard gear and need something to capture 2 channels as cleanly as possible. Then there are two other possible scenarios – electronic measurements and vinyl ripping. Both of these benefit from high SNR and low THD.

 

Why it works for me

After weeks of rigorous testing the ADI-2 Pro impressed me enough to become the reference unit here at Sonarworks. Our calibration software is developed on the basis of solid engineering, but it always needs to be checked by ear. We can always trust this device to leave no trace of its own in the output. Also our other gear can be periodically checked via ADI-2 Pro’s super clean ADC, so we can be sure it works as intended.

Will it work for you? If you’re after the best, consider the ADI-2 Pro. However, I will admit that one can make do with much less. If you don’t need the ADC, EQ and a slew of other features, a separate DAC and headamp might save you some cash. Just make sure that at some point you don’t audition the ADI-2 Pro, there’s a good chance you won’t be able to go back.

Pros:

  • Audibly transparent DAC and headamp stage
  • State of the art ADC capture
  • Fully configureable from the unit itself
  • Plenty of power and gain for just about any headphone out there
  • Nearest competitor more expensive and larger
  • Records and plays all digital formats
  • Future improvements via firmware upgrades

Cons:

  • No mic preamps
  • No remote

More info here: https://www.rme-audio.de/en/products/adi_2-pro.php

ADI-2 Pro threads:

SBAF: http://www.superbestaudiofriends.org/index.php?threads/rme-adi-2-pro-discussion-thread.3160/

Gearslutz: https://www.gearslutz.com/board/product-alerts-older-than-2-months/1078983-rme-announce-new-adi-2-pro-2-channel-converter.html

Head-Fi: http://www.head-fi.org/t/837026/rme-adi-2-pro-dac-headamp-an-a-lot-of-more-stunning-features

  • Dalí Plazas

    Great review. For speaker/room calibration, you need an external measuring software/hardware combo and, then, using the combo’s room measurements, create (and save) a suitable correction EQ profile using the RME’s parametric equalizer, right?

    • admin

      Thanks! Here’s how I did it:

      1. Hook everything up with RME’s EQ disabled
      2. Measure the “natural” room response
      3. Translate these measurements to a 5 band parametric EQ
      4. Remeasure with ADI-2 Pro EQ enabled
      5. Verify that the EQ addresses main flaws of room response, repeat last 2 points until they do
      6. Use the Sonarworks plug-in or Systemwide when you absolutely need critical tonal response

      P.S. Keep in mind that RME ADI-2 Pro EQ isn’t phase linear. If you need phase linear EQ, stick to Sonarworks.