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

[ShiZo]

I have old rme adi 2 from 2005...........used to consider it cold, metallic or something like that, just like you.....until I tested some xlr cables...I go straight to active studio monitors.............Better ones made the difference, and now its breathtaking every time without faults even though old tech..........frequenzy spectrum is perfect............they will say this is bs, but thats my experience......I dont wanna mention any brands so they dont blame me, so google yourself......and try.......it could be that rme is actually more accurate (than d90) and will sound little harsh if the cables arent spot on......

The d90 is not less accurate than the rme. What gives you that impression?

 

[Oukkidoukki]

And i would probably skip the freya for highest fidelity.....and cables to speakers must be mega too

 

[ReaderZ]

I’ve been subjectively comparing the D90 MQA and the ADI-2 v2 with the A90 and headphones, and in my speaker system. In the speaker system it feeds a Freya S in passive mode followed by Nord SE Purifi monos powering SB Accustics ARA Be and a pair of REL subs; analog connections Hypex balanced XLR cables and Supra speaker cables (I like the Swedish pale blue).

Both DACs are set with fixed output and the ADI-2 has its Ref Level at +7dB.

With the A90 and headphones, I can’t tell both DACs appart. They are equally resolving and detailed with no apparent sonic signature.

Now, in my speaker system the ADI-2 set as a DAC gives me listening fatigue pretty quickly. And it doesn’t sound as “rounded” as the D90. It feels like it is picking up some high frequency noise or generating distortion at high frequencies. Now, bypassing the Freya S and using it as a DAC/Pre combo directly connected to the Purifi monos doesn’t give me listening fatigue - that might be the right combination BTW...

I’m not sure what’s going on, I don’t have any equipment I can use to measure. I’m just curious to know if any one has a huntch of what could be going on. Could it be a faulty ground connection somewhere? Could the Freya S be picking up or generating noise affecting the ADI-2 (the D90 seems immune to it)? Would star quad XLR cables help isolate DAC and amps from possible interference?

Here are diagrams showing what the whole system looks like with and without the Freya S:

View attachment 67138

View attachment 67139

It's hard to say how much negative impact Freya S have on the sound, but one thing for sure is it will not make the sound better in any way, and you also don't like it, I would suggest remove it from signal chain.

 

[Oukkidoukki]

The d90 is not less accurate than the rme. What gives you that impression?

Rme engineering and reputation......but dont wanna argue, point was just that accurate dac can sound harsh or cold or what ever if cabeling is off ( because dac is so truthful in its presentation, hasnt been tuned for bad cabling abd tech) hard to explain....

 

[ShiZo]

Well, I've owned the adi 2 dac v1, v2 and smsl m400 which is a ak4499 variant. And I never got that impression from listening or from measurements.

They are all awesome devices in their own right though.

 

[VintageFlanker]

Rme engineering and reputation......but dont wanna argue, point was just that accurate dac can sound harsh or cold or what ever if cabeling is off ( because dac is so truthful in its presentation, hasnt been tuned for bad cabling abd tech) hard to explain....

Alright.
@amirm, would you please measure "reputation" with your AP for the next review?

Any examples of defective cables vs non-defective ones?

 

[LTig]

Rme engineering and reputation......but dont wanna argue, point was just that accurate dac can sound harsh or cold or what ever if cabeling is off ( because dac is so truthful in its presentation, hasnt been tuned for bad cabling abd tech) hard to explain....

If an accurate DAC sounds harsh it's the recording or the speakers, but not the cable - at least not with the RME where the output impedance is too low to allow an audible damping of frequencies above a few kHz, even with longer cables.

 

[EchoChamber]

I have old rme adi 2 from 2005...........used to consider it cold, metallic or something like that, just like you.....until I tested some xlr cables...I go straight to active studio monitors.............Better ones made the difference, and now its breathtaking every time without faults even though old tech..........frequenzy spectrum is perfect............they will say this is bs, but thats my experience......I dont wanna mention any brands so they dont blame me, so google yourself......and try.......it could be that rme is actually more accurate (than d90) and will sound little harsh if the cables arent spot on......

Good feedback. I have some bulk pro microphone cable on order, I'll built a set and see what comes out of it. Also I'll compare to other star quad and dual conductors microphone cable I've already built and used. To be fair, the Beryllium tweaters in my speakers are ruthless. Not all music sounded worst, maybe it is just too revealing for day to day usage. Amazon HD somehow sounded more relaxed and laid back than Tidal with the RME. It's a great unit and I'm adicted to the level of transparency I get from it. I mean, acoustic instruments are just out of this world... I just listened to a track from Caetano and David Byrne live at Carnegie Hall that sounded breathtaking through the ADI-2 (dac/pre) driving the Purifi monos...

 

[EchoChamber]

It's hard to say how much negative impact Freya S have on the sound, but one thing for sure is it will not make the sound better in any way, and you also don't like it, I would suggest remove it from signal chain.

I've always tried to be a minimalist audiophile, the Freya S in passive mode should be 100% transparent, but taking it out of the equation means one less cable, one less PCB and a bunch of switches, a power supply (not used for passive duty), etc... Not counting the RME ADI-2 perfectly balanced volume control and other great features.

 

[EchoChamber]

ADI-2 is back at the core of the system, my challenge will be to make it work, it’s just tooo good to pass! I’m using a pair of XLR built with Canare microphone cable I had (2 conductor, not star quad). Small change... I also reduced toe in from my speakers a few degrees. I guess i need to re-evaluate some decisions I made before the ADI-2.

 

[eliash]

Yes, indeed.

And there is also the cheaper ADI-2 (non Pro) fs
There used to be a non-fs version of this one too, but that was a long time ago.
This is most probably too limited for home use, though.
(There is no USB interface)
This is more a Pro-market or Home-Studio-market device.

I´m using that device as master DAC(ADC) in my stereo setup, no complaints. Even in combination with the supplied switching power supply it shows no flaws, i.e. no audible beat tones up to 80KHz digital sweeps. Adaptation to the 800mV reference/clipping level of my amp is done via ~7dB precision resistor attenuators in the XLR connector (>2KOhm input impedance, ~600Ohms output) with +13dB output setting. This improves the S/N and channel balance a bit over using the vol. pot.
The ADC is used for phono measurement & recording and driving the tc-electronic Clarity M analyser via S/PDIF from the analog preamp' s rec outputs.
USB - S/PDIF conversion in both directions is done via inexpensive C-Media-based bit-perfect converters (~50€ each).

...An interesting thing would be to upgrade the DAC Chips AK4490 towards AK4493, they look pin-compatible and the main functions used in that ADI box look common!? Any comments?...

 

[Veri]

...An interesting thing would be to upgrade the DAC Chips AK4490 towards AK4493, they look pin-compatible

They're not though.

 

[eliash]

They're not though.

Yes, not completely, but would it matter?

 

[Veri]

Yes, not completely, but would it matter?

I believe RME in their forum said that one can't just change 4490 to 4493, the entire design needs changes. So unfortunately it's not as easy as swapping chips.

 

[eliash]

....saw this as well, but if I remember correct, it was meant for the "advanced" models with changeable filters and so on. The ADI-2 fs is a simple implementation up to 192Kb/s on the DACside, no fancy features to be controlled...


...guess MC wouldn´t comment, if possible...

 

[LTig]

IUSB - S/PDIF conversion in both directions is done via inexpensive C-Media-based bit-perfect converters (~50€ each.

Do you have a link where I could buy these converters?

 

[eliash]

Do you have a link where I could buy these converters?

The USB to SPDIF is from CN, bought it some years ago, but there should be many offers around from the usual DIY sources.

The other direction was somewhat more challenging, but I found this one, which works fine after the usual config hassle:
Converter It has TOSLINK, drivers on their homepage


...just noticed it has become somewhat more expensive, I paid some 45€ 55.77€ last year (@ Jacob-Elektronik), eventually more search will help...

 

[frogmeat69]

If it only looked like HiFi and not like a lab equipment for chemistry....

I think it's the best looking part of my desktop headphone set up, much more attractive than the Monoprice amp and Koss electrostat energizer.

 

[Rja4000]

An interesting thing would be to upgrade the DAC Chips AK4490 towards AK4493

That's exactly what RME did with new generation of tge ADI-2 DAC and with the Pro fs R.
That's new design, though.
I don't know if they have a newer version of the ADI-2 fs (non Pro)

 

[Rja4000]

Adaptation to the 800mV reference/clipping level of my amp is done via ~7dB precision resistor attenuators in the XLR connector (>2KOhm input impedance, ~600Ohms output) with +13dB output setting. This improves the S/N and channel balance a bit over using the vol. pot.

I'm not sure there is a benefit of using the +13dBu range

Here is 800mV input, measured with ADI-Pro fs R (Black) and ADI-Pro fs (Red) ADC, using range +4dBu
(+4dBu-3.7dB = 0.3dBu = -1.9dBV=0.8V) for different scenario
DAC is the ADI-Pro fs R for all. (So when comparing black and red, we are comparing ADCs)

First straight from the DAC, +4dBu output range, with some digital attenuation (RME ADI-2 Pro fs R - new version)

Then with DAC set for +13dBu output range, with passive attenuation

Finally, with DAC set to +4dBu output range, full output, with a light passive attenuation

That illustrates several things, I think
1. ADC is working (slightly) better on "Pro fs R" version than on "Pro fs Non R" version
(That was actually why I was measuring this to begin with)

2. Using +13dBu to generate a signal close to 0dBu is less efficient than using the +4dBu range.

I guess this is true for the ADI-2 "Non Pro" fs too...



Notes:
1. I never "calibrate" the output.
So when you see in the signal generator "Output amplitude" = 1V, that means 0dBFS for the DAC, which is the full range (+4dBu or +13dBu in those examples).
2. Those measurements are all loopback, which accumulates noise and distortions from the DAC and the ADC (and from the passive attenuators where it's used). So 114.5dB SINAD here, while attenuated by 3 7dB, means that both DAC and ADC have SINAD better than that. How much better we can't tell.