PREVIEW: RME ADI-2 Pro FS AD/DA Converter

I. Prologue

For those who have followed along on the blog, you may recall that this blog started with some arguments I had with folks on an audiophile forum around the audibility of high bitrate MP3. Back in those days (err... late 2012), there were all kinds of claims made by quite a few hobbyists that they could "easily" differentiate lossless FLAC from 320kbps MP3. I'm sure there are still many in the audiophile forums who hold this view although I think things have softened about the magnitude of differentiability (I think this shift has changed with high-res audio as well).

That disagreement was enough to push me to put out a blind test, to start looking into what I could do to help further my own understanding and awareness around audio hardware. The articles on this blog basically have been the culmination of that pursuit in hopes that the ideas and tests have been useful for others also on this journey looking for some clarity, typically found with more objective analysis.

Objective testing requires disciplined procedures and tools. Methods to reduce variables so that we can have reasonable "apples-to-apples" comparisons and reduce or eliminate psychological biases when we make decisions and search out facts beyond opinions colored by idiosyncratic preferences. Whether it's using an ABX tool, asking a partner/spouse/family/friend/neighbor to change something without our knowledge when listening, or measurement devices - letting the tool demonstrate changes - I believe we can find answers to uncertainties or prove claims. I personally believe objective testing is not only something "nice to have" with reviews, but an essential part of developing insight into the devices being tested and our own perceptual and cognitive limitations.

That's a long intro which brings us to today's preview of a new tool. :-)

When it comes to using an ADC for measurements, over the years, I've gradually upgraded starting with my old Creative E-MU 0404USB from 2012, to the Focusrite Forte in 2016, and now, let's start with a look and listen to the RME ADI-2 Pro FS ADC/DAC. The aim has been that each step brings with it more accuracy for the measurements and this third iteration of the measurement hardware should bring with it opportunities to explore further and continue the process of finding clarity in a hobby that for too long IMO has been filled just with mere opinions - or even worse perpetuation of myths. (Remember, nothing wrong with opinions... But let's make sure it's grounded in objectivity!)

Local Audio Store Visits: Liquid Sound, Vancouver. (And engagement with high-end audio dealerships...)

Well, it is summer and today I thought I'd post something a little "lighter", "softer" and I think more typical of audiophile blogs :-).

I was thinking the other day, I'm fortunate to be living in Vancouver where despite the decrease in brick & mortar hi-fi audio stores over the decades, there are still a number of stores in town that have listening rooms and show off some high quality equipment. In fact, I live less than 10 minutes away from the Headphone Bar (article on Inner Fidelity a few weeks ago). Over the years, I've also talked about local places like Hi-Fi Centre and Commercial Electronics - both about 30 minutes away. If I head in a somewhat different direction from home, further west, we get to Liquid Sound along West 10th Ave.

Obviously, based on my writings, tests and listening, I have a "more objective" take on the audiophile hobby than the "mainstream". I have not seen any large polls but I suspect that the number of audiophiles who appreciate objective analysis might be rather significant.

There is something to be said about knowing about the local dealers and having the opportunity to visit, see, feel, and hear the latest on offer out there. Likewise, I think the local dealers need to check the "pulse" of the audiophile hobby and appreciate the demographic characteristics especially as the typical Baby Boomer audiophiles age. This IMO includes engaging the "more objective" folks who might be more than a little turned off by obvious hype and pseudoscience.

DEMO / MUSINGS: Let's listen to some jitter simulations with sideband distortions...

A couple weeks ago, we started getting into the topic of jitter and the concept of whether jitter is audible and at what level. As I had expressed at that time, my belief based on experience with the equipment I have looked at / listened to is that with almost any reasonable modern day digital audio device, the likelihood that one would hear sampling jitter effects is extremely unlikely. No need for crazy expensive cables that claim jitter improvements. No need for high-priced servers (like this), expensive streamers, or "de-jitter"/"reclock"/"regen" devices. But one of course does want to have a good DAC with excellent jitter rejection, and these days, competent asynchronous USB devices almost universally will achieve excellent results by reducing jitter from the interface (remember, the older S/PDIF digital interfaces typically perform worse than modern USB or ethernet even though newer devices like the Oppo UDP-205 perform excellently with any of the inputs).

The reason I say this comes not just from measurements and my own listening to devices with different severities of sampling jitter, but also experimentation over the years in simulating the distortions introduced by jitter.

As I mentioned last time, with Yamamoto2002-san's WWAudioFilter, we can easily use DSP to introduce fixed amounts of sinusoidal periodic jitter to "bake in" the kinds of sideband anomalies often found with devices that suffer from jitter. For today's post, what I want to do is provide some test files you can use to actually hear what severe jitter distortions with sideband anomalies sound like. Think of this post as similar to one years ago when I demonstrated what poor USB cables sound like.

Furthermore, coming out of this article, I hope the audiophile reader can appreciate the magnitude of jitter that is necessary in order for the effect to become audible. In so doing, I hope it will help us appreciate the results from the J-Test FFT's I publish here and also when you look at measurements elsewhere (like on Stereophile).

"MQA-CD x UHQCD" Listening Test by Agitater.

[Editor's Note: As you may have read in the last few months, there is a new variety of "MQA-CDs" released into the wild. Here in the West, we have seen the new release by Steve Reich Pulse/Quartet contain MQA encoding (playback FFT commented on here). In Japan, a series of MQA-CDs have made their way into public hands from Warner, called "MQA x UHQCD" (UHQCD stands for Ultimate HiQuality CD) which is basically a combination of MQA encoding + "better material" on what is still basically a standard "compatible" CD with 16/44.1 PCM data at premium prices. I guess this kind of thing still interests Japanese audiophiles!?

Techmoan did a review of these which IMO missed the mark as the reviewer clearly does not understand the limitations of MQA itself and believes it really is a "high resolution format" which is IMO false as previously discussed. He also used a glitching portion of Brothers In Arms as a gauge that the MQA-CD sounds "better" through the Pro-Ject Pre Box S2 rather than normal playback (clearly the MQA decoding and filtering changed the output amplitude on the Box - the MQA playback sounded louder).

Techmoan's video did not really compare actual CDs already on sale for years with these new MQA/UHQCDs using higher quality equipment - he just used a computer setup and headphones, obviously having trouble getting things working. To "fix" this situation, here's Agitater and his buddies on Steve Hoffman's Forum! With his permission, I've posted in full his detailed listening sessions conducted with audiophile friends on very high quality systems. Slight editing with headings added for the blog format. A beautiful write-up that just had to be shared and not get lost within a message forum!]

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Asked and answered . . . Here are my music listening group's listening notes and conclusions about the following four UHQ/MQA-CD releases. The albums are, in order below Moanin' by Art Blakey & The Jazz Messengers, Blind Faith the eponymous album by the early supergroup Blind Faith, Getz/Gilberto by the studio trio of Stan Getz, Joao Gilberto and Antonio Carlos Jobim, and Aja by Steely Dan.

Here's the DAC. It's a MyTek Brooklyn DAC+ with fully switchable MQA filter. Note the little, blue MQA indicator light. It was used in all of the listening sessions in a variety of systems, and acquitted itself brilliantly. Note that one of many peeves related to MQA DAC implementations is that the MQA filter can't be turned off and is applied to all streams including non-MQA (standard?) CDs. MyTek made its licensing deal with MQA, obviously, but in the process has retained its own superb filters. That's my Benchmark DAC3 HGC (unused in these listening sessions) below the Brooklyn DAC+.