Berkeley Alpha DAC Reference Series 2 MQA

[The Sandman]

With the transport, the Alpha USB is a moot point because there is of course no USB to begin with.

Ah, now I get it.

[Aldog]

Mike. Roon will pass a MQA files that can be unfolded to their full extent if you have a MQA DAC. That is the way I get my files to my Meridian 808v6. In your Tidal App you have to check Pass Thru Mode and it will disable software decoding and pass the MQA signal for the DAC to handle.

Hey guys...new to the shark and just updated my Ref2 Friday evening. The improvement to regular PCM is pretty impressive but for some reason the DAC is not recognizing MQA content aka "mqa" not being displayed.

I have tried my standard set-up through Roon (Roon Core on Mac Mini > ultrarendu > Alpha USB) and Tidal App directly (USB from both OSX & Windows 10 laptop > Alpha USB) to no avail.


Interestingly the latter displays 192 but no MQA while Roon won't go higher than 48. All DSP, volume leveling and other "enhancements" have been disabled. Any insights or add'l things I should try. Thanks, Al

[joeinid]

Welcome to the forum Aldog, thank you for joining.

[still-one]

Hey guys...new to the shark and just updated my Ref2 Friday evening. The improvement to regular PCM is pretty impressive but for some reason the DAC is not recognizing MQA content aka "mqa" not being displayed.

I have tried my standard set-up through Roon (Roon Core on Mac Mini > ultrarendu > Alpha USB) and Tidal App directly (USB from both OSX & Windows 10 laptop > Alpha USB) to no avail.


Interestingly the latter displays 192 but no MQA while Roon won't go higher than 48. All DSP, volume leveling and other "enhancements" have been disabled. Any insights or add'l things I should try. Thanks, Al

Do you have Tidal set up properly?
Under Settings ---> Streaming Do you have HiFi/Master checked?

Then did you point your curser next to Built In Output option near the bottom where a gear will pop up. Click on the gear and make sure you have MQA Passthru checked. (On my device I also have checked Use Exclusive Mode, but not sure for your device)

[Aldog]

Thanks Jim. I had been using the settings you suggested but in playing with a few different variations was able to get it work by unchecking MQA passthrough and but leaving Exclusive Mode engaged. Who knew?

I guess this makes sense as it's my understanding the Ref2 MQA is a renderer only that requires software decoding on the front end. This would also explain why it isn't working with Roon - unless there is a workaround I'm not aware of.

[audio.bill]

I believe Roon is still in the process of implementing MQA Core decoding in their software, so until that functionality becomes active Roon won't be able to provide MQA decoding in conjunction with the Berkeley Ref2 MQA.

[wklie]

Thanks Jim. I had been using the settings you suggested but in playing with a few different variations was able to get it work by unchecking MQA passthrough and but leaving Exclusive Mode engaged. Who knew?

I guess this makes sense as it's my understanding the Ref2 MQA is a renderer only that requires software decoding on the front end. This would also explain why it isn't working with Roon - unless there is a workaround I'm not aware of.

Berkeley Ref2 is a MQA Renderer, so it requires something that performs MQA Core decoding in front of it, that includes Tidal desktop app (Passthrough Off, Exclusive On), Audirvana, Lumin U1 (beta firmware).

(The only case Tidal desktop app Passthrough should be set to On is for MQA Full Decoder DAC products, not for MQA Renderer products.)

If you're a Roon user, you will need to wait for Roon to provide MQA Core decoding in the future, as audio.bill mentioned. (Or use a Lumin U1 (beta firmware)).

For the distinction between MQA Full Decoder (case D) and MQA Renderer (case C), please read:
https://www.computeraudiophile.com/c...for-civilians/

[Aldog]

Thanks guys. I appreciate the insight and info. At least for us Roon users we can still enjoy the significant improvement to standard PCM from this update while we wait for full MQA implementation.

[stevebythebay]

Greetings one and all. Just received my firmware from the BAD boys. Had trouble trying to get the update to "take". Seems my MacMini-dCS Network Bridge-Ref 2 hung at Ld_. So, after running this past Mr. Ritter at Berkeley he was puzzled though he suggested that playback via Roon might be the source of the problem. He suggested I try keeping it simple. So I installed an old copy of JRiver on the MacMini, ran USB (rather than Ethernet to my Cisco smart switch which in turn is wired to the dCS) to a previously used Berkeley Alpha USB and then my AES/EBU cable into the Ref. 2. That worked perfectly.

I don't yet have a Tidal license, as I'm awaiting both dCS firmware and Roon to support MQA. However, as I knew the Berkeley firmware would be a plus for PCM, I jumped at the opportunity to get it. I've been listening for the past few hours and it is a significant upgrade on its own. Not only more liquid (less strident in some ways) but seems to "unravel" the harmonic structure from top to bottom - supple and an exceptional improvement. Whoa, listening to a harp and acoustic guitars, go Segovia.

[wklie]

Correct! Aurender is considering it (or working it). But no promises as they are in the feasibility phase. Lumin U1 will have it soon.

Lumin U1 is now MQA certified. Lumin U1 can output the required MQA Core signal via AES (or USB) to Berkeley Alpha Reference 2 MQA Renderer, to fully enable the MQA feature of REF2.

In this article http://www.theabsolutesound.com/arti...ent-3530562059
you can see Berkeley's comment on MQA: (edited/combined from multiple posts)

It's my assumption that everyone posting opinions on MQA here is doing so in good faith. Unfortunately, few individuals or organizations have the level of knowledge and methods necessary to make an objective assessment of MQA's potential. We are fortunate to have that capability as a result of the extensive R&D effort into analyzing human perception and audio quality undertaken by our previous company, Pacific Microsonics, Inc. developer of the HDCD process.

We agree that "time-smear" reducing apodizing filters can have mixed effects, but when applied to files created by a typical A/D with awful transient pre-ringing the trade-off of much better spatial information vs. some timbral grunge is usually worthwhile. However, those kinds of “fix-up” tools that are optional parts of MQA aren’t what really interests us.
Our most important due diligence was thoroughly analyzing the entire analog to analog MQA chain using proprietary in-house methods and tools. The result was that MQA came within spitting distance of what 192kHz, 24-bit PCM is capable of using optimum A/D and D/A conversion filtering.

That level of quality, by the way, hardly exists in the wild and few have heard it. Some RR HRx releases that were never edited can get close assuming you use the right D/A. What more people have heard that sounds the closest is a live microphone feed.

All in all, we felt it was a very impressive result and made us decide to support MQA. Without a standard like MQA keeping the “windows” clean, conversion filtering at both ends will be all over the map with very few combinations ever approaching an optimum.

While I don't expect to change the opinion of those who are convinced MQA is of no value, I felt it was my responsibility to honestly report our finding that MQA is of great enough value to both support and incorporate in our products.

Sincerely, Michael Ritter, Berkeley Audio Design, LLC

The most common types of low-pass filters used in A/D converters have a characteristic called pre-ringing. Pre-ringing generates artificial sounds in a recording ahead of (before) natural transient events in the signal that excite the pre-ringing. Please understand that by "transient event" we don't just mean a sharp transient like a drum hit or plucked string. All of the natural sounds we hear in life contain micro-transients, the amplitude and timing of which convey both timbre and spatial information to the cochlea and brain. When these natural micro-transients are passed through a filter that has pre-ringing, sounds are generated that don't occur in nature and the cochlea and brain don't know what to make of them. The subjective result is that spatial information is diminished or lost and subtle timbre information is obscured or altered. This type of time-domain distortion is probably the single greatest weakness of typical PCM digital recordings.

in theory 192 kHz, 24 bit PCM is all that is needed IF both the A/D and D/A conversion filters are an optimum conjugate system. If optimum PCM conversion filtering requirements were widely enough understood and if the AES were a powerful enough organization I could envision an AES standard that A/D and D/A conversion products would need to meet to be accepted. Unfortunately, that isn't remotely the case in today's world. Unless there is an identifiable standard that gets the physics right and all the stakeholders from artists to recording engineers to distribution entities to equipment manufacturers to end users think will benefit them (including making money for some), PCM conversion filtering is going to remain a grab bag of random A/D and D/A pairings, most of which are pretty bad. MQA is the only such standard we are aware of anywhere on the horizon. So we support it. BTW, probably a major reason high resolution audio "isn't making it in the marketplace" is that almost all of it is sub-optimum and squanders much of the inherent potential of 4X, 24-bit PCM. Have you ever heard an entire record/replay chain that was essentially indistinguishable from an excellent live microphone feed of a huge orchestral choir work? I have and it's both astonishing and entirely doable with the knowledge we have today. But it's never going to be available to most listeners without a marketplace driven standard that gets both the A/D and D/A conversion filtering right.

[stevebythebay]

Your linked page seems not to show Ritter’s explicit comments. Am I missing something? By the way, when speaking with him recently, he expressed his quite favorable impressions of the Lumin U1.

[wklie]

It is required to press "Load more comments" (perhaps more than once), then manually find m_ritter. It's quite troublesome to find comments in that web page, so I just copied and pasted his words in my last post.

[bibo01]

You also have order by date

[mauidan]

https://www.computeraudiophile.com/c...a-update-r678/