All Things Digital Audio

Thanks for the offer David. I am going to have to pass on it right now. I have a few too many things going on. I have read about Diretta previously and think your implementation sounds intriguing.

Hi Scott,

The Baetis architecture makes sense to me and is what I've been advocating for Roon subscribers for quite some time now. Diretta takes this "two piece format" and advances it to three separate stages, as I described in my pervious post. Here's a bit more expansion on that idea:

Roon's Blueprint for Superior Sound: Server and Endpoint Separation

At the heart of Roon's philosophy for achieving high-fidelity sound is the separation of the Roon Core (the server) and the Roon Output (the endpoint). This two-tier architecture is fundamental to minimizing electrical noise and processing demands at the most critical point in the audio chain: the connection to your Digital-to-Analog Converter (DAC).

• The Roon Core: The Heavy Lifter. The Core is the brain of your Roon system. It manages your music library, handles audio processing (like DSP, volume leveling, and format conversions), and streams the ready-to-play audio stream over the network. By design, this is a computationally intensive role. For the best performance, the Core should be a powerful machine, but importantly, it can and should be located away from your listening room to isolate its inherent electrical noise.

• The Roon Endpoint: The Clean Player. The endpoint's sole responsibility is to receive the pristine audio stream from the Core and deliver it to your DAC. In a properly configured Roon system, the endpoint does minimal processing. This "lightweight" approach is crucial because less processing means less electrical noise generated by the endpoint's hardware, which can otherwise interfere with the sensitive analog circuitry of your DAC. This separation ensures that the noisy server operations do not pollute the delicate audio signal path.

From what you described Baetis is now doing something similar. However, Diretta takes things in a different direction:

Diretta: Conquering Low-Frequency Noise

While Roon's architecture significantly improves sound quality, there's another subtle, yet impactful, source of sonic degradation: low-frequency electrical noise generated by the endpoint itself. Even high-end DACs, with their sophisticated power supply rejection, can be susceptible to this type of interference. This is where the Diretta protocol offers a groundbreaking solution.

Diretta's core principle is to minimize fluctuations in the endpoint's CPU and network processing load. Standard network protocols often deliver audio data in intermittent bursts, causing spikes in the endpoint's power consumption. These spikes create low-frequency noise that can subtly veil audio detail and dynamics.

Diretta employs a "Host" and "Target" model. The Diretta Host sends audio data to the Diretta Target (your new, specialized endpoint) in a continuous and exceptionally steady stream of tiny packets. This keeps the Target's processing load remarkably constant, thereby preventing the generation of the low-frequency noise that plagues typical network endpoints. The result is a blacker background, improved micro-dynamics, and a more natural, lifelike presentation of the music.

The Ultimate Three-Tier Architecture: Roon + Diretta

By integrating Diretta into a Roon system, we evolve from Roon's recommended two-tier architecture to a state-of-the-art three-tier design, further isolating and purifying the audio signal:

1. Tier 1: Roon Core. Your powerful server, located anywhere on your network, manages your library and prepares the audio stream.
2. Tier 2: Diretta Host. A lightweight device on your network receives the audio stream from the Roon Core. Its job is to then transmit this audio to the Diretta Target using the specialized, constant-stream Diretta protocol.
3. Tier 3: Diretta Target. This is your new, ultra-low-noise endpoint connected directly to your DAC. It receives the perfectly paced data stream from the Diretta Host, doing the absolute minimum amount of work required to pass the audio to the DAC.

This three-tier model represents a paradigm shift in digital audio playback. It takes Roon's excellent foundation and adds a crucial final stage of signal purification, directly addressing a source of noise that other systems neglect.

Leapfrogging the Competition

High-end, all-in-one music servers from manufacturers like Innuos, Lumin, and Aurender have built their reputations on creating low-noise hardware. They often employ high-quality power supplies, low-power CPUs, and chassis designed to minimize electrical interference. While these are commendable and effective approaches, they are fundamentally limited by their single-box or two-box designs. The processing and server functionalities, even when partitioned, are still in close proximity to the final audio output stage.

The Roon and Diretta three-tier architecture offers a more elegant and arguably more effective solution by achieving a greater degree of functional and physical separation. It doesn't just shield components from each other; it fundamentally changes the nature of the data transmission to the DAC to be as quiet as possible. This modular and specialized approach allows for a level of sonic performance that can leapfrog even the most sophisticated and expensive proprietary servers, offering audiophiles a path to truly top-tier digital sound.

I realize this sounds kind-of salsey. I was skeptical myself, but this solution seems to be pretty unique at the moment in how it addresses the cause of processing and network noise at the source rather than mitigating it afterwards.

The crazy thing is that, for folks who are a little handy with computers, this solution can be built for under $300. Once assembled, it's easy to operate and has been reliable, at least for me and the few other folks I know who are trying it. I'd love to help Atlanta Audio Club members achieve the same results.

David,

Another great post from you. The offer truly sounds terrific. I read your description of the Diretta Host and did some investigation online. The concept makes total sense to me.

That said, I need to add that I have paid the folks at Baetis to upgrade my equipment to a two piece format which uses the same functionality i.e. music delivery on one box and Roon management on a different box. I'm told that some of their customers already have this equipment and love it - for many of the reasons you have mentioned.

Thanks so much for contributing to this subject. Would you let us know of any further thoughts you have on the matter.

Scott

Hello AAC Friends,

Thank you to everyone—Kyle, Scott, Jeff, William, and Larry—for the fantastic replies. Your diverse experiences with Roon, Aurender, local files, and streaming have been incredibly insightful and confirm what I've been working on. I promised some "pretty exciting" news, and after reading your feedback, I'm thrilled to share a discovery that has fundamentally changed my perspective on digital playback.

Many of us share a common goal: we're trying to get computer or network audio to sound as good as a top-tier SACD player. Some of you, like William, are meticulously experimenting with components to extract better performance from local ALAC files. Others, like Larry, are looking for a reliable, high-quality path forward as older systems become obsolete. The solution, as I’ve found, isn’t just in a better box, but in a better architecture.

For years, I’ve been trying to get the message out about Roon's distributed architecture. The philosophy of separating the "heavy lifting" Roon Core from a quiet, lightweight "Endpoint" is the correct one. It’s designed to keep the processing noise of the server away from your sensitive DAC. However, there is another level of performance possible.

My Discovery: A Three-Tier Architecture with Diretta

While Roon's model is excellent, the endpoint itself still generates subtle, low-frequency electrical noise from its own CPU and network activity. Because of the low-frequency nature, this noise evades the DAC's power supply noise suppression filters. While effective at high frequencies (in the 1 MHz range), they are ineffective at the low frequencies generated by bursty network traffic. This is where a protocol called Diretta comes in.

Diretta works on a "Host" and "Target" model. The Host transmits audio to the Target (the new endpoint at your DAC) in an exceptionally steady stream of tiny packets. This keeps the endpoint's processing load remarkably constant, preventing the very noise that can veil detail and dynamics. It also physically and electrically isolates the network audio transport from your noisy home network.

By integrating this into a Roon system, we create a state-of-the-art three-tier design:

1. Tier 1: Roon Core: Your existing server, located anywhere on your network, doing the hard work.
2. Tier 2: Diretta Host: A new, small device on your network that receives the stream from Roon and uses the special Diretta protocol to send it forward.
3. Tier 3: Diretta Target: The final, ultra-low-noise endpoint connected to your DAC, receiving a perfectly paced data stream and doing the absolute minimum work necessary.

This modular approach achieves a profound level of functional and physical separation, leapfrogging the performance of many expensive, all-in-one proprietary servers. The result is a dead-black background, stunning micro-dynamics, and a natural, lifelike presentation. This is the most impactful discovery I've made in digital playback since async USB almost 20 years ago.

The AnCaolas Link: My Proof of Concept and an Offer for the Club

I've implemented this three-tier model in a proof of concept I call the AnCaolas Link. The feedback from folks here in Arizona for whom I've demonstrated this approach has been overwhelmingly positive. Even if you are happy with your digital frontend, there's another level of sound quality you haven't heard yet. I didn't think it was possible myself, but here we are.

This is a passion project for me, and I want to share it with the club. It's about having a direct, positive impact on the hobby we all love. To that end, I have two offers:

• Build Your Own: For those who enjoy a fun project, I am happy to personally assist you in building your own two-box Diretta Host/Target solution. The cost for all the necessary parts is under $300.
• I'll Build It for You: If you don't have time for DIY projects and simply want a reliable "appliance" that just works, I will build a set for you. You would only need to cover the cost of the parts. Note: I get nothing out of this except the satisfaction of helping you to experience the surprising sound quality gains that I have in my own systems.

This is the answer for Roon users looking to take their system to the absolute next level and for anyone who has struggled to get network audio to match their best disc spinner. This becomes the logical final step for the audiophile who wants the peace of mind that the digital link to their prized DAC is as perfect as it can be—and without spending thousands of dollars to get there.

Let me know your thoughts. I'm happy to answer any questions. I'd also be happy to meet with interested folks over a Zoom call or even do a presentation for the club to discuss this project further.

-- David

David, I recall watching a video of a presentation you gave to the audio club many years ago. As a newer member I have been drinking from the water hose of info for the past year or so. I have just barely heard the word Roon mentioned and really don't know much about it.

I have ripped many of my CD collection (and a few bootleg live LPs) down to my computer over the years. My CD collection now has over 3600 titles. I have used the Microsoft Windows software Media Player as the vehicle to rip my CDs over to my computer. It has the ability to look up the artist, track info and artwork for most of the stuff I have. I occasionally have to go hunt for this or create the track listings but that is maybe 1 out of 25 or so. I started ripping music many years ago and used the .mp3 format only as I could easily transport it to a portable player for my walks or airplane rides. Personally, I am totally happy with the sound of an .mp3 file although I know there are much better -LOSSLESS formats. Since I own all of my physical media still (except the bootleg LPs) I could easily rip them to a different format if I wish. WIth my Windows 10 workstation support coming to a close in Fall 2015, I may be looking a new options for a music server and management of my vast media library. Like Scott Peterkin I also have a large library of cassette tapes of rare live concerts that I should probably convert to digital as well. I have used the Audacity software and that was used to rip about a dozen bootleg live LPs several years ago before I sold them for a pretty penny. I guess I should have kept them given the rapid rise in value of vinyl again.

I have an Amazon Unlimited account now and can use it to stream newly released music. It allows me to stream in HIGH QUALITY audio, whatever that means. It sounds very good to me. I also configured my home computer to be recognized by my Sony Blu Ray player and Sony XBR TV so that it can stream music from my hard disc over to that system. I got it to work a couple times, but it seems to be problematic working over WiFi. I also have a Roku device that can stream music as well.

I look forward to hearing more about future developments.

Great replies, William, Jeff, Scott, and Kyle. Just a few more and I'll be ready to break the news I have for you.

I guess I would be in the "A" camp but don't think Roon does a good job with my local files. Most of my files are ALAC as I was originally using iTunes and either Bitperfect or Audirvana for playback. With the debacle of the Apple Music rollout around a decade ago, I decided to find a new solution in Roon. Soon afterwards my Metric Halo dac died and my digital system was reborn using a mac mini as the Roon server with an attached hard drive for storage. Music was sent via ethernet to an Allo USBbridge that then connected to a Chord Qutest. The USBbridge and Qutest were powered by a single Allo Shanti power supply. This sounded great for Qobuz and I began "upgrading" my local files in Roon to use the Qobuz versions instead.

Fast forward a few years and I got the itch to try HQplayer and upsampling with the Qutest. I liked the results but the USBbridge couldn't handle 705/768khz without pops and clicks occurring. Added the SRC DX USB to dual BNC converter which helped the 705 Khz upsampling. Replacing an older cat 5 cable with a cat 6 cable helped some more, but the problem persisted. That's when the rpi4 stepped in to replace the USBbridge. It is powered by the same Shanti supply. I think it sounds great streaming Qobuz through Roon but local ALAC files still sound underwhelming. I never did a direct head to head with the USBbridge but I don't miss it. BTW, I use Ropiee as my Rpi software.

A fancier streamer may handle local ALAC files better than my Roon setup but I have been too busy moving to Atlanta the past 2 years to try one out. I do think having the bridge separate from the Roon server is a very good idea. Many of the people complaining about Roon online have their Roon server connected directly to their dac or they try to use wifi for transmission.

Libraries can be unwieldy. Another option, and one which works for me is to keep digital files on an Aurender server using multiple 4TB solid state drives. I use two of them in a N10 and am able to maintain a current library of >19,500 albums using mostly WAV & DSF files. 

These files are all searchable with associated cover art down to the track level using Aurender's conductor app that works on both Apple & Android devices. 

I also use another music server from Cambridge Audio, using their stream magic app, with a removable portable hard drive for files I wish to audition. This allows me to swap files back and forth with the Aurender using my laptop P.C. Both servers are connected using separate inputs on my dCS DAC.

As to analogue, I keep a library of around 2000 vinyl lp's listed and categorized on the Collectorz app on my P.C. This allows displaying actual cover art, track listing plus additional user generated categories for sorting files. Collectorz has a similar product for video that I use for my 4K, Blu-ray & DVD's.

Still looking for similar software for my reel to reel tapes.

Jeff

Thanks for opening up this Audio Time Capsule. Very relevant to me today as I struggle with my audio library. The 6k+ collection of CDs remain largely on the shelf. Fortunately they have all been transferred to a music library and are now accessed by Roon. That is, not including the CD pile which is waiting to be played which I have temporarily put off while I deal with digitizing the portion of my cassette library which cannot be duplicated elsewhere. It should come as no surprise that Roon is my organizational lifeline. For me, due to the limitations of storage capacity in my home, the era of collecting physical media is coming to an end.

I should add that I believe I have you, David, to thank for recommending the M2Tech Joplin MkII for Analog to Digital conversion. After years of looking I found one on e-bay (mislabelled so it just sat unnoticed at half price of the other units). After purchasing it the seller offered the companion linear power supply which I quickly accepted. BTW whoever decided to make the on/off button on these units look exactly like a small piece of hardware won't receive any note of thanks from me.

Still ahead for conversion to digital with access via Roon is my vinyl collection. Does the music sound better remaining on vinyl - maybe but I simply can't downsize homes (still years away) until I reduce the amount of vinyl I have. Honestly - if there is in fact a sacrifice in sound quality I'll have to accept it.

Anyone reading this might say - if you haven't listened to the cassettes or vinyl in a decade why keep the audio? So - here is a partial list of what I have been archiving from cassette: (1) A radio program called American Popular Song with composer/songwriter Alec Wilder (he actually wrote "the" book on the subject) with a different musical guest each week (2) Fresh Air interviews of Stephen Sondheim and others (3) Radio events - live concerts and performances (4) Hard to find recordings - The McClain Family Band (apparently they only made one recording??) and a recording of Aaron Copland in rehearsal with orchestra conducting Appalachian Spring (included with the LP as a one time 45 rpm bonus extra).

I should also mention that I have been asked to digitize cassette tapes recorded on soundboards at concerts for singer/songwriters. There are over three hundred of these tapes to be digitized. I will return the tapes on jump drives and CDs to the tape owner - per his request. For myself, I will no doubt put the audio into my digital library and access it via Roon. This conversion was a tall order due to the amount of equipment and software which had to be pulled together. Without AI it would have been much harder.

Back to Roon. What I really like about this product is how easily I believe it can be replaced if someone comes along with a better audio mouse trap. The audio files are all in WAV and can be played by almost any software. Unlike cassettes (I should have mentioned that I have found some that although unplayed for decades are degrading to the point of not being usable) or CDs which "lock up your audio." Roon is simply a messenger - one that I am happy to have in my audio system until it is surpassed by a newer generation of music management.

[A]

Love the versatility, but wish there was a way to integrate Spotify. I have a pretty robust Roon network with several endpoints that range from RPi's (a blend of dietpi & ropieee) Roon Ready, and Roon Tested devices.

Looking forward to the HOT new News from you David!

Thanks,

Kyle Stephens

I can't believe this post was from almost six years ago. A lot has changed in that time, not just in audio, but the world.

Still, this is an audio club, so I'll stay on topic. If you are a Roon subscriber and use it in your primary (digital) playback system, I'd like to know which of the following statements describes you best (A, B, C, or D):

A - I never thought digital audio could sound so good!

B - Other solutions (like Innous, Aurender, Baetis, Lumin, JPlay, Audirvana) sound better than Roon, but I keep using Roon for the user interface and music exploration features.

C - I quit using Roon because it just does not sound very good to me. I went back to physical media or another solution.

D - What is Roon?

I'll share more (something pretty exciting, actually) once I have responses from a number of you. Thanks.

Hello AAC Friends!

My editor at Dagogo.com (the guy who also organizes the California Audio Show) asked me to write a series of articles on audio streaming. Here's a link to the first installment. Feel free to ping me directly or add comments/questions at the bottom of the article. Thanks for having a look.  :)

https://www.dagogo.com/advancing-audio-streaming-part-1-raspberry-pi-4-usb-network-audio-transport/

-- David
   678-231-0568

P.S.
   I'll add more links to this thread as additional articles are published.