Article: The Value Proposition In Computer Audio: Nuts, Bolts, and Building Blocks - Building a Home for Your Player Software

[bluesman]

View full article

[bluesman]

7 minutes ago, Middy said:

A nice introduction to the simplicity of computers..... So much to take in but thank you... when my head stops spinning ill re read it. Amazing..

 

Dave

Hmmm - now that I see it on the web, it's looking a bit larger than it did on my monitor  

 

I could have split it in half, e.g. propriertary vs open source.  But I was so far into it by the time I realized what a monster I was creating that it was easier to just finish it, move on, and remember the lesson.  The next piece takes the same approach to single board / micro computers for audio, but is lighter and easier to digest.

[bluesman]

9 hours ago, JJinPDX said:

Thank you for this amazing series of articles! 

 

Looking forward to the next one on SBCs. Just bought a RPi 4 to play with, mainly as a Roon bridge. I’ve been concerned that it might not provide what I’m hoping for, but they are so inexpensive why not give it a shot! 

 

Many, many thanks! 

 

John J

I think you’ll find it to be all you want and need. I run RB on a stock 4G Pi 4b in my living room system (SMSL SU8 into Prima Luna Prologue 5 driving Focal 726 towers) and it sounds fantastic! I haven’t rebooted in weeks, and the temp never gets above the low 40s C with a Flirc fanless case.  
 

I go into cases and cooling in a bit of detail in the next installment, but the one piece of info you need now is that a cool Pi will last for years in audio use - but if you let it overheat, it will probably die of a stroke in middle age.  You don’t need a fan to keep it comfortable, but you do need a good metal case like the Flircs that I prefer. I cite data on cases and cooling in the next piece, and the Flirc does the best of any passive case (& looks really nice).

 

You’ll probably never see it, but a thermometer icon will appear on your Pi’s GUI (if you’re using a video monitor) if the CPU temp hits 80C. At this point, it will throttle the CPU back to 3b speed to help cool it.

 

Thanks for the nice words! Enjoy your music.

[bluesman]

1 hour ago, Ben-M said:

That was A LOT of content about operating systems. 

 

I'm sure there are many other ones and I assume other people will mention ones they figure you missed, but I want to throw Snakeoil OS (https://www.snakeoil-os.net/) out there as another 100% audio dedicated Linux distro. And it has Roon and HQPlayer configurations now too.

 

I've always thought the lead developer Keith was a great guy and very focused on being an audiophile and making an audiophile OS.

 

Snakeoil is basically a bare bones Ubuntu server with a real time kernel. It leaves out the processes that aren’t needed for audio but that may affect it adversely (a controversial topic open to discussion elsewhere).  I’m sure it’s fine, based on extensive experience with many other Linux distros on dozens of boxes. But I find any benefits of a real time kernel for audio (playback only) to be somewhere between minimal and undetectable on good, modern hardware.  Multiple CPU cores and hyperthreading have largely eliminated these factors.

 

Even for recording, the only tangible benefit of a RTK over low latency versions (if there is any) comes when recording tracks alongside existing ones. Latency results in asynchrony between the monitored track(s) and the live one being added. This is compensated in good recording software, but the better choice is to eliminate it up front. There are adjustment settings in good DAWs to do this.

 

Theoretically, a real time kernel that prioritizes CPU calls in audio processing will reduce potential for any degradation of the bitstream, with allegedly better SQ resulting. I haven’t heard this myself, and I suspect that it would take a better system than I’ve ever had to demonstrate it if it’s real.

 

I do plan to try Snakeoil for RPi. It might benefit performance from the lower power versions (ZeroW and 3) and deserves a listen.

[bluesman]

5 hours ago, mentt said:

Audiolinux, Euphony truly works. On the same HW it truly sounds way better than optimized Windows 10 with Roon. Music sounds very natural and musical. Noticeably better than allo digi one signature powered by good power supply. This is the first time I enjoy using PC as transport component.

That’s great to hear, and your feelings are shared by many. My point about this example is only that there are dramatic interpretations on all sides of all such comparisons, and the superlatives used to describe each are pretty strong (e.g. “way better”).  The SQ gap between any two would have to be wide to go from “way better” on one side to “way better” on the other.
 

Given the close to equal opinion split between any two, I believe that these gaps are probably 90+% personal preference driven by confirmation bias, selection bias, etc and <10% real ordinal differences in SQ.  There are so many confounding factors that we can’t possibly control for them all, e.g. minor deviations from flat frequency response combined with nonlinear listener hearing sensitivity across the audible spectrum.

 

So I believe that listeners have definite and valid preferences and should use the systems they find most pleasing.  I just don’t believe that most of these differences are objectively as dramatic as the chosen descriptive terms suggest.

[bluesman]

1 hour ago, mentt said:

 

Well the last 3-10 % of SQ is usually the difference between enjoying the listening to music and not enjoying the music at all. And that is in the end the most significant difference...

You quoted me correctly but ignored what I said, which is that

 

"I believe that these gaps are probably 90+% personal preference driven by confirmation bias, selection bias, etc and <10% real ordinal differences in SQ."

 

I was only referring to the described differences in SQ between alternatives (the "gaps"), not SQ itself.  When one group of audiophiles describes the SQ of a component, system, etc of known high quality as "fabulous" and "heavenly" and another equally adept and experienced group says it's "horrible" and "unlistenable", there simply cannot be that much objective difference between the alternatives.  Had I chosen to shed all pretense of being PC, I'd have said that it was 50+% personal preference, 49+% semantic hyperbole, and SQ that's QNS.

 

If there were a system that truly reproduced and presented a recorded source exactly as it was performed, and if audiophiles were all equally able to both detect sonic differences and evaluate them totally without bias, almost everyone within a given budget would have the same system.  When a roughly equal number of audiophiles seem to prefer either of any two alternatives neither of which is perfect, the most logical conclusion is that the alternatives differ minimally and that listener-related factors are driving that decision rather than objective variance.

 

Parenthetically, I find it hard to understand how a music lover could "...not [enjoy] the music at all" because of SQ differences or deficiencies.  Most of us listen throughout the waking day on a variety of devices and systems that are suboptimal, e.g. smartphones, car systems, portable players, etc.  When SQ is marginal, most music lovers subconsciously apply "neural filters" that let us hear the music as it is despite sonic aberrations, so we can we can enjoy it even though reproduction is flawed.  Listen to a talented amateur string quartet play on student-quality instruments, or a concert in a venue sufficiently large &/or designed poorly enough to require sound reinforcement - the musical content is a joy despite its flawed presentation.  When you listen to the equipment, you hear the equipment.

[bluesman]

36 minutes ago, Jud said:

First, thanks for the very thorough review. With the enormous number of options even a review of this size must leave out a lot of information, but there is plenty enough here to be very useful.

Thanks for the kind words, Jud.  As you observe, there's so much more out there that it seemed both impossible and unnecessary to present anything beyond the few systems and instances that seem most useful and suitable for audiophiles.  Remember that most people were both frightened of and frightened away from Linux as recently as 5 to 8 years ago, so any distro that's harder or more intense to use than Windows or MacOS will be a hard sell.  I seem to recall a post by Chris some years back in which he expressed doubt that audiophiles would ever adopt Linux 😉

 

Even today, there can be stumbling blocks with Linux.  The most common are network file shares (which most often means Samba issues), USB and other bus issues (which are often driver issues), and Wifi.  But Ubuntu, Mint, and a few others are now as easy to use as Win and Mac

 

36 minutes ago, Jud said:

Both Xubuntu and Manjaro will run HQPlayer and, I assume, Roon

Only Roon server and Roon Bridge are available for Linux.  Server is only available for 64 bit architecture, which is fine with me since all current major distros are also 64 bit - but there are still 32 bit Linux users with older machines that won't run Roon server.  You also can't run Roon Bridge on a Pi Zero, but it's great on 3s and 4s.

[bluesman]

1 hour ago, fas42 said:

I agree with this ... when the SQ is 97% or so there, every annoying deficiency of the playback system keeps on nagging one;

So with tongue only halfway in cheek, please help me to understand this. On what scale does one measure SQ? Is it a linear function? What’s the unit of measure? With what do you measure it? And, most importantly, if you’re already at 100% (which must be the case, unless you’re either suffering mightily while using your own system or not listening at all), will you be using your current system forever?

[bluesman]

1 hour ago, mourip said:

I use Audiolinux in ramroot for my two Roon endpoints. On my server I have tried Windows 10 Pro, Windows 2012, Windows 2016, Windows 2019, and Audiolinux ramroot. On all of the Windows and Windows server implementations I used Audiophile optimizer which I highly recommend.

 

So far the Windows Server versions have all sounded the best, with Windows Server 2019 to be out ahead of all others to my ears. I love Audiolinux on my endpoints but found it dry and bright when used on my server.YMMV.

 

SQ is what you decide it is for your system, in your space and for your own ears... unless you have a spouse/partner and then it gets tricky! All of the elements of your system combine to produce it.

 

.

The hardware also matters.  Everything from the cooling, mechanical rigidity and vibration isolation of the case & parts to the array and arrangement of components inside the box to the quality and integrity of connections among them can affect SQ. I suspect that these factors could also affect the relative performance of different software in the same box.  And this is as true for the server as it is for the endpoints - basics matter.  Some computer layouts and parts combos may even be more sensitive to software than others.

 

As for the spousal factor, I can only offer thanks for a wife of 47 years who’s tolerated speakers bigger then she is, component racks in the living room, and wires all over the place despite never having listened to music at home by herself on anything more sophisticated than a radio or TV 😁

[bluesman]

3 hours ago, audiobomber said:

You don't need to know much of anything about operating systems to play music through a computer.

Right you are - as I said in the last piece in this series, "A Raspberry Pi 4 with 4G of RAM is an amazingly powerful little box that will run some great players from simple MPD to a full instance of JRMC - for $55 plus a power supply.  SQ is excellent, and it takes less than an hour from the time you walk in your front door with it to be playing music."  The piece before that one has a simple table with info offered to help uncertain audiophiles choose a player for the Pi.  It includes both player software running on named Linux distros and players that come with dedicated JEOS like your Volumio instance (which I reviewed, included, and use myself).

 

But even for those who, like you, are using simple little boxes that require little active management, knowledge is power.  I'm in your camp - I'm currently running music software of some kind (including Audacity and Ardour for live recording) on two Pi 3bs, two Pi 3b+s, two 4 gig Pi 4s, and a Zero W.  The 3B+ can't hold a performance candle to the Pi 4 (which I document in the next piece, which is on SBCs and includes links to performance testing of the Pi family). So you may someday find yourself wanting to upgrade, in which case you'll want to know something about software related problems in the 4 gig Pi 4.  Start with the fact that it won't access more than 3 of the 4 gigs of RAM right now because of software bugs (at least on Raspbian).  And this affects USB connectivity, which came as a huge surprise to me and does not affect 1 and 2 gig Pi 4s.  The workaround is to limit RAM use to 3k in one of the configuration files - but I want the RAM I paid for 😉 

 

There are a few patches out there to try to fix this, but it remains a problem and I have it - Roon Bridge drops and reconnects it as a zone in a cycle lasting roughly a minute per drop & add, and it appears to be because the USB connection to the DAC is being lost.  I don't know yet if this bug affects the 4 regardless of OS, so I'm testing it with several to find out.  So as long as your Volumio instance runs fine on your 3b+, you don't need to know anything else about your operating system.

 

Remember too that your use of computers for audio is only one of many possible roles they can serve.  If your needs or preferences suggest that an x86 or other big box is the best home for your computer solution (or you want to use an older computer you already have but can no longer run its legacy OS), some kind of guide or information for decision support may be very helpful in choosing your new music platform - and that's why I'm writing these.

[bluesman]

You’ll read more about temp control & overheating in the next chapter.  And there’s more on this in the following one (being prepared now), which is about hot rodding SBCs for audio with a focus on the RPi. Cooling is essential if you overclock, but a good fanless case like the Flirc (my favorite) is all you need for a stock Pi 4.  Placed in an area with good ventilation at an ambient temp below 25C (about 80F), even a stock plastic case should be fine for most audiophile use of a stock 4. I strongly recommend using heat sinks though - they’re tiny, cheap, and effective. The life of Pi is shortened by running often at temps close to the throttling threshold.
 

The stock 4 throttles CPU speed down to that of your 3b+ when its temp hits 80C.  I’ve pushed one hard with live multitrack recording and real time monitoring, and it peaked at 73C in the standard plastic case. A Flirc brings that down to about 60C, and a $7 fan cooled case lowers it to a max of 43C no matter how hard I flog it.

 

Playback of DSD files with DSP and other added CPU stresses may push temp too high to ignore. If so, this would justify a case with good cooling (active or passive), but I haven’t yet run these scenarios and will provide my findings when I do.

[bluesman]

3 hours ago, audiobomber said:

Not sure if you watched the video I linked. He said the Pi 4 sounds inferior to a 3 B+ for audio. Several comments below agreed with his assessment, which is the opposite of your recommendation.

I've seen and read a lot of Hans B's output, and I simply don't agree with much (maybe even most) of what he hears and describes.  FWIW, his self-described background and qualifications to offer the opinions he holds are, to me, more than a bit specious:  "Before starting his carreer [sic] as a professional tech journalist, he sold hifi and recording equipment for ten years."  You'd think a "professional tech journalist" (even a self-described one) could spell correctly and/or proofread what he posts, which is not nit picking - if I paid him to write something for me, I'd expect it to be perfect on delivery and so (I hope) would you.  That directly quoted misspelling from his main website has wrankled me since the first time I saw it, and his other errors simply compound that.  If he's that unconcerned about detail and accuracy on his website (especially in his bio), why would we expect more accuracy in his audio reviewing? 

 

I'm also more than a bit disappointed that he virtually never provides clear descriptions of what he hears or objective testing to support his contentions.  The presence of test equipment behind him in his pictures is misleading if he's not going to provide any results.  You're obviously of a different opinion, and that's fine - there's room for all of us, especially if we're civil in our expressions of disagreement.

 

I'm not alone in my opinion about the Pi - in fact, I'm far from alone, and there is objective testing to support what I believe is the excellent SQ of a well set up Raspberry Pi 3 or 4.  For example, read this Pi 3b review with test data from Archimago.  Further, he's apparently unfamiliar with the USB bug in 4G Pi 4s right now, and it definitely affects audio.  I tested a few operating systems on a 4Gig Pi 4 to see if the USB problem is ubiquitous, and it's not.  Ropieee does not seem to display it - I've had no disconnects or sonic aberrations at all after 72 hours of connection.  Roon repeatedly drops and reconnects the Pi USB zone when running Bridge on Raspbian Buster.....but not Stretch, which works and sounds fine.  So there's an inherent problem in the 4 that is known to the development team, who are promising a patch "soon".  I only wish Hans had actually provided some technical info so we could know what he actually tested - was it Raspbian Buster, Stretch, or something else?  If I missed it, please let us know.

 

Hans B offers 95+% unsubstantiated opinion, and I simply disagree with a lot of it (as do many others).

[bluesman]

9 hours ago, BluRay444 said:

Amazon, search:

Jun-Electron for Raspberry Pi 4 Model B Case, Dual Cooling Fan, Enclosure Aluminum Alloy Case with Heatsink Pillar

 

I've seen others similar, but passive only:

Geekworm Raspberry Pi 4 Armor Case, Raspberry Pi 4 Computer Model B Armor Aluminum Alloy Passive Cooling Case Compatible with Raspberry Pi 4 Model B Only.  Virtually the same case available from The Pi Hut for $15

My favorite is the Kupton case with fan for $6.95 (with a 3A wall wart similar to the “official” Pi PS but with a switch in the line - it’s fine if you interrupt the power through USB and power your DAC directly & independently).  It comes with 4 little heat sinks and keeps an overclocked (2.3) 4 gig Pi 4 at an average of about 40C while recording live stereo or playing 2 ch DSD128 - the highest temp I’ve seen was a brief period at 43C.

[bluesman]

4 hours ago, MeMa2010 said:

First, thanks to bluesman for an excellent read!
However, I must admit that most of it went above my head. I found this article, because I am looking for the ideal setup to combine my Kef LS50W speakers with a new Samsung smart TV ("The Frame"). I currently have all my music on an external usb hard drive, and I have been using JRiver MC for some years and very much like that software. I thus read this article to find out if I should use a computer to connect these devices, and if so which one, or if I should buy some other device (the speakers are great at reproducing sound, but they do leave quite a bit to be desired regarding their streaming capability, so I was thinking that if some type of standard pc solution cannot solve my needs, than perhaps I need a proper server, which could be something like an Innuos mkIII?).

I am still in as much doubt now as I was before reading this otherwise highly informative article, so If anyone here would be so kind as to help me with some advice as to how I can best solve my doubts and connect my devices for the optimal compromise between sound quality and convenience, I truly would be most grateful.

My new tv has not arrived yet, and at the moment I am connecting my laptop directly to the speakers via usb, but I know it is far from the ideal solution.

And thank you - I really appreciate the kind words.  The "Value Proposition in Computer Audio" series is focused on pure audiophile use, so it looks in depth at critical issues for music listening (e.g. sound quality, music library management, album art display, tagging, external data search and retrieval), ease of use (e.g. downloading, installing, configuring, listening),  skill & effort levels required, and choosing a computer platform for your music software.  To this end, each article has a table or other summary suggesting the pros and cons of commonly used platforms for different music-related needs. 

 

The introductory article was a general discussion of how computer based audio systems turn performance into playback. It's process based - for example, here's the front end article suggests some players and music management programs for different wants and needs:

 

FOR	CONSIDER	FOR ITS
Musicians	Audacious, Sayonara	Flexibility, effects like control over playback speed & pitch
Jacket junkies	Jajuk	Comprehensive web sourced art & info displays
Techies on budget	Foobar2000	Full features if you’re willing to work a bit to get them going
Casual listeners who don’t want to have to fiddle with it	GogglesMM, Gauyadeque, QMMP, Rhythmbox	General layout, usability, stability, simplicity
Web radio listeners & other internet streamers (from web servers, not yours)	Cantata, Foobar2000, Kodi, Lollypop, Moode, QMMP, Sayonara	Excellent setup, display and selection of web radio stations & streams;
Streaming from your own server	Foobar2000, MPD clients	Ability to access your own music server remotely; Cloud services make this less necessary; takes some config work;
Those with huge music libraries	GmusicBrowser, MediaMonkey, QuodLibet	Ability to digest, display, and manage lots of files
Great tag management	MusicBee, QuodLibet	Tagging capabilities & flexibility
A simple system you can make with little work and less $	RuneAudio, Volumio on a Raspberry Pi	Great value in simplicity, reliability, sound quality, etc;
A simple player you can drop onto your PC	Daphile, MusicBee	Simplicity and ease of installation; versatility – play from computer’s audio out, drive USB DAC/amp etc; great & easy intro to computer audio
Most of what you get from JRMC, Roon etc without the cost	Foobar2000	Amazing flexibility and continued development over many years; it takes some work to learn about plugins etc, and configuration isn’t always easy or intuitive – but you can get fantastic sound from almost any source with just a bit of work

 

The series is organized to parse the various wants and needs into categories, to simplify the search for good solutions. Here's the first set of questions asked:

• What computer will you use?

  • One you already have

  • A new one you plan to buy or build for multiple uses, one of which will be audio

  • A new one you plan to buy or build as a dedicated audio player

• How complex do you want your system to be?

  • One box solution (player, server, etc)

  • Computer front end with NAS or other remote server

  • Other

• What are your player access needs?

  • None – player to DAC to audio system at one location like the old days

  • Remote control only on LAN with mobile app

  • LAN – multiple endpoints / renderers on a home network

  • WAN – access to home server to stream remotely

• What program sources will you access?

  • Local music files only

  • Web radio

  • Other internet streaming sources

  • Video material

• What kinds of music files will you play?

  • mp3

  • High resolution FLACs

  • DSD

  • MQA

  • Multichannel

  • Other

• What kind of computer will you use?

  • x86 etc

  • ARM based, SBC

  • Other

• What operating system will you use?

• Do you tend to stick with something you like for a long time or change around a lot?

Your inquiry seems to address a comprehensive media hub, which is a different kettle of fish that we're not frying in this series  But you can take the same approach I used to hone in on good answers to your questions.  The Frame looks like a cool device - but it comes with a lot of functionality that duplicates what you may already have, e.g. voice control, web and mobile control apps.  It has its own "assistant" (named Bixby) but can also be integrated with both Alexa and Google Assistant.  If you don't have a home hub already, the Samsung SmartThings Hub offers integration among your Samsung devices and can help you create a "smart home" if that's something you want. But you have to know what you want before you can figure out how to best get it.  So you have to define your wants and needs.  Here are some questions to get you started:

• What do you want to be able to do when you're set up and running?
  • listen to recorded music
    • files on your own device(s) and/or networked storage
    • internet radio
    • streaming services
  • watch videos (which can also have different sources requiring different equipment & functionality)
  • have unified control over media selection and playback, "smart home" functions like lights, thermostats, etc
    • through a home hub
    • through an "assistant" like Alexa or Google Home
    • through a web and mobile app
  • other - there are many, many possible answers to this question & only you know what they are
• What do you mean by "...[using] a computer to connect these devices"?
  • to which devices do you refer?
    • just the speakers and the TV
    • your current laptop, the speakers, and the TV
    • more or other devices
  • what needs connecting - data sources, media outputs, other?
  • do you have or want to set up a LAN, WLAN, or both?
    • do you want a networked media system that will let you play audio and video through the new TV?
• Are you sticking with USB storage for your files or considering networked storage?
• What do you mean by "combine my Kef LS50W speakers with a new Samsung smart TV"?
  • Do you want TV sound to come from your KEFs but be controlled (volume etc) by your TV?
  • Do you want to integrate your KEFs into a multichannel home theater setup?
  • Do you want to play multiple media from networked storage through your TV? HT?
  • Do you want to use JRMC as a true media center for your network or only for music?
• What are your future plans for all this?
  • Are you building a system today for the long term with no plans to upgrade in the foreseeable future?
  • Are you building a platform on which to expand your network and/or media system(s) over time?
• What are you doing about backing up your media files?
• How big a chunk of your resources (time, money, space, structural mods like electrical lines / outlets / conditioning, etc) will you dedicate to this?
• How much assistance will you need in designing your system, selecting the components, setting it all up, etc?

This list could go on for days.  So you have to decide exactly what you want to have when you're done, which functions and factors are essential for your happiness, and what compromises you're wiling to make.  We have 4 Samsung "smart TVs" and each one has a different IQ.  I was amazed to learn (after I bought it) that our 2018 55" TV does not have the firmware to integrate with our Samsung SmartThings hub.  I'm no expert on smart homes and networked multimedia systems, but I've been a GE-certified Lean/6 Sigma master black belt for over a decade and I know a fair amount about process and system engineering.  Despite this, I failed to choose a new TV that was compatible with our desires.  If you don't define your needs up front, you'll never know if you met them.

 

Good luck!!

[bluesman]

3 hours ago, audiobomber said:

IME, technical qualifications have no bearing on someone's ability to judge sound quality. You do realize that English is Hans B's second language, right? I would have liked to hear your experience with SQ of the Pi 4 vs. Pi 3 rather than three paragraphs of Hans B flames.

 

Greater computing power is not necessarily an advantage for music reproduction, and in fact can be the opposite. Measurements have limited value in assessing SQ. I expected the Pi 4 to be superior to a Pi 3 for playing music, but that is not what I've read thus far, except in your article. Below are a couple of expert opinions.

Yes, I'm well aware of Hans' origins.  I'm not flaming him at all - I'm expressing the opinion that the value of what he offers seems far less to me than it is to you, and I'm explaining why.  It's very hard to believe that his command of English is less than excellent if he's done everything he put in his bio, e.g. having written "for a large number of magazines in the UK".  Further, it doesn't matter if English is his second language or if he doesn't speak it at all.  What matters is his level of attention to accuracy and detail (which, I hope you will agree, is critical for a tech writer).  He could hire a translator, an editor, a bilingual web designer, etc if he can't write up his material perfectly himself.  As a long time professional tech editor, he should be well aware of the rigors of publishing technical material and the many ways of achieving excellence in his field of expertise.  The errors in his content and presentation suggest to me that he's not as concerned about detail as he should be (or isn't as much of an authority as he claims to be).  I also generally disagree with what he says he hears. This is not denigration - many people disagree with Robert Parker's taste in wine and Roger Ebert's movie reviews, too.

 

Hans was obviously either unaware of the current USB problem in Pi 4s or chose to ignore it.  He's in the same boat as the two experts you cite, neither of whom expresses awareness of the Pi 4 USB issue.  And if you read further down Dimdim's thread in which you found that quote, you'll find this from an otherwise anonymous contributor named Derek:

 

"Well, it’s been a few days (and nights) of listening to the RPI4 installed in a PCB – previously occupied by a 3B – and powered by the same linear 1A supply as powered the 3B. Both running Moode. Both I2S. So, a swap of the 3B for the 4.
Think I prefer the 4 in this configuration – linear PS and I2S out. Seems to have a hair more resolution, slightly better bass definition and a ‘feeling’ of more coherence. It’s not huge, it’s slight but I’m going to stick with the 4 in the unit."

 

There are also many rave reviews of the Pi 4's SQ using USB, e.g. this one by David Snyder from September 2019. His bottom line for a Pi 4 driving a few different USB DACs (all with separate power supplies) is "Well, it’s early in my evaluation, but it sounds great so far. Like the Raspberry Pi 3 Model B+, the RPi4 has 5 GHz Wi-Fi and 802.11ac support, so streaming DSD256 and 32-bit, 768 kHz PCM are [sic] no problem. The background is inky black on quality recordings, leading to impressive dynamics."  I agree with this. Sadly, neither Mr Snyder nor the authors of many other such web posts include which OS is being used. Sadly, neither Hans B nor Snyder tells us if the Pi 4 evaluated is a 1G, 2G or 4G RAM model - and this matters because the USB issue is largely a problem of the 4G RAM variant.

 

Higher CPU speed may actually affect SQ negatively for simple stereo playback, based on some experiments by Archimago and a few others. But CPU-intensive processes like DSP, transcoding, and sampling rate changes make a CPU work hard for a living. So pumping out DoP, DSD256 and other demanding playback modes can even affect SQ of some pretty hefty x86 devices when combined with DSP etc.  So you have to balance what you want to play and how with your choices of hardware and software to achieve the best compromise for your wants and needs.

 

The next piece in this series is an overview and general discussion of small boxes / SBCs with only my summary impressions of the SQ of individual devices.  I'm currently working on the one to follow that, which is focused on the Pi from stock ZeroW, 3b+ and 4 to a hotrod 4 with overclocked CPU and GPU.  This will include more detail and links to files recorded, edited, and converted from format to format entirely on the Pi4. 

[bluesman]

5 hours ago, MeMa2010 said:

Onmy main reason for getting a screen/TV is for managing JRiver. I never actually watch TV, and I haven't even had one since I moved out from my parents house some twenty years ago, nor do have I have any interest in a smart home (I would actually even prefer not having that, especially not having any microphones in the house, as that strikes me as being somewhat creepy). The reason for choosing "The Frame" is that it seems to be the aesthetically least intrusive screen that my wife and I have been able to find, since it can be put directly on the wall and almost looks like a work of art when not in use. We probably will get to watch a few movies on it too sometime on our external DVD drive or online, but probably not more than one or two a year, so its main purpose will be to enable the use of JRiver for music without having to open up the laptop.

The Frame has a built-in media player. You could simply plug your USB drive into it and play music without JRMC, using your KEFs as the TV speakers. Or you could put JRMC on your i3 computer, use the Frame as your monitor via HDMI, and drive your KEFs with either the computer or the TV. You’d need a remote control if you don’t want to leave a wireless keyboard & mouse out.  Any inexpensive Android phone or tablet with a browser will work fine. I’ve bought 2 in the last year for under $50 USD on sale.

 

Enjoy!,

[bluesman]

13 hours ago, MeMa2010 said:

The reason for choosing "The Frame" is that it seems to be the aesthetically least intrusive screen that my wife and I have been able to find, since it can be put directly on the wall and almost looks like a work of art when not in use. We probably will get to watch a few movies on it too sometime on our external DVD drive or online, but probably not more than one or two a year, so its main purpose will be to enable the use of JRiver for music without having to open up the laptop.

Another simple alternative is to get yourself a Raspberry Pi 4. You can use its HDMI port to drive the TV, connect your USB drive to it, and power your speakers with either USB or Bluetooth from the RPi or from your new TV. JRMC runs well on the 4, although you’d have to pay for that version separately even though you already bought the one on your laptop. An inexpensive tablet would work fine as a remote for that too - but you need a WLAN to use a mobile device as a remote in any system you set up. There is a way to set up a a Raspberry Pi as a WiFi hub, but I think you’re better off using a simple ac wireless router.

 

JRMC on a Pi does not do quite as much as it does on an x86 PC. But for a simple 2 channel audio system, it’s quite fine.

[bluesman]

15 hours ago, JJinPDX said:

Well, LOL! It took me a whole day to get my Pi4 to make music via usb to my W4S re-clocker and finally to my Bryston BDA-2 DAC. But, I am now happily playing Mahler's 2nd. It took me that long because I did all kinds of things wrong and did them wrong at least three times, then changed my mind about the OS a few times, and on and on. But I am very happy with the result. The only question I have is, is ALSA as good as WASPI or ASIO or what-have-you. But that discussion would be for another thread. Just know that I got it to work, and am looking forward to the next installment detailing SBCs. Thank you once again!

 

John J

Congratulations and welcome to the club - you’re now an official Pi head!  Yes, ALSA is as good, with direct kernel-to-hardware communication and the drivers built into the kernel. But in the Linux sound platform, ALSA sits “below” Pulse and JACK, which are roughly the Linux equivalents of WASAPI and ASIO.  And, as in Windows, you don’t have to use them - but they’re there (if installed, as not all distros load both on installation) to help if you want / need them.

 

Although you can use ALSA without Pulse, most distros install it if there’s any audio software at all in them. Pulse does not replace ALSA, it helps you manage it.

 

JACK is a fancy patch panel with which you can “connect” the inputs and outputs of your Linux audio system, including MIDI and audio instruments and other sources, for complex recording and monitoring as well as mix down, mastering etc. I use it with Ardour for live recording, but you don’t need it just for listening to your music.

 

There are other audio packages you’ll see but not need, like Carla. Linux audio can be complex if you let it or if you need that level of sophistication. But most audiophiles do not. Have fun!

 

PS: what OS and music management system did you finally use?

[bluesman]

1 hour ago, bluesman said:

PS: what OS and music management system did you finally use?

PPS: Is your Pi the 1, 2 or 4 gig model?

[bluesman]

1 hour ago, JJinPDX said:

RPi 4 Model B/4GB. Probably overkill just for Raspian Lite and the Roon Bridge, but I have it hooked up to the TV and will eventually load Kobi so I can play all my ripped DVD's that are stored on the NAS, along with my music. I must mention that where I have my system cannot be reached by ethernet or coax cabling, which irritates me no end. So everything is by wifi. I'm using the 5 GHz band and so far there have been no hiccups with this. The highest I can go with the Bryston is 24/192, but that plays with ease. I cannot do DSD, so have no experience over wifi with that.

I have a Pi4 in our living room running Bridge via 5GHz Wifi and it does DSD128 (actually DoP into a 2nd gen SMSL SU-8) just fine. If you're not already doing so, you might consider a good case for your Pi.  I have a Flirc passive case on the living room Pi and a fan cooled case on the hot rod with which I'm doing the work for the article on modding SBCs for audio (which will follow the next one, already completed & carrying more info on the Pi and other SBCs).

 

If you were unaware of it, there's a bug in the 4 gig Pi 4b that limits RAM access - we're not able to use the full 4 gigs with the current firmware.  This model also has intermittent USB problems that go away if you limit memory access to 3 gigs in one of the configuration files.  The development team is working on a fix, and I'm hopeful that it'll be available soon.  Roon drops and reconnects one of my two 4s running Bridge on Raspbian Buster over a roughly regular cycle of about 30 to 60 seconds - but I don't have this problem with Ropieee.  I'm about to try with DietPi and Bridge to see if it's peculiar to Raspbian.

[bluesman]

7 hours ago, JJinPDX said:

I did not know about the memory limitation. I did try to expand the use of RAM to its max, and apparently it did. Using "free -h" I see that I'm at 3.8Gi, but only using 202Mi with 3.5Gi free. The unit has been playing now for over 6 hours with absolutely no hiccups at all.

The USB and RAM problems with the 4GB Pi 4 are inconsistent - I have a USB problem on one of mine but not the others, and only with Raspbian Buster (even with the latest firmware). The problem is apparently in DMA (direct memory access) in 64 bit systems - here's a link to the technical description of the problem, and here's a link to the rapsberrypi.org forum thread about it.  I don't understand how you can access a full 4G of RAM with Raspbian Buster and maintain good USB connectivity, but this is a strange problem and I hope Canonical comes out with the fix soon.

 

Here's a link to the official Ubuntu communication about it. In a nutshell, the Ubuntu team says:

• "official support [from the Ubuntu team] for this board is currently limited to the 1GB and 2GB versions. Due to a kernel bug, USB ports are not supported out of the box in the official arm64 image on the 4GB RAM version. Kernel fixes have been identified by Canonical engineers. We are currently testing these fixes extensively. We will push updates within weeks, following successful test completion.  In the meantime, developers can use a temporary workaround to enable USB on the 4GB RAM version. The temporary solution will consist in editing the file /boot/firmware/usercfg.txt to limit RAM to 3GB"

I'm using my problematic 4GB Pi 4 only as a test mule for now. Both the 3GB limit workaround on Raspbian and Ropieee work fine, so listening in our living room zone is uninterrupted until a proper fix is pushed by Canonical.

[bluesman]

1 hour ago, JJinPDX said:

I don't know if this is a problem or not, but I'm recording a temp of 68C using vcgencmd measure_temp. Seems high to me. 

 

Still no hiccups though. Might try DietPi for grins and giggles. 

68C is normal for a Pi 4 in a generic plastic case and in many metal ones with no heat transfer mechanism with ambient temps between 70 and 75F.  The onboard throttling trigger is 80C, so 68 is “safe” according to Canonical and many Pi experts.  I suspect it does shorten component life, though.  
 

A passive cooling case like the Flirc has an integral platform inside that’s joined to the CPU by a heat transfer pad - Flirc brought my first 4 down from a high of 73C while recording live music to wav files with Audacity, monitoring via software playthrough, to about 50. A fan cooled case keeps it even further down - I haven’t gone above 43 with the same recording setup and the same sources (multitracking my own instruments) in either of two plastic cases with fans.
 

Routine 2 channel Redbook flacs cruise along at 35-36C with fan cooling and about 40-41C in a Flirc in a 70F room.

 

DietPi is cool, but it’s a bit much to configure if used only for audio - there are many software packages available in the setup, and even if you only want Roon bridge, you have to run through the setup screens anyway.  I like Ropieee because it’s just a Roon bridge on a JEOS, and there’s nothing else with which to deal.

[bluesman]

18 hours ago, JJinPDX said:

Ropieee is having trouble with USB 2.0 out to a Music Streamer II DAC I had laying around. Pops and clicks, although it did start out okay. Not sure why it suddenly started misbehaving. It recognizes the DAC through Roon just fine. Will re-flash the 4-gig SD that I put it on and try again. I will also report the issue to the Ropieee folks on Roon, but thought I'd let you know. Went back to the Raspian Lite and no problems at all. 

The 4 gig Pi 4 is obviously still a work in progress. I'm reminded of the early life of the Porsche 911 and how continued increases in engine size and power pushed components to and beyond their limits.  Yes, it's another loose analogy - but as displacement got closer to 3 liters than the original 2, little things like head studs started failing.  And factory "patches" like case savers and Dilivar studs were only partially effective.

 

Like air cooled 911s, the poor little Pi may have reached the limits of safe and reliable performance without costly and exotic work-arounds - and that's how reliable and inexpensive high performance items turn into finicky and expensive ones.  Let's keep trying to make these the best they can be, recognizing that we're probably just biding time until the next advance in SBC design.

[bluesman]

19 hours ago, JJinPDX said:

Just a follow up...  With the Flirc case running Bridge on Raspian Lite for many, many hours, highest temps, both CPU and GPU, 38C. Ambient temp 68F. No hiccups at all. 

 

- JJ 

Great stuff!  Here’s another teaser for the article I’m preparing right now - my task yesterday was to install, set up and gain more experience with OpenMediaVault on Raspbian Buster Lite on a Pi 3b+.  Today I’m adding it to a multi-Pi music system for live recording, ripping, and listening.  It’s up to 3 so far - one as a dedicated audio workstation, one for mixing, mastering, file conversion, and listening, plus the NAS to keep all files out of USB traffic and archive every bit.

 

The reason for separate recording and monitoring devices is that a 3b+ can’t process both a source signal and real time monitoring of it without stuttering, popping and dropping out. A 4gig Pi 4 handles this better for single track live recording and for ripping, but the price has to be paid for latency. Fortunately, Audacity has an excellent correction function, although it’s a bit tedious to dial in. It offsets the input by 123 msec on mine after setup, which lets me lay down multiple tracks with excellent time alignment. 
 

Once I figure out how to make it work with a brace of 3b pluses that I already own, I’ll try to distill it down to a portable recording station with two Pi 4s.  I’m waiting for complete resolution of the problems with the 4 gig version before buying any more.