Saturday, November 2, 2019

Digital audio without tears

In earlier posts I described systems I was using for listening to lossless (FLAC) digital audio. A lot has changed in my various audio setups that would take too long to explain, but I wanted to update you on a really nice lowish-cost transport for DACs and integrated audio devices with S/PDIF or AES digital inputs that I strongly recommend. The ingredients (most used in a previous setup):

  1. Pi 3 SBC
  2. PiTouch 7" touchscreen
  3. SmartiPi stand
  4. Pi2AES audio shield
  5. Power supply for Pi2AES
  6. Pi 2 Design supplies (5) with a straight barrel adapter that is too long for the stand (3), but this elbow adapter fits (thanks to Michael Kelly @ Pi 2 Design).
  7. Whatever miniUSB 5V power supply you have around to power the PiTouch (I'm using an otherwise idle Chromecast power supply)
  8. moOde Audio Linux-based digital music software
I set this up on my home network, which allowed me to configure moOde through a Web browser on my laptop, but I run it at work disconnected from the network, with all the music on an SSD. If your system is always networked, I'd skip (2), (3), and (6) and buy the nice Pi2AES case from Pi 2 Design instead. The same hardware can be used with other Linux-based audio distributions. I used to favor piCorePlayer, and I still prefer its lean, fast UI, but it has become unusable for non-networked systems, unfortunately.

For those of you who have USB DACs or integrated amps, I've heard good things about the Allo USBridge Signature, which can also be bought as a complete box with a Pi and pre-installed software.

I've used quite a few more expensive transports in different configurations, with different DACs and downstream audio chains. Pi2AES is definitely competitive with many times more expensive transports, if you are willing to do the hardware and software legwork, and I suspect Allo USBridge Signature will be too.

Pictures of the Pi2AES-based transport feeding a nice Soekris dac1541 sign-magnitude R-2R DAC from Denmark followed by the now discontinued HP-1 headphone amp from Neurochrome in Canada.



Tuesday, May 28, 2019

Digital audio findings

It's a long story that I won't give in detail, but 6 years ago I started to explore digital lossless music, initially CD rips but increasingly digital downloads. My music interests are mainly contemporary jazz, modern classical, early music, Baroque, West Africa, Mediterranean, Middle East. I went through a lot of gear and setups since. I learned a lot, too much to summarize, but here are a few findings:

  • First question is why lossless rather than MP3 or AAC? Simply, it can sound better for some material (plucked strings especially) with the right downstream gear.
  • How do you get music into that form? If you have CDs, you re-rip them. I use XLD on my Mac. If you want to stream, you can use lossless Tidal or Qobuz (which is what I use). Finally, there are several lossless download vendors: ProStudioMasters, HDtracks, 7digital, eClassical, Presto Classical, and best of all because more money goes to the artists, Bandcamp for independent artists and labels. Most of my recent music is from Bandcamp.
  • How do you play it? You need a means to move bits from local storage or streaming sources to whatever turns bits into analog waveforms in your system. Many options there, from simple Apple or Sonos setups to integrated receivers from companies like NAD, Naim, or Hegel (owned gear from all of them), to dedicated digital transports connected to separate DACs, preamps, and amps.
  • You can use your phone or laptop as a transport, but it is also possible to use a variety of single-purpose devices for that. Here's what I assembled to use at work. Again, one can go crazy on digital transports, to stratospheric prices that make no sense to me. I do own a relatively pricey Metrum Ambre transport for my fancy headphone system(s) at home, but one can do well in the just-digital-audio transport front for much less, such as the Allo USBridge I have for my speaker system.
  • For quite a while, I was having a very good time with a single-purpose CuBox running Volumio, reading tracks from a home NAS (Synology) playing to a Schiit Bifrost Multibit DAC and a Schiit Jotunheim headphone amp for my home headphone and then work systems until I gave it to my daughter. People I trust claim that you can spend a lot less, either from Schiit or from vendors like AudioQuest for a very reasonable sound quality. The AudioQuest devices are nicely portable and work easily off your laptop or phone.
  • Schiit Audio has by far the best quality/price ratio that I know of for DACs and headphone amps. I've never tried their preamps, and speaker amps, but I suspect they win there too. They are also responsive, don't take themselves too seriously, and respond well to nice customer inquiries.
  • If you share living space with someone, or if you have close neighbors, headphone listening has got really good with the right headphones. I have only listened closely to a small number of different headphones, mostly rather expensive (>$1K), so I have no recommendations for anything below $500. At work, I use MrSpeakers ├ćon Closed, which work well for the sources and relatively laidback music I like for work.
  • It is hard for me to recommend speaker systems because I've heard way too few different ones in the last decade. I can say that for a small(ish) room, a pair of KEF LS50s with a sufficiently brawny amp (the LS50s are rather inefficient) give outstanding clarity and dynamics (LS50s are now mostly sold in a wireless, built-in amp version that I've not heard so I can't comment on). In my current larger living room, my earlier LS50s were replaced by KEF Reference 1s on stands, with a really brawny Hegel integrated amp, but those choices involved a bunch of other factors as well as a lot of listening at a couple of SF dealers. The Hegel integrated can take bits directly into its built-in DAC, which is fine but a bit too polite for my taste. Instead, I use a Schiit Yggdrasil DAC with some experimental hardware (don't ask) that allows it to get outstanding quality from a cheap Allo USBridge transport.
  • How do I get bits to my home systems? I've landed on Roon, which does the best job among alternatives to manage my eclectic local and streamed music collection and send the bits reliably to the two systems I listen on at home (speakers in the living room, headphones in the study). I run the Roon server on a fanless Intel NUC with Ubuntu Server 18.04, mounting its music from a Synology NAS.
  • You don't really want to go there: 

Monday, May 27, 2019

Dennis Bray's "Wetware"

Just finished reading Wetware, which I had owned for a while and started reading a couple times while traveling but misplaced both times, so I had to go back to the beginning. I don't agree with everything Bray says, and in the 8 years since he published the book, a lot happened both in computing and in biology. But I recommend Wetware to anyone who is puzzled about the similarities and differences between living things and computers. Three quotes that connected:
Neural networks can cope with large amounts of information, supplied as written text, facial features, industrial processes, and so on. They can recognize restricted sets of patterns better than we can. But what they do is the tapping of a tin drum compared with the symphony orchestra of natural environments.
Such coupling of environmental parameters through internal circuits allows a cell to predict future events. These circuits contain, implicitly, the probability of certain life-changing events.
If the detailed chemistry of the cell is simply the outcome of a historical ragbag of ad hoc interactions, then it will be no more predictable than the weather.