Monday, July 16, 2018

Raspberry Pi 3B+


The FM tuner has been a de rigeur music source in my audio system. Between the dwindling quality of FM broadcasts and proliferation of internet radio and music streaming apps like Pandora, Spotify, Tidal etc., I had to jump the bandwagon with my first generation iPad mini.

But as I delved into how to get the best sound from the internet, I realized that I could improve upon the iPad mini > USB DAC set up for not much $$s.  I've seen Blogs and YouTube videos on how the Raspberry Pi 3B+ (henceforth, RPi3B+), a 40 something dollar single board computer, can be configured as a hi-fi music player.

 A discussion of the RPi3B+'s sonic merits in the Joe-list initiated by a long-time audio DIYer, Larry Moore, was pivotal in my decision to try it. He recommended using the RPi3B+ with an I2S Allo Boss DACmoOde 4.1 + a linear power supply. Since I already had a couple of USB DACs, I just opted for the cheapest RPi3B+ bundle with a 5V/2.5A SMPS (switched-mode power supply), a molded transparent acrylic case and a couple of 16GB micro SD cards from Amazon.

The software for the RPi3B+ is contained in a micro SD card, which is inserted in the bottom mounted front slot. At the back is an ethernet port + 4 USB ports which can be loaded with USB thumb drives filled with music files and/or connected to an outboard DAC. On the right side, there's a mini USB for 5V power, an HDMI port and a 3.5mm below hi-fi grade audio out. 😞 To the left is a 40 pin GPIO header where an I2S S/PDIF device or DAC can be attached, which supposedly offers even better sound due to less jitter.  

 Once the software is loaded and configured the RPi3B+ will be operating "headless" (no monitor or touch screen). All functions are accessed and operated via a web browser on an iOS/Android device or laptop.

moOde 4.1

moOde GUI
Installing moOde 4.1 was not an easy task - not for me, at least. I had to bring the TV near the router to function as an HDMI monitor and plug a USB keyboard on the RPi3B+ to type commands which reminded me of WordStar word processing on an IBM XT/AT in the 80s. After two trials using the EZ install process and valuable assistance from the good guys at Hi-Fi Haven, my moOde 4.1 build was a success. 

The only glitch I had with moOde 4.1 is that Airplay doesn't work with the following DACs via USB: AQ Dragonfly Black, XtremPro X1 and Topping D30. So far I can only get moOde 4.1 Airplay to work with the Xiang Sheng DAC 01A below. I'm hoping that an update will address this issue. 


Volumio

Volumio GUI
After the moOde 4.1 initiation, installing Volumio was a breeze. The software is downloaded as a file"etched" on a 16GB micro SD card and then set up for Wi-Fi connection. No MS-DOS style typing required. Everything went smoothly even for a not-too-tech-savvy computer user like me. There were no issues with Airplay connection, regardless of which DAC was connected to the USB port. The choice of internet FM radio stations is at par with moOde 4.1 and there's a "plug-in" for YouTube. There's also support for Spotify subscribers. Since I only have a Spotify free membership, I "Airplay" from an iPad.

Sound

I wouldn't have known that the software itself can influence the sound in computer audio if I didn't embark on a Raspberry Pi journey. The more complicated set up procedure and USB > DAC issues notwithstanding, moOde 4.1 rewards the listener with deeper and punchier low frequencies, crisper high frequencies and more lucid midrange. Volumio sounds as if the leading edge of transients are slightly rounded off. The difference is actually quite subtle and only discernible after extended listening to both platforms.

According to MikeyFresh, a moderator at HiFi Haven who helped me a lot with the moOde install, "Moode is a very lean distribution, perhaps that's why it can sound better, it runs super efficiently and thus taxes the RPi3's CPU and RAM very little, which in turn produces less EMI/RFI to contaminate the signal." 

iPad mini as controller, RPi3B+ and Topping D30 DAC
I'd hate to bid adios to my beloved Scott LT110B and Dyna FM-3 tube tuners, but the RPi 3B+ is getting more air time nowadays. 

!!!STOP PRESS!!!

I initially considered the cheaper Hifiberry Digi+ Pro, but based on the positive reports I've read on the internet from RPi users, I took the plunge and got the more expensive Allo Digione S/PDIF HAT (aka Hardware Attached on Top) instead. A layer of electronic hash was removed by this I2S device and took the sound quality to another level = more analog, less digital. 








Sunday, July 1, 2018

Lafayette SK98 Reunion

 
Many years ago, I wrote about vintage Japanese drivers. From that survey, the 8" Lafayette SK98 aka Pioneer PIM8L full range driver emerged as a favorite due to its vivid midrange, balanced by respectable high and low frequency extension. Thinking that I could easily find replacements, I eventually unloaded both pairs to friends who didn't have the budget for Altec 755As

Lafayette SK98s in Altec 618 clones
Over 10 years have elapsed and I am happily reunited with a pair of SK98s, courtesy of my friend at Junkyard Jukebox. He believed that his treasured pair in Altec 618 clone cabinets should be in the JE Labs collection.

 Welcome back old buddy and thanks J-Rob!




Saturday, June 16, 2018

Ortofon SPU #1S and the Enigmatic Spherical Stylus


Garrard 301 + Ortofon RMG309 + SPU Classic GME

It seems like yesterday when my SETUP friends Joel, Nonong and William gifted me with an Ortofon SPU Classic GME cartridge for helping them get rid of the upgrade syndrome afflicting their high-end audio sensibilities back in the mid 90s. Within the same time frame, I was frequently talking shop with Sound Practices editor and publisher, Joe Roberts, regarding my Homebrewer article. At some point, the conversation segued to the virtues of the spherical or conical stylus based on the research done by Reto Luigi Andreoli (published in German by Christian Rintelen in Hi-Fi Scene Schweiz). Looking back, and at the risk of sounding ungrateful to my friends, would the humbler Classic GM have been a more appropriate gift? 😇


In the process of hunting for an original SPU with conical stylus, I instead landed three Denon classics - a ca. late 80s DL103, DL103S and DL103C1- for the price of a then brand new DL103R. Compared to a regular DL103, the DL103S is sweet and most extended in the high frequencies but least dynamic, the DL103R most detailed. The DL103C1 emerged as my favorite for combining all the virtues of the aforementioned models. These are very competent MC cartridges, which, along with the SPU GME, have been invaluable tools in voicing my audio system through the years. However, none of them could match the vivid midrange presence of the SPU.

Meanwhile, my spherical SPU hunting got sidetracked by Monaural playback and Retro Cool Tonearms and Cartridges.

Ortofon SPU Classic GME

In the intervening years, I had been fortunate to listen to higher-end Ortofon SPU models in familiar systems. Inasmuch as the SPU Royal, 85th Anniversary, Meister and Synergy offered better detail retrieval and extension in the frequency extremes to satisfy contemporary audiophile standards, I was never convinced that they were presenting a tonally more accurate sound overall.

Ortofon SPU#1S

After over 20 years, the idea of owning a spherical stylus-equipped SPU still haunted me. Fortunately, Ortofon introduced two entry level SPUs in 2016. I bit the bullet and ordered the cheaper SPU#1S with a bonded spherical stylus last year and couldn't be happier. Even if the #1S has slightly less top end extension than the Classic GME, the midrange is even more organic and soulful because the harmonic overtones are more akin to what I hear in a live music-making environment.


It's been known for decades that a conical/spherical stylus is kinder/gentler to the grooves. Thus records in less than perfect condition become more listenable traced by this type of stylus. Granted its technical inadequacies can be measured, which in turn has pre-conditioned audiophile beliefs for several generations, what matters most to me is still the enjoyment of music, and a measuring tool for that has yet to be invented.


While perusing various audio forums these past couple of years, I noticed that compared to 20 years ago there are a lot more vinyl aficionados who recognize and appreciate the musical merits of the humble round profile stylus. In hindsight, if the Retro Cool Tonearms and Cartridges article I wrote before my hair turned gray contributed to this trend, my efforts have not been in vain.