Low-cost, high-performance Ethernet audio
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Reviewer: Richard Varey - TNT New Zealand
Published: June, 2018
Having looked at a range of hardware options that are viable alternatives to expensive big boxes, I now look at some software for playing music files with those units, and find that it isn't necessary to spend money on proprietary players, as a huge worldwide community is beavering away continuously improving open source operating systems and audiophile music player software. I then complete my survey by looking at a few related accessories that enhance the listening experience.
One attraction of SBC-based media players and streamers is that they run with a free operating system optimized for the RaspberryPi hardware, and there are several readily available options.
As far as I can see, there are six simple options for running a RaspberryPi and DAC as a standalone music player/streamer: Max2Play, MoOde, Pi MusicBox, Rune Audio, DietPi, and Volumio (developed from RaspyFi). The latter is very easy to use and seems to be the most popular.
The Collybia team favours MoOde, so I first used it with the Collybia Mamboberry. During my auditioning period, an update to MoOde v3.7 was not free of charge, placing it at odds with all the other open source software options. However, already v4.0 is available, notable for the option of booting from a USB stick or microSD card. And it's free of charge again. This is significant, as all the other popular operating system/player software is free.
DietPi is offered by Allo, who seem to be involved in its development. Whilst very functional, it as yet doesn't have an easy to use graphical interface, so some familiarity with programming commands is needed. Both Volumio and MoOde have a very sleek GUI, which includes online updating.
As a long-time user of JRiver Media Center on my PC, I became aware of their software for RaspberryPi 3 Model B. JRiver IdPi on microSD is Media Center for RPi. Jim Hillegass kindly sent a sample of the Id software, including JRiver Media Center 22, Raspbian Linux, and Engen, ready to use on a 16 GB microSD card (US$ 40) (there's also a 128 GB option for US$ 90, providing local file storage). JRiver also offer Id players https://jriver.com/Id/. IdPi worked flawlessly, and was an interesting experience for me seeing MC running on the RPi when I have previously used it exclusively on my MS Windows PC.
My initial ranking after researching prominent software options, and based on comments in various online forums, and my own experience of ease of use, is: Volumio, IdPi, MoOde v4, then DietPi. Functionality is very similar, as is sound quality of files played, so it comes down to ease of use and aesthetic preference. I note that Max2Play is recommended for the JustBoom unit, and that it has an equaliser, and as I haven't tried it I have no opinion on its suitability.
I can't hear a difference in sound quality among the software/player options, and I enjoy using all of them.
During my discussions with vendors, and TNT-Audio readers, it became apparent that a range of power supply upgrades and signal conditioners are available to further enhance the listening experience.
I get asked often if a linear power supply will upgrade sound quality.
Linear regulated 5VDC power supplies regulate the output using a dissipative regulating circuit. They are extremely stable, have very low ripple, and have no switching frequencies to produce electromagnetic interference (EMI). Galvanic isolation, if included, provides input-to-output and output-to-ground isolation.
The JustBoom folks sent an Official RPi Power Supply (typically about $ 20) as part of their kit, and this seems to be the key to reliable high quality sound from such units. It seems that current capacity to run both the SBC PC and the DAC HAT is key, and 5 V at 2.4 A or higher is necessary. Some units are being supplied with underpowered power supplies that can introduce instability.
The Collybia unit stands out as it uses a proprietary 5 V - 3 A linear power supply delivering stable current with ultra-low noise. Collybia recently introduced their Mambo power supply (€ 140) and kindly supplied one for audition. I've been using it with the various RPi/DAC units, and have been pleased with the sense of stability and capacity to easily run the players/streamers.
An Sbooster BOTW P&P ECO 9 V - 10 V upgrade power supply (€ 270) is recommended for the TauDAC (www.sbooster.com). The Sbooster rationale is, quoting their website, «the quality of picture and sound is influenced by the power supply: if the power is not sufficient, a device can not really perform well, that is what you see and hear. Lack of power manifests itself in turmoil, a flat stereo image and a “harsh” sound. Unfortunately, not all manufacturers provide their devices with a good power supply». The Sbooster audiophile power supply unit combines their own technique for energy saving, more power, and efficiency with the best elements of a precision linear power supply. They call it the “best of two worlds” to ensure that an audio device will perform at its best.
Also during this survey project, iFi Audio introduced their iPower compact 13 W super-low noise switchmode power supply ($ 99), which they claim performs better for audiophile application than a linear power supply. A range of output voltage and current ratings, including specifically for 5 V - 2.5 A for RPi, 9 V - 1.4 A, 12 V - 1.1 A, and 15 V (presumably 850 mA). I have used one on my iFi iTube unit, and the sound quality improvement was immediately apparent when introduced to my system. This makes the variety of linear power supplies, mostly from China, on offer on eBay etc. seem expensive, and risky in terms of quality and reliability.
A notable DIY option is the Walt Jung super regulator (some designers and builders use the term regulator to describe the feature of stabilising the current output). The design rationale and construction details are widely discussed on the web.
I also explored a couple of further options for digital conditioning that are claimed to remove noise and thus enhance the musicality of playback.
Ideon 3R: www.ideonaudio.com
The Ideon 3R USB Renaissance (€ 200) sample was supplied by Collybia. The name refers to the three functions of the unit. It redrives the signal to improve transmission from the incoming USB connection, it reclocks the signal to with low jitter, and regenerates the data stream with a low-noise power supply.
The good folks at Collybia have become agents for this product, and I figured that if they were impressed by its performance, then I should try it out in my system. I was told that listeners at a recent hi-fi show demonstration were left with their jaws dropped when they heard digital files played with this device in the line to the DAC. One comment was «what have we been listening to before this product was added?». Time for a listen, I thought.
The device is very small, measuring just 75 x 55 x 17 mm, and weighing a mere 70 grammes. It employs a high-speed controller chip to re-clock the digital signal with ultra-low jitter oscillators and to minimise signal transmission losses. It also provides a clean 5 V bus to a DAC via its additional ultra-low noise regulator. All that is needed to get running is a nearby power outlet and a second USB type A-type B cable.
In the minutes after I installed the 3R USB and hit the play button, the first things I noticed were obviously enhanced clarity and presence, then that transients/dynamics are fast and clean. After extended listening I've concluded that with the 3R between PC and DAC, the soundstage is bigger and more open - instruments are more clearly separated and tone is more natural, and bass is more forcefully rendered.
I have a minor quibble with the design execution. Why is the green power LED so much brighter than the orange USB connection LED which isn't bright enough? At first glance the latter looks faulty - it's light output is really quite anaemic. Otherwise build quality is very good and the metallic part of the case is reassuringly substantial in feel.
This is one of a number of USB conditioners I've auditioned, and not the most costly, yet I am convinced that it is the most strikingly effective. My jaw didn't drop to the floor, but my 'pleasure grin' never left my face whilst the music was playing. Now that's what I call a most worthwhile tweak. Top marks to the designers, and a big thank you to the Collybia guys for creating this listening opportunity for me - much appreciated.
Etalon Isolator: www.etalonacoustics.com
The Etalon Acoustics Ethernet Isolator (€ 390) sits in the Ethernet line between file source and player - it's a noise filter eliminating electromagnetic interference. Its case is the same as their StrEamer and musicStream digital media servers. The value-for-money is in the utility of these units. They have invested in sound quality/musicality performance and production quality, without padding the price with additional cosmetic appeal.
I now run CAT6e cable on my home network, and have had the Etalon Isolator in the circuit from PC to media player for some time. I don't have a way to measure noise in the network cabling, so my assessment is subjective, as indeed it really ought to be. I'm not aware that I had a discernible noise pollution problem, but I can say that the sound quality from the current setup with the Etalon Isolator in circuit well exceeds that of my carefully tuned SACD player, so I won't be removing it anytime soon.
After months of discussion, deliberation, and experimentation, as well as many many hours listening to my music, I am staying with what I am calling (data over) Ethernet audio. My reasoning addresses all of the user concerns - the sound quality with all of these device configurations is excellent, in some cases simply superb; set up is easy (on most); control is easy; expansion is easy. Mostly, the units can be purchased pre-configured for plug-n-play. Control is on my smart phone and tablet with free or low-cost apps. Costs are, compared with 'mega silver box' servers/streamers and DACs, very attractive.
Music playback naturalism, resolution, definition, and dynamics with several of these units surpasses that from my Pioneer PD6 SACD player, even with it's Air Studios tuned Legato Link and Pure Audio features. And I'm reluctant to go back to audio through USB.
After six months of auditioning all of these products, I have settled on my picks. All units are worthy contenders in my quest for high-performance at low-cost. All deliver superb sound quality. These are especially refined.
And the winner is... each of these products. They are all highly functional and excellent value for money. Your choice will be determined in part by the type of output connections needed to integrate into your system, your hard drive configuration, preferred styling, and whether you wish to and can avoid using a PC, and the availability of a wired home network, as well as your budget.
Overall, the TauDAC is my favourite for richest audiophile listening experience, followed closely by the Pi 2 Design 502DAC, the Etalon strEamer and especially the musicServer, the Allo BOSS, and the Allo USBridge. JustBoom take my praise for most stylish presentation. Value-for-money is most impressive from Collybia Dan Allo. My favourite accessories are the Ideon 3R conditioner and the Collybia Mambo power supply.
Which ever way you go, you'll be impressed and pleased with the sound quality, the ease of use, and the substantial savings from not buying a big shiny server/streamer or dedicated PC and DAC. For example, my $ 1,100 combo is easily outperformed by a $ 135 bundle of RPi3/DAC+ Pro/SD card/case/power supply.
An entry-level high-performance player/streamer for $ 160, a high-end audiophile player for $ 675, an audiophile DAC HAT for $ 65 to $ 129, or an audiophile transport for $ 180 is already an easy and readily accessible reality. You just need to know where to look and what to ask for. And when you're enjoying music through your low-cost high-performance audio source, there are many other projects you can apply the RaspberryPi to around the home and office.
As the convenience of 'online' music access becomes commonplace, and the disc carriers are discarded, I am even more convinced that superior rendition of high quality music files is easy and affordable. Whether the files are streamed or downloaded, it is now possible to exceed the sound quality of CDs with high-resolution files without a mega DAC and server budget.
It's important to tell the whole story if my review is to be of good help to prospective users. I noted a few niggles whilst using these products.
Tricky software setup with non-intuitive interface - DietPi.
The small cases are tricky and a tight fit. The HiFiBerry metal case, for example, has cutouts that don't correctly align with the sockets. The original Mamboberry case isn't quite deep enough to accommodate the additional wiring for the switch and display without pinching, and the snap together JustBoom case is tricky to get open.
The JustBoom unit's lightness is a bit of a negative, in that it tends to get moved around by attached cables.
Low-cost power supply units are overly bulky, with wrong pins supplied for New Zealand - Allo.
Copyright © 2018 Richard Varey - richard@tnt-audio.com - www.tnt-audio.com
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