This is a slightly different review for me. It is hardware review that focuses on a lot of software not supplied by the hardware vendor. It is also about integrating both hardware and disparate software systems. Finally, the end results totally surprised and delighted me and everyone else who has participated.

The Allo USBridge Sig arrived with the Volumio software installed. Since I reviewed the Volumio Primo over the summer, I thought that starting using the Volumio on the Allo was a great idea.

As a refresher, Volumio software is a complete music playback system for local files, streaming services, and Internet Radio. Volumio is a complete Linux OS with a competent and flexible music player that is lightweight and designed to run on small computers. MyVolumio is an add on SAAS component to bring more services to play.

The Hardware

By using the Raspberry Pi 3+ compute module instead of the standard Pi 3+, Allo gains the flexibility to provide dedicated external interfaces. The USBridge Sig board is engineered to isolate the ethernet noise from the compute module and to isolate the clean USB port for your DAC. By providing the standard 40 pin interface connector, they give access to HAAT systems such as the DIGIONE Signature SPDIF board installed in the case I have.

There are two separate power supply inputs on the case, one for the mainboard with the Pi computer and one for the DIGIONE board set. The Shanti power supply manages this with its two outputs. The Shanti is a linear power supply with super-capacitor outputs. It ships with multiple adaptors for different input connections, providing two fixed outputs 5V 3A and 5V 1A as a match to the Pi boards and HAATs.

Allo has “earth” or ground binding posts on both the Shanti and its case for the USBridge Sig. Allo is very insistent that you run a separate grounding connection between the devices and include your DAC if there is a way to do that.

That wraps up the hardware and a once over lightly for the Volumio Software. Now to the testing and how does it sound?

First, let's set the “sound-stage!”

The Software

I am working through four Operating Systems that provide different services on the Allo USBridge Sig in this review.

Ropieee is a Roon endpoint application, and it has an XL version that does more. DietPi is a general-purpose Linux implementation for the Pi. Volumio is a music playback system that is a stand-alone and multi-room music playback system that also an SAAS component. MoOde audio player is a stand-alone “Audiophile-quality” music player.

I flashed microSD cards for this testing. They are The V30 speed cards, and they help performance on Volumio and MoOde Music Players. I want to try the faster UHS II V60 or V90 cards to see if they improves performance.

Here are a couple of notes of caution going down the software path that this hardware leads us.

Qobuz in the open-source world Qobuz was suffering theft of services against their service. They have made several changes that, in effect, shut out some Open Source systems access. Today for my testing, I cannot merely use DietPi to play Qobuz streams.

Problems in the Linux 4.19xx kernel As of this writing, the current version of the Linux kernel used by some of the player software has a defect that causes clicks/pops to some DSD DACs. (Including mine)



This testing involved lots of learning and unlearning. There is fussing / fiddling around with software and settings and a whole lot more. I have shut down, rebooted, yanked the power, swapped USB cables, and typed on the Linux command line for a lot more hours than ever before! As an example: after Volumio I moved over to MoOde to get a feel of how it worked. I did a terrible job of reading, let alone understanding MoOde. The underlying music player software is MPD, and you have to configure MPD with your USB DAC attached. Read the Manual! Get on their forum for help.

I did some of my initial listenings on my Schiit LYR3 with multi-bit DAC and with my Chord Mojo. The results were rather promising, and it helped with the break-in. Then I moved into my main system and spent a few days listening, bouncing between my Server and the Allo. The Allo started on a good foot and over time, it really hit its stride. After about three weeks of on-time things were very stable!

The Hook-up

I have the USBridge Sig connected directly to my Ethernet network, and my Xeon based server/streamer connects via an opticalModule Fiber Media Converter to the same network. I swap the Lush2 USB cable from the Xeon box (+tXUSBultra) to the USBridge Sig.

My Xeon box runs Euphony OS so it can swap around between the Roon components and Stylus player. I have primarily been running it with Roon + StylusEP.

I have an i7 NUC in my office that I also have Euphony OS on. It runs as a second Roon server. Again it as the same flexibility. It is connected to the Ethernet network directly.

My music library is on a QNAP NAS located in the basement. There is no extraordinary power or network, just Ethernet, to the main Ubiquiti Switch.

My system setup before the testing is shown in my profile here on AS:

@bobfa Audio System

Beginning to Listen: FINALLY!

First we have to have music!

I want to thank @The Computer Audiophile and @austinpop and Kii Audio for their Qobuz Playlists. They are very helpful in finding a variety of music and not get stuck on “that one track.” I have also added a playlist of some of the tracks I use. I have more but this gives you a flavor.

There are dozens of permutations, hundreds of settings and options that I could have tried. I have kept this “simple” I am using three configurations. On Device Music Player, Squeezelite, and UPnP. Where Possible!

I started my actual listening tests using Ropieee as the Roon Bridge. I was disappointed in the sound quality. Many of us have found that Room Bridge has some limitations. We have moved to Squeezelite. My time with Ropieee ended rather quickly.

I setup DietPi next, and to be honest, I did not bother listening to it much at all. I did not want to learn how it worked to run different software packages, too much GEEK!. Maybe it was just a bad day. I want to listen to music, not manage another computer. If there is time later, I will setup DietPi and compare it to the others. Yes, I have to read the manual! I am sure I am not giving DietPi a fair shake yet.

That left me with two options to work with: Volumio and MoOde!

As noted above, I started with Volumio and MoOde as a stand-alone streaming solution against Roon+StylusEP on my Server. I could not conduct some of my tests fairly as Volumio can do Qobuz via SAAS, and MoOde only plays local files without a different control point application.

Volumio works fine on the USBridge Sig, I had some problems with the iOS App finding the Allo on the network. In the end, Volumio did not sound as good as MoOde. It lacked clarity and depth in comparison. I have now narrowed myself down to one OS, WHEW!

The MoOde player's user interface is pretty simple and clean. Using the UI on small screens is hard. On a large iPad or a laptop it is fine. My system also has a large display hooked up to the Allo. I use a cordless mouse to navigate. MoOde has surprised everyone who has listened to it on my system. It is great! In any mode we tried.

I am still trying to find a good UPnP control point for iOS devices. I guess good is relative. I finally got MConnect HD working on the iPad after finding a bug that took me two days to work out. USE the GEAR icon to find your renderer. I also used BubbleUPNP on my Android Phone. Of course, that is not all you have to do. You need your local music on a device that is UPnP. Fortunately, all I had to do is to configure Plex on my NAS to include my music folder.

During listening, I did not bother to search in Mconnect ; I just ran down the file/folder structure. For some reason, there is no artwork displayed. I was mostly getting the PLEX logo on my local library.

This testing showed much more of the promise coming from the Allo, but, I had to pause this project for about 10 days.

At this point, I was dizzy trying to keep notes flipping back and forth, WHEW. I had my friend Rich come over for coffee and music. Comparing the Allo and my Xeon server has been a self-defeating process. I have been so happy at my progress in building something that sounds so great. Only to be squarely kicked in the rear by the Allo USBridge Sig!

In summary, I think that my friend Rich said it best; he would be happy with either device! After another few days of listening, I have to agree. BUT WAIT THERE IS MORE!

I switched MoOde over to Squeezelite and started using it as a Roon endpoint. So now, the software paths are similar. We are “closer” using Squeezelite on the Allo and StylusEP on the Xeon. The made the A/B a bit simpler as long as they did not crash the USB bus!

We have a photo finish. The imaging is almost identical. I had some help with blind A/B testing, and it is to the point I have a tough time telling the difference. There seems to be a bit more detail in the USBridge Sig and a little more harmonic fullness in the Xeon box.

This past weekend my friend Eli came over and listened. He made many of the same conclusions that others have made. The USBridge Sig is a great piece of hardware with the right software to make it shine. (There will be more notes in my upcoming update on the DIGIONE Signature boards)

The last lap

Can I make the USBridge Sound Better?

(Note that during this testing I was using MoODe with Squeezelite)

While I was at this, I created a side project to try to “improve the sound quality” from the Allo!

I did an A/B with and without the txUSBultra connected between the Allo and the Kii Control.

While this did make a difference, it was not enough to even consider back ending a $1500 device on the Allo. The USB side of the USBridge Sig does its job, Thank You Very Much!

The next A/B trial was to move my Sonore opticalModule to the Ethernet input on the USBridge. I did not spend much time listening as I had to reboot on every change for some reason. I did not hear any difference with the FMC inline.

Note that the opticalModule makes a very noticeable difference when connected to the standard Ethernet port on my Xeon server. Again the folks at Allo seem to have done a great job on the input side.

In Summary: The Hook-up

Note that I fronted the Shanti power supply with a Transparent Generation 5 High-Performance Power cord. Yes, the cord costs more than the Shanti!

The USB cable I am using on the output of the USBridge Sig is the Phasure Lush’2 cable as the last link to the Kii Control. But again, this cable is around $250, which is more than the USBridge Sig board costs!

I feel that it is a very fair testing method, keeping everything the “same” around the unit under test.

In summary, the Allo USBridge Sig is an excellent value for the money, and it plays well above its price class. Buy it in the bundle with the Shanti power supply and get the metal case; it is worth the price!

The hardest part of this review was starting to learn how all the different software packages work and finding software to do thinks like UPnP. It is my understanding that Allo is working on improving the software situation!

Software and hardware stability in these rather complex systems can be a problem. Once running, the systems were stable during most of the testing.

To be completely open: more than once, I confused the USB interface on the Kii Control by swapping between devices, and that caused me to have to power it down. I am having software issues with Roon on Euphony OS (RAM Loaded), as the system would stop talking to the DAC over USB that I am still debugging. The problem seems to be around the audio endpoint in Roon. I am seeing this on both of my Roon boxes and with other DACs.

Going forward, I am set up to test the DIGIONE Signature board set on the USBridge Sig card. Expect additional reporting on that soon.

In closing, I almost hate to admit that the USBridge Sig with the Shanti power supply sounds better than my custom-built Xeon.

Just One More Thing!

As I was finishing up my review I had to go back over my listening and my configurations, ONE MORE TIME. I started back using the Allo as the render in with Roon on the NUC server and Squeezelite on the Allo.

Then I went back to native MoOde and UPnP for Tidal and Qobuz. The soundstage opened up, there is more detail. Vocalists are more defined. Listening at lower volume levels is even more satisfying.

Maybe there is something to what I have heard about MPD sounding the best? The MPD/UPnP path eliminates a lot of software, network traffic.

I am now using the USBridge Sig as the main / only device in the music system and I am storing the local music on my NAS with an SMB share with the moOde Player. Adding in streaming from Qobuz and Tidal using Mconnect HD rounds out the mix. So one app on the iPad for streaming and Safari Web browser for local music playback. This is not Roon but it works and sounds great! I will run with this for a while and see how we all feel operating the system. I know that I will be happy to just listen for a while and not be testing.

Bob Fairbairn

OK, OK; I still have to do the DIGIONE Signature ! I promise.

Product Information

USBridge Sig Board is $239 (link)

DIGIONE Signature boards $239 (link)

Shanti Power Supply $159 (link)

Case for Board only is $20 (link)

Case for Board with space for DIGIONE $23

**Look into Allo combination pricing!

Other equipment in the mix

Kii Three + BXT + Kii Control

Xeon server with HDPlex400

Custom NUC with HDPlex200

Modified SOtm txUSBultra

Sonore opticalModule

Lush2 USB

Ghent JSSG360 USB

Transparent HP USB

Transparent HP Ethernet

Ghent JSSG360 Ethernet

UpTone Audio LPS-1.2 running the txUSBultra

Transparent Audio HP power cables and power bank 6

QNAP NAS

Ubiquity UniFi Network

Primary Software used

Bubble UPnP on Android

MconnectHD on iPad for UPnP

MConnect on the iPhone for UPnP

MoOde OS

Volumio OS

Roon

Euphony OS

Squeezelite Roon Endpoint

StylusEP Roon Endpoint

Plex server on QNAP NAS

______________

The purpose of life is not to be happy.

It is to be useful, to be honorable,

to be compassionate,

to have it make some difference

that you have lived and lived well.

Ralph Waldo Emerson

“Enjoy the music and the fun.”