Review 2/2: Allo Boss DAC

Allo Boss DAC Review


What it is, and what it’s not:

The same section under my DigiOne review is applicable here as well. Please read that if you have not done so already.

Just as with the Allo DigiOne, the Allo Boss is also an add-on sound card for the RaspBerry Pi. It plugs into the GPIO header and utilizes the I2S (Inter-IC Sound) connections to communicate with the Pi. All the reasoning for doing this is exactly the same.

What we end up having with this Raspberry Pi and Allo Boss DAC combo is a complete networked music streaming device in one little box. It uses the Texas Instruments PCM5122 DAC chip, more commonly known as a Burr Brown DAC chip, capable of 384 kHz/32bit sound outputs. The Boss then provides stereo RCA outputs that you just have to connect to your amplifier. You need no external DAC as with the DigiOne.

This DAC implementation is done in Master Mode. This means that the DAC is not using the bad Raspberry Pi clock signals directly, but uses two of its own clock oscillators of high accuracy and quality (one for the 44.1khz and one for the 44khz multiples) to call and play the music data from the Pi at its own rate. It also cleans up the power source from the Pi, as in the case of the DigiOne, before it is used for its digital to analog conversion process.

Allo has a very nice explanation with lots of technical details and specs on their website if you want to read further about the Boss DAC.

How I got hold of it – the customer experience:

I got this little add-on DAC board with the compliments of PiShop.co.za. I did not plan on getting the Allo Boss, but Johan from the PiShop sent me this board to try out, provided I write a review of it from a user perspective and compare it to my existing gear mentioned.

So, getting it was easy. The DAC board with the familiar beautiful acrylic enclosure arrived via courier with some other parts I had ordered from PiShop. I already had all the rest of the components I needed to assemble a completely functioning Allo Boss Player.

This can be ordered as a complete kit with all the necessary bits and pieces at a slight discount from the PiShop.co.za. Currently the kit is not listed as such, you have to ask for it.

Assembly and Setup:

The same section under my DigiOne review is applicable here as well. Please read that if you have not done so already.

I took a spare Raspberry Pi 2 I had laying around, an Allo Power Supply I used for my Pi Zero, and a 16GB class 10 SD card. I then combined it with the received Boss DAC and Enclosure and stacked it together to see what the kit would look like. I then went to work and started building the complete player.

It was again the familiar satisfying Lego Technic or Meccano building experience as with the DigiOne. No surprises here. I just need to mention that putting the SD card into the Pi before you start assembling is much easier than doing so afterwards with the aid of a tweezer.

I used an Edimax EW-7612UAn USB WiFI dongle with antenna to access my network. The Pi 2 does not have WiFi, but that is not a drawback, since the Pi 3 Wifi is shockingly bad. More about this to be found in my DigiOne review under the same section.

I used PiCorePlayer as my choice of music streaming system, making use of my LMS server. I formatted and wrote the system image to the SD card and booted up the system within a couple of minutes. Configuration was very easy to set up. Just follow the online instructions for the software you have chosen.

Here are the pictures:

My listening setup:

I used the same basic setup as explained in the DigiOne review. But I introduced some further aids to help with the comparisons.

The Schiit Multibit DAC was now my benchmark or reference to gauge how the Allo Boss sounded. But now I also introduced the Schiit SYS passive preamp into the mix for instantaneous switching between the two DACs as the source to my Schiit Magni 2 Uber headphone amp, and my choice of headphones. The SYS is very basic and does nothing to the sound. It is basically a high-quality source switch with a volume control that is set to full volume all the time. Switching is a simple button press and the response is immediate. My headphone amp was the only volume control used. The volume levels of the two DAC’s were the same as far as I could tell. I verified this with a simple SPL and DB meter app for sanity.

I used the exact same interconnect cables and lengths from each DAC to the SYS, and then my usual Cardas interconnect from the SYS out to my headphone amp input. This means that the audio path for both DACs to the amp was for all means and purposes exactly the same. If anything was affecting the sound quality, both DACS would be affected in the same way.

Power sources used were the stock linear power supplies from Schiit and the Allo power supplies for the Raspberry Pi’s. Thus, all power supplies come from the exact same OEM supplier, Xing Yuan Electronics.

The Multibit DAC was receiving digital input from my PC USB port as well as from the COAX port from the Allo DigiOne Player for some variety. To change between these two inputs, you just push a button on the Multibit.

I mostly used the DigiOne Player as input for the Multibit, since I have already determined the difference were negligible in my system between USB and COAX to the same DAC. Also, with PiCorePlayer and LMS you can synchronize the Allo Boss Player and the Allo DigiOne Player to play the exact same track at the exact same time using a single LMS player control. Basically, this is how you would set it up for Multi Room Audio.

At this point I simply push the button on the SYS to switch between the DACs and the music just flows continuously, making a mere split second disconnect sound as the source changes.

Headphones used were the Sennheiser HD600, Sennheiser HD650, Audeze EL8 and the Beyerdynamic DT770 Pro 80 ohm.

OLYMPUS DIGITAL CAMERA

How does it sound:

This was by far the most fun and most time-consuming experimentation session I had in a long time!

You probably heard it before, but DAC burn-in is very real with the Allo Boss. I left it on for a week and played random tracks through it when I was not listening and comparing. The first day, I could pin point the Multibit in a blind test without a doubt. I am very familiar with that smooth, accurate and fast sound the Multibit produces. A friend and I could also distinguish between the Modi Multibit and the stock standard Modi 2 DAC within about a minute. This was verified by double blind testing. After 2 days it was still clear when the Multibit was the selected source, but it was slightly more difficult to detect. After 4 days, I had to sit a bit and got it wrong a couple of times. After a week it was super hard to distinguish the difference. There was only a very small selection of properties that remained different between the two DACs. But this was like splitting hairs. And the headphones I used were definitely capable of lifting out the details and differences.

The Boss DAC produced a slightly warmer sound, and I found the mid-range and vocals a bit more forward, true and enjoyable.

The sound of the Multibit was slightly faster and more detailed, especially the highs. But it was more neutral and analytical overall, and the warm fuzzy feeling the Burr Brown gave was not so pronounced.

While I love the detail of the Multibit, I also enjoy the Boss very much! Let me emphasize, however: it’s not day and night, its micro shades of grey. It is flavoring. Neither DAC is unpleasant in any way.

As explained in my introduction, I am proud of my Schiit DAC and believe it was a good purchase. However, I found a sound competitor in the Allo Boss, which costs about half the price and functions as a standalone, low powered, silent music streamer as well. I was hoping my DAC would humble the Boss, but it did not. It just kept up with it. They were so close that if I stepped away and came back and did not look at the source selector, I could not tell which was playing.

I made a plan then to test my sanity and called in our local Head-Fi veteran, Francois de Villiers (AKA ScubaDude on AVSA forum). I had set up everything up so that he just had to push the button to switch between DACs. He listened, compared and made blind test notes. And then we talked about it. Guess what… he chose the Boss. At this point I was happy and sad at the same time. I was happy that I was clearly not insane or have hearing problems. But I was disappointed that my DAC was being beaten by a cheaper unit. This Boss is good. It is very good. It’s not a toy or cheap junk at all. It is new value proposition for someone needing a network streamer at a price that most people can afford. This is good news for us hobbyists!

We also then switched the Multibit to the PC USB input and compared, with much more effort using Foobar2000 and trying to sync the same source file playing on the Boss and the PC. Here Francios liked the Multibit a bit more at times, but at other times heavily confused what source he was listening to. He was also very surprised about the result and the awesome sound coming from the Allo Boss Player.

Here is Francois’ own words: “On SPDIF: both nicely tidy performance but Allo seems to have better timing, bass control and more even tonal response. By comparison Modi sounded a little shouty and closed in. Not by much but noticeable. Switching to USB input on the Modi made a big difference, with the Schiit showing off what it can do. In this arrangement the Multibit came across as the more controlled, even, detailed and dynamic performer, with a confident, convincing and realistic portrayal of the music. Considering the versatility and high performance of the Allo it is highly recommended as an entry to mid-level front end for a computer based system. Would love to compare it back to back to something like a SB touch”.

Conclusion:

What do you need? This determines my recommendation.

If you need a networked music streaming endpoint for your hi-fi system, one that you can be confident will grow with you, one that sounds more expensive than it is, this is it. Get the Allo Boss Player and be done with it. Enjoy the music.

If you need a standalone unit that plays your music and movies etc, still go for something like a Raspberry Pi with the Boss DAC and change the software on the SD card to something like Kodi or Rasplex. No additional costs and the flexibility is all there in the software you choose.

If you have nothing to start with, if you have a limited budget, or you are not sure what to get, but you are desperately seeking sound quality that is comparable with the likes of a Schiit Multibit DAC, then I wholeheartedly recommend starting with the Allo Boss Player kit. If you decide later you need to change this, go for it! The Raspberry Pi, power supply and SD card are all reusable for other interesting projects. For instance, home automation (love this stuff), smart mirrors, remote IP cameras, NAS devices, print servers (Google is your friend here). You get my point. It will not be a waste of money and a hell of a lot of fun to get a Raspberry Pi and add an Allo Boss DAC board to it!

If, like me, you need some more versatility on the input side of your DAC with sources coming from your PC, your Allo DigiOne, your Chromecast or your AVR optical port, then get an external separate DAC with multiple different inputs and avoid cable swapping and software tinkering. Your different needs will then always be covered with some sort of a digital source that you most probably already have.

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