Allo DigiOne

Product Information

Since this is a digital stream the most important aspect for "absolut best" is jitter. Jitter in digital domain directly translates into analog errors. Second, is noise. Lowering the noise that’s injected in your DAC will produce some (small-to-none) improvements.

If you’re DAC possesses a SPDIF digital input, RCA or BNC one, and you would like to experiment with digital signal cleaning but you find USB regenerators and the use of two USB cables expensive and/or cumbersome – then Allo DigiOne could be an affordable alternative that being a HAT and not the external device requires only one digital cable. But don’t get filled by its affordable price (compared to most similar devices), this little HAT offers a very noticeable sound improvement over Pi’s USB outs (and the result would be the same if you compare it to USB outs of most PCs).if I’m honest, I think I would have needed an A/B test to tell the two Dragonflies apart - at least when listening through the speakers. The idea behind the quirky looking Allo DigiOne Signature streamer is this; take a Raspberry Pi mini computer which can be had for tens of dollars, pimp it, and challenge conventional streamers?

The only thing left to turn your Raspberry Pi into a full flagged audiophile streamer is using all this with a low noise power supply, but that’s a topic we’ll cover another time. I hit upon using it as a Roon end point streamer as Pi’s can be used as such. As long as your Roon server is on the network the Roon app recognises it as ‘Volumio’ under Settings>Audio. The techie bit maybe? The DIYINHK works well but it is too expensive. You can buy a DAC for this price with just as good of a USB input. If this was a few years ago, sure, there would be a need for this when USB input was less common. Still, this may be a cheaper option for some to get better USB such as on Schiit DACs that don't have their "Gen 5" USB input. For a much cheaper option, you could look at Topping D10 which is a DAC but also has S/PDIF output. But little precision. In digital world, SNR have no place (almost…). SNR is for analog part. Yes, you must have a good power supply, the only thing is to not have signal perturbation to high. I ever see lot of digital circuit running well with -6db of noise. In digital world this is binary : 1 or 0. Of course, since this is based on RPI compute, we decided to include the standard RPI connector. Anything that works on an RPI will work on the USBridge Sig. For example, you can use a DigiOne / DigiOne Sig to make a full fledge streamer that outputs USB, BNC and coaxial.

We see identical performance from both, substantially lowering the jitter and noise products from Schiit Modi 2 Uber. What is left from prior testing, is due to deficiencies in the rest of the Modi 2 Uber DAC than anything to do with digital input jitter. I would like to explain a few things on the RCA output. The standard on coaxial is 75Ohm , unfortunatly RCA connectors and RCA cables are not capable of 75Ohm because of geometry/physics . We spoke to a few manufacturers of DACs and some of them already implemented 50Ohm impedance (since 75R is not possible) . Basically instead if doing text book , blind implementation , we take in consideration real world impendances and with a good DAC manufacturer 50R will be implemented on the RCA coaxial input I also used the DigiOne Signature into various HiFi system configurations (see system below). You could tell the noise floor is a bit higher than the dCS Bartók and bass not as accurate and tight but surprisingly, closer than you would think with diametrically competing HiFi. The same was true of the other system. Volumio supports Qobuz and Tidal but you have to pay extra for it. There are also various free Spotify Connect plugins for Volumio.

A more essential A/B is how the Allo DigiOne-loaded Raspberry Pi compares to its Just Boom equivalent. Let’s not beat about the bush: the DigiOne is markedly better. It sounds smoother, richer, more easeful and offers a slightly taller and deeper soundstage than its less costly UK rival. So if you want a leftfield idea, in a quirky looking product, and to get maximum performance instead of conventional streamers, it’s definitely Allo Allo with the DigiOne Signature. Just make sure you use the correct power supply combination. Very recommended and it achieves the 13th Note for the money! Manufacturer Clean the Power supply coming from the raspberry PI through hi performances DC regulators and filtering capacitors. As always, the cleaner the power is, better the musical outcomes (Signal to noise ratio). The DigiOne Signature requires two power supplies: one for RPi and one for the Digione Signature. I powered the RPI with the supplied switching supply from Allo and used my sbooster linear power supply for the "clean" power. Both inputs are UBC-C connectors.In our quest for digital perfection, we asked how we can improve the design and give you the ultimate DigiOne. Although I’ve not had my DAC for long, it wouldn’t be any surprise to see me make another change. Having a Rega Brio amp, I’d like to give a Rega DAC ago, but of course they’re no longer in production. Just from a visual inspection you will immediately notice that this board is literally filled with components. I was just wondering why all this stuff for S/PDIF… I have been playing with the DigiOne with almost a month now, and I’ve been able to listen to it with a variety of DACs I do know well.

Now, what I don’t like about this. I would have preferred to have a way to feed the DigiOne and the Pi separately. Allo claims there is no need (and they are probably right, considering the DC regulators and galvanic isolation) but I think this is anyway a Nice to have feature. What you see on BNC is the right implementation as per the standards. 75Ohm all the way since cables and connectors are designed that way. Our transports have different outputs. USBridge is feeding your DAC through USB and DigiOne is using coaxial/bnc. Depending on your DAC inputs you need to make a choice. To lower the noise of the USB, we had to lower noise on EACH rail. In total, USBridge Sig uses more than 30 LDOs. Even the SD card power rail has a dedicated LDO. There are zero switching elements on board.

Fast forward again - the BOSS DAC was sold and in its place a Schiit Modi 3 DAC (see John Darko’s video for the reason why). About 3/4 months later, I had the opportunity to trade up to a 2nd hand Schiit Modius which I did. this DAC is with me still (at the moment anyway - and until GAS takes over again). Galvanic isolation would have been the best solution for coupling the card with DAC (floating circuit, non interference distribution), but the choice is to use digital isolation. Normal, it miss some space and will give some jitters problem. In this choice, your are electrical coupled with the DAC. So, if you don’t want to send some noise to your DAC, you must take a particular attention to have a clean signal to send without pollute the other part. It is why the power stage is so developed on all part of the card. HATS. Not The Blue Nile’s sophomore LP but that given by Raspberry Pi to add on-boards for their small-board computer (SBC). A HAT (Hardware Attached on Top) slides on to the 40-pin connector to extend the Raspberry Pi’s functionality; during the boot process, the HAT is auto-registered and auto-configured by the host operating system. No delays, no user intervention and, best of all for the DIY-allergic, no soldering. If I get bored, I will grab an Allo Boss and see how it compare. I have Piano 2.1 without Kali - use in Allo DigiOne Signature and DIYINHK PRO3Z both provide very clean S/PDIF outputs. While the Allo outperforms it a bit at micro-level, there is really no fault here to worry about. Between the two though, the Allo is much more capable from functionality point of view since it has built-in networking (with the addition of required RPi board). That, and excellent performance gets Allo DigiOne Signature on my recommended list.