Allo Digione Signature

[steklo]

Hi,

 

I'm looking for a good  PSU solution for RPi / Digione signature as well.

 

I could imagine that a battery PSU like Ciunas ISO-PS with dual 7V outlets might be a good choice:

 

https://www.ciunas.biz/product-page/iso-ps

 

As I was told the 7V outlet is free from any regulator; that means the full current delivery is available directly from battery. As the clean input of Digione signature can take any voltage from 5V to 29V, one could that way take full advanage of that direct-out-of-battery-approach.

The second 7V outlet of the ISO-PS could be used to feed a LT3054 LDO regulator set to 5V output and then feed the dirty side of Digione (and through that at the same time RPi).

 

Nice LT3045 boards:

http://www.ldovr.com/product-p/lt3045-a.htm

https://www.mpaudio.net/product-page/sd-hpuln-ps

 

(The 5V outlet which Ciunas also offers is regulated by XRP6272 which has 2% output voltage accuracy; that is why I think LT3045 might do a better job)

 

But – the two outlets of the battery are not galvanically isolated! John Kenny (Ciunas) says this doesn't matter as any noise introduced from one outlet would get lost within the large capacity of the battery and therefore would never be apparent on the other outlet.

 

What would you think about that?

 

Best regards

Stefan

[steklo]

On 8/31/2018 at 2:58 PM, allo.com said:

Hi Stelko

 

 you need to respect the current specs of DigiOne Sig. Dirty side needs 2.5A. LT3042 from the link you provided shows a max of 1A

 

Furthermore.. the dirty side does not care much whats feed to it. I would recommend a cheaper SMPS for dirty side and a battery like you have (7V is fine) for the clean side.

Hi,

 

you're right the manual says: "It needs 2 PSUs, one for 5V/2A-3A (RPI) and a second CLEAN power that can be (5V to 6V) 100mA." But the demand for 2-3A is probably not because the dirty side of Digione takes so much, this is probably because the specs of RPi say so. Actually the power consumption of an RPi that only acts as a streamer and which is free from further tasks (musicserver, upsampling, converting file formats) is below 500 mA. Thus 1A should be enough – unless you say the dirty side of Digione signature alone needs more?

Anyway it would be really nice if the soundquality of Digione signature would be completely independent from the way RPi is fed. Have you tried different PSUs with the RPi in conjunction with Digione signature to find a cheap SMPS is enough for the dirty side because it makes no difference?

 

Best regards

Stefan

[steklo]

On 9/2/2018 at 6:06 PM, matthias said:

 

The Ciunas devices use LiFePO4 batteries. These deliver voltage output of 3.2/3.3V or multiples of these voltages. 

I am wondering how they can claim an output of 7V without any regulator.

 

Matt

Hi Matt,

 

I asked back and John said: "I use Lifepo4 batteries. These can be charged up to 3.6V & I use 3.5V regulators before the batteries that keep them @ 3.5V"

 

Stefan

[steklo]

@ Ampega:

Right, that is why I would prefer to have 7V directly out of battery for the clean side – no regulator engaged in that part at all. But for RPi / dirty side it needs a regulator to come down to 5V. Here I would prefer the 1A LT3045 regulator  instead of the 2A XRP6272 regulator (which would be implemented by Ciunas if a 5V outlet is ordered) as the latter seems to have significantly more noise wheres LT3045 is known as one of the lowest noise regulators available at the moment. I can't see how it might work with no regulator on the dirty side.

[steklo]

6 minutes ago, allo.com said:

Hi Stefan , yes dirty side requiements are only for RPI (wm 8805 takes about 50ma on top)  However power consumption is dependent on what model of RPI you have , the latest RPI3B+ (that comes with our player) needs about 2.2A on boot for short periods of time. Of course you can tweak the RPI and get much lower than that...but we advise to have a good PSU with 2.5A. Our PSU (allo website) that comes with the player is perfect for it.

No need to buy a Nirvana PSU for the dirty side?

[steklo]

21 minutes ago, allo.com said:

No need for the IFI

Isn't "Nirvana" the upcoming super SMPS made by Allo? ;-)))

[steklo]

51 minutes ago, allo.com said:

Nirvana is not ready yet.

Anyway – from what you said before I guess Nirvana would be a good choice for the clean side of Digione signature but would not at all be necessary for the dirty side. That could still be fed from your most recent 5V SMPS which comes with the player, right?

[steklo]

8 hours ago, matthias said:

 

That means they must be permanently connected to the charger which is not a good idea. 

 

Matt

Yes it's a trickle charge concept – why would that not be a good idea? In case of being afraid of any noise getting through the the battery from the charging PSU you can easily disconnect it during listening sessions. You might even use an LPSU for that purpose. Anyway I would doubt one can hear it.

[steklo]

18 hours ago, allo.com said:

yes thats correct

So that would clearly distiguish the new Digione signature from the old Digione, where a lot of people reported an obvious influence of the PSU feeding RPi despite of all the galvanic isolation of Digione and voltage filtering?

[steklo]

13 minutes ago, allo.com said:

  Of course a very good PSU will beat a 2$ part and furthermore on Digione signature we implemented a cascading network of LDOs (series) + different bypass caps (film) that make the Sig..better.

 

 

Did you evaluate the idea to implement an option for feeding 3.3V directly into Digione signature from an external battery? That would possibly take a number of more or less noisy LDO's out of the game.

[steklo]

On 9/6/2018 at 9:25 AM, allo.com said:

 Battery power in at 7.4V is  very good . Enjoy your Sig and let us know what are your hear..

 

Did you compare feeding the clean side of Digione signature from battery vs. very good linear supply such as LT3045? Some say LPSU has more dynamics and faster current response?

[steklo]

Hi RX8R3ROD and all,

 

this is a nice description on how things can go with a hifi system. Seems like we are in the same boat – I prefer my entry level AudioNote pre/power combo from the mid nineties, my entry level AN DAC (only a few years younger) and DIY speakers based upon vintage Saba Greencones from the 1950's much over most recent and more expensive systems. I heard partially refurbished Quads last year and I can understand why you like them! Actually they share some fundamental qualities with the Sabas.

 

To come back to the topic:

 

I have the Digione signature for quite some time now. Until then I had the Pi2Design 502DAC which is a very good SPDIF HAT too. But as soon as the Digione signature was on top of the RPi it was clear it would remain there. My RPi runs the minimalistic piCorePlayer software with a separate Logitech Media Server on a NAS. pCP is set up in such a way that it forces LMS to send out PCM. That means the RPi + pCP have nothing else to do than stream audiodata, no server activities, no upsampling, no conversion tasks. Wifi is switched off too. This results in a very low power consumption of the RPi which is way below the official 3A, probably around 500 mA!

 

That allowed me to use a Li-Ion battery PSU I already had with two outlets for the whole package: One outlet with unregulated 7.5V direct out of battery (able to deliver high currents for short times), perfect for the clean side, and 5V out of a LT7805 regulator which would be perfect for the dirty side. At this point the first reports here on CA came up which strongly indicated that batteries would be the way to go with Digione signature. My main concern was that my particular PSU would defeat the galvanic isolation between RPi and Digione signature when I would feed both of them in parallel from the very same battery (which I would prefer in order to not have too many devices around).

Therefore I wanted to have something else as a reference which would allow to retain the galvanic isolation. Also I was interested to find how a high quality LPSU would perform. Luckily I got the opportunity to get loaned a two railed shunt regulated PSU which years ago was strongly recommended to me by a german DIYer for an RPi/SPDIF HAT setup, the Thel "Black Pulsar". This unit is meant to supply audio gear with an average power consumption up to 500 mA. Ithas two independent rails galvanically isolated from each other.

 

Within one evening, my questions got clarified for me: It turned out that feeding RPi and Digione signature (or dirty and clean side) from the two rails of the shunt regulated PSU brought out much deeper and powerfull bass. Going on with some solo performances of piano and guitar it furthermore revealed that vividness and immediacy was better with the Black Pulsar.

Having the Black Pulsar feeding only the dirty side and battery the clean side was more or less like feeding the combo from battery completely; in any case inferior to an all Black Pulsar approach.

From that time the Black Pulsar remained and the battery went back into the closet. At no time since then there was any powering problem with the RPi by the way.

 

Later on I added a a filtering board (also from Thel) with a load of capacitors on it, which further improved the performance: Ambience became a bit larger and the imaging a bit more precise. And when we're here already, introducing a Cisco 2960 switch between network wall-outlet and RPi made another nice improvement, actually even more recognizable than the filtering board. (You can read about the Cisco 2960 switch on Naim forums)

 

At that point I can say that this is easily the best audio reproduction I ever had!

 

Meanwhile I received a nicely oversized toroid transformer from Terry (Canterbury Windings) who – as far as I know – also makes the transformers for the more expensive PSUs from Paul Hynes. Unfortunately I haven't found the time to try it until now.

 

What needs to be done is making some short and decent DC cable and get rid of the adapters. If Allo is reading: What about providing some nice DIY USB-C plugs?

 

Best regards

Stefan

 

P.S. If anyone is interested in the Black Pulsar PSU – unfortunately just when I decided to buy one, the last unit was sold. I got myself a second hand unit. I can tell you they are rare. Mr. Hartwig launched a new version of the Black Pulsar meanwhile which now is offered on his website. While the basic construction and performance seems to have remained the same, there are some things that I find better with the older one:

First: The new version includes a Talema transformer on board, the older one came without any transformer. You had to / was allowed to choose your own, incl. different output voltages for other applications.

Second: The old unit had a dial on board to limit current of each of the two rails independently (the nature of a shunt regulated supply means that all current not needed by the supplied unit gets dissipated as heat; thus current should be limited to about double the average current demand of the consumer being supplied), the new one has not. You would need to exchange a resistor to do so – or I guess you could as well ask Mr. Hartwig to do so.

Another very similar alternative to Black Pulsar is the PlacidHD PSU from Twisted Pear Audio. This is a full DIY approach though.

 

P.P.S. Just to make it clear: I am not affiliated with Thel or Mr. Hartwig and I don't get any benefit from reporting about it here.

[steklo]

On 12/8/2018 at 1:49 AM, quanghuy147 said:

Regarding the Cisco switch. Does it have fan on it? Does it make noise? Do you mean you use its POE feature of the switch to power the Raspberry?

 

In case of the Signature , it has its own clean power source. Can using clean power for Pi can improve the sound further?

Sorry for being answering so late...

 

The Cisco 2960 doesn't have a fan, at least those units with low numbers of network ports. I have one with 8 ports and it definitively has no fan. It doesn't have a POE feature at all – I think there is a related unit which has – so no, I don't use it (and actually cannot use it and even would not want to use it) to power the Pi. I have a separate LPSU with two rails to power clean and dirty side of Digione signature.

[steklo]

For those in Europe I'd once again throw in the Thel Black Pulsar shunt regulated PSU. I described that before here and I'm still very impressed:

 

https://audiophilestyle.com/forums/topic/49667-allo-digione-signature/page/17/?tab=comments#comment-903620

 

It is semi DIY: The board is ready for use you need to put it into a case and connect cables to it. If I can do it, anyone can.

One advantage of the Black Pulsar is it's got two separate rails, so you have a high quality power source for both clean and dirty side of Digione signature galvanically isolated from one PSU.

 

For those in the U.S. Twisted Pear Placid HD would probably be quite similar, though with the necessity of a full DIY approach.

 

[steklo]

Hi,

 

can I use both SPDIF outputs (BNC & RCA) in parallel at the same time and feed two different DACs?

 

Best regards

Stefan