Allo DigiOne board

Because of the way i2s and spidif are implemented. One has embedded clock and i2s has separate line.

I thought the same as 75-ohm is the SPDIF standard and I would guess 99% of people using the Digital Coax output of the DigiOne are using a 75-ohm RCA cable (marketed at 75-ohms at least - how close to 75-ohm, due to RCA geometry limitations, who knows, as you said also).

Johan has been gracious to send me a replacement DigiOne for a faulty unit - amazing customer service.

Now Iā€™m getting a Blue Jeans Cable BNC-to-RCA cable made - not expensive and at least I reduce one RCA connection/interface in the chain.

I doubt it will make an audible difference but at least I can put the DigiOneā€™s 50-ohm RCA output out of my mind and reduce one RCA connection in the chain.

Would be interested to see your measurements nowā€¦

Hi Johan

I received a replacement DigiOne yesterday.
Thank you very much for your prompt replacement.
But I am busy with other things and have not yet tested the new DigiOne.
I will try to test it tomorrow.

Hi Stephane,

Iā€™m sorry.
I will try to measure tomorrow.

Have fun and keep us updated.

No need to be sorry! I am just curious to see additional measurements, and of course read your impressions.

Hi Johan,
It turns out I have Raspberry Pi version B, which is 26pin GPIO. I know that I still could use the kali / digione with some modifications, am I correct?

After receiving my replacement board super quickly and after being surprised to read about the DigiOneā€™s digital coax connector using a supposed SPDIF standard 50-ohm, I replaced my BJC digital coax RCA-RCA cable with their BNC-RCA, same Belden 1800F cable.

So only the other end of my cable is now a pseudo true 75-ohm, instead of both ends (so one less RCA interface). Although iFi say their SPDIF Purifier end is 75-ohms or close to it.

And Iā€™m now super pleased with this sound and definitely say this now beats my Digi+ Pro in my system.

After a couple weeks of proper system and brain burn in, Iā€™ll see if the DigiOne allows me to lose the iFi SPDIF Purifier at the Dac input.

Kudos to Allo.

Thx you very much Sean .

:blush:

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Little update:

Iā€™ve made the digi one my default input now.

I had planned to use the newly released RoonAIR streaming for solo/evening listening, on the basis that it would have be ā€˜betterā€™. But I have to say after a couple of weeks Iā€™m still barely (if at all) able to discern a difference between that and the Allo.

So, since having the two inputs causes much confusion for anyone else that uses the system (ā€œuse Devialet on Ethernet for just the lounge, but if grouping use Allo on AES inputā€ was met with gazes of ā€˜oh for goodness sakeā€™) , i leave it as the permanent input, which is grouped to the kitchen most of the time. I donā€™t generally even bother ungrouping - setting the Allo to sync master seems to deliver on its promise and the Devialet always sounds just as good when grouped.

I would like to lose the boxes, so if the Devialet new streamer is RAAT I will definitely go that way, but meanwhile Iā€™m very happy. :slight_smile:

No problem Johan, thx for the first class support and first class product.

Now that I am very comfortable replacing the HiFiBerry Digi+ Pro in my system, I am looking to remove the downstream iFi SPDIF Purifier - in particular for itā€™s galvanic isolation.

Of course I will let my ears make the final decision but can you share more info on the digital isolation of the DigiOne?

I understand the power and data lines are isolated - this includes the ground plane?

Many thanks again, Sean

The Hifiberry Digi+ has now gone from my system too in favour of the DigiOne. I will try the USBridge too before deciding which to use in the main system.

As an aside I am Building another complete system for my daughter using a RPi3 with Kali and Piano 2.1 in dual mono mode. I have to say is sounds pretty good!

There are 2 ways to isolate the spidif signal

  1. Use a transformer in the end. Unfortunately transformer distorts signals.
  2. Use digital isolator + isolated DC (ground is isolated)

We chose the latter.

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Thanks, since power, ground and data are all isolated and then reclocked, I should be able to remove the iFi SPDIF Purifier from the chain.

Iā€™ll let me ears and brain adjust to this new fantastic sound first, then remove the iFi after a couple of weeks to test.

Hi, all. Will the BNC be better than RCA?

Only from my limited experience, I would use a Blue Jeans Cableā€™s BNC-RCA cable if your DAC only has digital RCA input. Thereā€™s a high chance your DACā€™s digital RCA input is optimised for 75-ohm (optimised, not true 75 ohm, as discussed earlier up in the thread).

The DigiOneā€™s digital RCA output is optimised for 50-ohm.

Iā€™m definitely not an expert though. Just personal experience with my system.

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Theoretically yes. BNC is a true 75Ohm impedance and physical connection is slightly better .

Practically , depends on your particular system and how RCA/BNC is implemented at the DAC side.

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Thank you Sean! Itā€™s really useful!
Now I know why thereā€™s a bnc output on Digione and hifiberry digi+ pro support it.
So, even use a BNC-RCA cable would be better than RCA-RCA, right?

In my system, yes thatā€™s the direction I went and am very happy.

It can vary between each system of course.