Allo isolator - Roon recognizes the bridge but DAC is silent

I have a raspberry pi configured as a roon bridge. Recently i added an Allo isolater between the pi and the hifi berry.Roon recognizes the bridge but when
I start a music track nothing comes out. What goes wrong
Regards Jur

Hi @jur_osinga ---- Thank you for the PM. We usually handle any support related question out on the “Support” thread of the community site so other users have access to any information being shared, should it be helpful if they are experiencing a similar situation.

Would you mind if I made this PM a public topic and we can continue troubleshooting from there?


No problem
Regards Jur

Thanks for getting back to me @jur_osinga, very appreciated!

Moving forward, to help me better understand this behavior you are experiencing with the Allo Isolator, may I very kindly ask you to please provide the following:

  • A breif but accurate description of your current setup, using this link as a guide.

  • Before you installed the Allo isolator, where you experiencing any issue playing back to this endpoint?

  • Please confirm that the isolator is configured based on all the recommended specs as seen here on Allo’s website.


Current set up:
Raspberry p2,Allo Isolator and HifiBerry dgi+pro.
The isolator and Hifi berry hav a separate power supply.
Before i installed isolator i used the raspberry with the digi pro, which was working perfectly.
when the isolator was installed Roon recognized the whole set as a bridge,tracks where found on my nas but when playing them they did not start and skipped after a few seconds to the next track and so on

As far as I’m aware, Kali and Digi+ Pro will not work together – Kali is expecting a slave DAC, while the latter is a master device.

Nevermind – not about Kali. Cleaned my glasses. Reading skills restored now.

Hi @jur_osinga ----- Thank you for touching base with me and providing the requested feedback, but more importantly, thank you for your patience. My apologies for the slow response.

Moving forward, can you verify for me if you are able to successfully use the mentioned endpoint (i.e “Raspberry p2,Allo Isolator and HifiBerry dgi+pro”) outside of Roon?


Hi Eric,
my attempts were not successful , so i removed the isolator and went back to the old constellation which worked out well. Its a pity for having purchased the isolator.
regards Jur

Let’s also flag to see if he’s able to shed some light into the darkness…

Hi Jur

isolator works with both master and slave DACs/digital hats , please refer to the manual on how to set it up.

Second the isolator feeds the stage above it (HAT on top) OR can take power from above stage. You cannot do both (feed the hifiberry and feed the isolator in the same time)

At last…what voltage are you using to feed the isolator ? It requires at least 6V (not the usual 5) because an LDO has a voltage drop

Hi Johan,
i use a 6volt power supply. the isolator is configured as a master.

regards Jur

Can you use only one psu ? Power the isolator and isolator will power the above hat with both 5v and 3.3v

Also please take care of sequencing of power…first power the isolator (with hat on top) , then power the RPI I’ve got the same problem with the allo isoloator. I’m using a raspberry pi 3b, allo isolator and the hifiberry digi+ pro. The isolator is configured as master. Without the isolator everything is working fine. With the isolator the only files I can play are 48kHz, 96kHz. When playing a 44.1kHz file the stream is not recognized so no music. I tested it with the spdif out to a bluesound pulse and i2s out to a m2tech evo dac two plus. No difference only 48kHz and 96kHz files can be played. When trying to play a 192kHz file the music gets distorted. This was already the second isolator I tried. The first one had the same problems. When searching on the internet not able to play 192kHz with the isolator is more than once reported: I reported it to allo but they are very slow in reacting to my posts. Probably best to send it back to allo and ask for a refund because I have lost faith in the product.

Hello Bert

sorry about your issues , but the isolator does work until 192Khz on master mode…with tested units.

Unfortunately , on the i2s lines every manufacturer implemented R (resistors) for terminations. Some manufacturers implemented those R without looking into an oscilloscope at the clocks . Basically what I am saying is that isolator outputs a good i2s signal but the termination resistors of your card , while working on a RPI, will not work with the clean output of isolator.

Please contact us and we will do a full refund.

Hello Johan,

I just contacted asking how to return the isolator and get a refund.

With regards,

Bert van der Leest.

I have the same problem it is possible to desolder termination resistors from digi+ pro?