Fiio M11S Focal Bathys

Dear Roon users,

When I listen to Roon, I mostly use headphones and my Fiio m11s DAP. I have a Grado sr325x, a Hifiman He400se, a Fiio ft3, but I also have a Focal Bathys, that I use wirelessly on the train, connected to my iphone. The Bathys can also be connected with a USB wire or a 3.5 jack cable. In the first case, the internal DAC of the Bathys is activated.

Now I tried to connect the Bathys with a 3.5 jack cable to my Fiio, and that works perfectly, the internal DAC of the Bathys is not active I think. When I connect the Bathys to the Fiio with the USB cable in USB-DAC-mode, I hear strange “hiccups” listening to Roon (not when listening to Qobuz through the Qobuz app), perhaps because the two DAC’s interfere? Roon Arc works fine though, but in the signal path I notice a downsampling…

What would be the best way to listen to Roon using the Bathys?

Kind regards,


The Focal Bathys offer so many connection options that it is difficult to say which is best. In addition there are almost as many different ways to consider what is “best”.

For me the best way to listen to Roon (not Roon ARC, which has different challenges, like getting ARC to work without burning through the mobile device’s battery) is to use my iPhone, working as a Roon endpoint, a lightning to USB OTG cable and the Bathys in USB mode. When I’m on the go I use the iPhone, a lightning to USB OTG cable and the Bathys in USB mode and listen to either PlexAmp, Qobuz or Tidal, works great!

I tend not to use the Bathys with my M11Plus since the M11Plus has a very good internal DAC and has lots of power to drive most headphones. However if you do want to use the Bathys with the M11S then you can use them in one of three ways:

via Bluetooth

via the 3.5mm headphone outlet, when used in this mode the Bathys must be turned on and the internal DAC is ACTIVE but the Bluetooth is disabled.

via the USB outlet with the Bathys set in USB mode and the M11Plus (which is the model that I own) not in USB DAC mode. I believe when used this way the internal DAC of the M11Plus is bypassed and the digital output is sent directly to the Bathys. This connection method should have the least amount of ADC/DAC conversions with just the Bathys’ internal DAC doing the conversion to analog.

I know that all this can be confusing but I tried to explain things as clearly as I could. Give all three methods a try and decide which one works best for you.

First can you distinguish if you’re using ARC or Roon here or a combination of both?

For Roon are you using the FiiO Roon App to use its Roon Ready output when using it with the USB connection to the Baths? It’s an easy mistake to add Roon Remote and use its native output which will show as FiiO M11 but this isn’t bit perfect an is not what should be used with the M11 or you using the basic Android implementation and it will resampe. Any hiccups using Roon Ready are likey to do with FiiO and not Roon.

In ARC have you enabled USB dac mode in settings as this will be needed for the Bathy to work. ARC on current DAPs is not bit perfect unless using an external USB dac as Roon thinks it’s a basic Android device and resamples.

Thanks for your advice!