DAC won't lock on to Bluetooth receiver. Any ideas why?

[Chr1]

I am having a problem getting my Tannoy TDX-1 system controller to lock on to my Xduoo XQ-50 Pro Bluetooth receiver for some reason. Connection is via digital coax. The Xduoo works fine when connected to my AVR via coax, so I think that the problem is with the TDX-1. It has a green LED which is "on" when the internal DAC has locked on to an incoming signal. It's not locking on for some reason and continues to flash, rather than remain solid.

I am wondering if it could be the output level of the Xduoo. The manual states that it is: "0.5Vp-p" via coaxial.
As the TDX-1 is a pro-audio system controller, I'm wondering if it expects a higher voltage signal or something. Being a digital signal, this seems very unlikely and I use it, connected the same way with a Cambridge Audio NP-30, which is a regular consumer/hifi streamer, and it works fine. Definitely not a cable issue.
Anyway, at this point I am at a bit of a loss.
Have attached both manuals.
Any help most appreciated.

 

[Roland68]

I am having a problem getting my Tannoy TDX-1 system controller to lock on to my Xduoo XQ-50 Pro Bluetooth receiver for some reason. Connection is via digital coax. The Xduoo works fine when connected to my AVR via coax, so I think that the problem is with the TDX-1. It has a green LED which is "on" when the internal DAC has locked on to an incoming signal. It's not locking on for some reason and continues to flash, rather than remain solid.

I am wondering if it could be the output level of the Xduoo. The manual states that it is: "0.5Vp-p" via coaxial.
As the TDX-1 is a pro-audio system controller, I'm wondering if it expects a higher voltage signal or something. Being a digital signal, this seems very unlikely and I use it, connected the same way with a Cambridge Audio NP-30, which is a regular consumer/hifi streamer, and it works fine. Definitely not a cable issue.
Anyway, at this point I am at a bit of a loss.
Have attached both manuals.
Any help most appreciated.

If the TDX-1 works via the digital connection with the Cambridge Audio NP-30, then you have a good starting point for testing and know that the TDX-1 is working.

Have you considered that the TDX-1 only accepts 44.1 and 48 kHz inputs? You should check this on the Xduoo XQ-50 Pro's display.
Do you have to activate the respective output on the Xduoo XQ-50 Pro?
The CS8406 transceiver chip in the Xduoo XQ-50 Pro isn't the most reliable chip for SPDIF output; that could also be the reason.

 

[Chr1]

Thanks. Yes, I have checked the Xduoo is outputting either 44.1 or 48khz. It doesn't need to be activated. It also works fine when connected to the coax input of my Pioneer AVR, which is why I don't understand why it isn't working with the TDX-1.