[PROBLEM] New user - routing/monitoring sound card input as source

[johnr]

Hi all,

I'm linking up an RPi to an old valve radio. I'm trying a few packages and Moode is one of them.

I'm using the RPi for other things apart from music (ie, to turn the radio on/off via a relay etc) and running an LCD screen.

But one of my preferred sources of music is a Google Chromecast. I have Google Home devices and I like to be able to say 'Hey Google, play X on Y' etc. I will possibly end up using this as much as an other source. 

I've built a two input mixer that takes two stereo sources, sums them down to mono (it's a mono radio), amplifies the signal a bit and them connects to the input on the radio.

So... I could just put the RPi in to one of the inputs. and the Chromecast into the other. But what I'd really like to do - I think - is output the Chromecast into the RPi input and then route it to the output.Then I can turn that on or off - effectively muting the Chromecast to prevent any overlap of music coming out at the same time - although the mixer would cope with that, I'd rather avoid it.

I'm using a cheap USB audio device with a 'mic' input (mono) and a stereo output. The mono input isn't a problem because, as I said, the radio is mono anyway. 

Is there a simple way using Moode to route, or monitor, the input of the usb device to the output? 

Hope this makes sense. Please ask if not and I will try to explain better.

Thanks
John