In picture 3, what are the words written above and below the two sets of RCA jacks? All I can read is red and black, the rest of those words would be helpful. 

Also, in your first picture, there appear to be a pair of RCA jacks above the clips for the speaker wires. What are these labeled?

It’s entirely possible that this device may not be suitable to connect to a Sonos Port. 

Hi, Thank you for the quick reply.

- I attached pic 3 with the headings readible.

-

The two rca jacks above are the aux in channels - I could connect Sonos to these, to play it on my speakers, but the CDs would not be streamed through the Sonos system. 

I don’t think you can connect to this. The Aux is analogue input only; the only output i can find is the front panel headphone, which is not suitable. 
If you have ripped your cd collection onto digital storage you can access them as a “music library” in a Sonos system. 

I’m of the same opinion. You could conceivably us a Port to stream to this device, using those Aux in ports, but you can’t get any substantial information out of this device.

Thank you again for your frank replies. A related question: are you aware of any converter converting these outputs into regular RCA? Is that possible at all? Thx

I am not, but then I’ve had no reason to even look for one. Have you tried a search in Google?

There are speaker-to-line-level converters, but here we’re talking about something which would also sum the high/low outputs and reverse the frequency split effected by the Panasonic’s crossover. An utterly horrible idea, frankly.

Just toss out the old kit and, if you must play CDs, get a CD/DVD player. Better still, rip the CDs to a network drive and toss them out too.

I’d certainly agree, but was attempting to be sensitive to the OP’s statement:

Please note, that hanging on to my current hifi is an emotional thing, thus changing it is not an option for me.

True, but music is an emotion thing too, and the audio consequences of trying to bodge an ancient mini system into Sonos are, I’m afraid, too unpleasant to contemplate.

I looked up the manual, and its only other output is a headphone jack, which he could use as input for a Port or Connect, but it would probably kill the speakers, also killing the emotional attachment.

Thank you all for your replies! I meant to check every option before coming myself to ratty’s conclusion, that playarounds are “an utterly horrible idea”. (I.e. I also exchanged e-mails with Panasonic support, who diplomatically pointed out, that they do not have any such converter device.)

As I will certainly hang on to my CDS I will most likely end up buying another CD player - and of course never toss out the old one ;)