There is no line out on a Sonos Amp. Only speaker outputs. 

So you’d want to set it up as if you were using an amplifier to send a signal to another amplifier without using a line level output, i.e. highly not recommended.

Not sure what Sonos is supposed to do to satisfy your needs, with the international chip shortage. I wouldn’t think they’re overly excited about not having product to sell to you immediately, either.  

 Nor do I think I understand what a 70 volt system really is, so perhaps this response misses the mark in some ways. 

Look for a speaker to line level converter - usually a cheap little box of tricks that does the job, though I don't know if it takes away from sound quality at all - never having used one.

My topic was written out of frustration - mainly because Sonos cancelled ALL orders, raised the price $100 and has been very “cold-shouldered”.  At first, I did accept the fact there is a chip shortage, supply shortage, etc.  But Sonos is still a multi-million dollar company raking in millions in profits while integrators and installers are losing money simply because they have to say no to jobs where customers demand Sonos products.  It’s happening all over and the frustrations are mounting higher and higher so I apologize for that.  

I 100% understand how the product works, but it would be in Sonos’s best interest to endorse a work-around so we can continue to successfully work with their products while waiting for supplies hence why I came here to post this topic.  

Thank you Kumar for the suggestion - I will give it a test run.  

With a digital amp, switch mode PSU and no grounding I would be very wary of trying a speaker to line level converter. On a traditional amp with a big transformer, no problem.