We would like to connect the Sonos CONNECT stereo output to the mono input of common 70V commercial sound amplifiers.. specifically the Bosch PLE-1P240 (https://us.boschsecurity.com/en/products/publicaddressandvoicealar/pacommercialsoundandemerg/plenaeasyline/ple1pxx0usplenaamplifier/ple1pxx0usplenaamplifier_36847). Our question is can the L/R analog output of the CONNECT be combined in parallel/phase using a simple Y-cord arrangement? Or would one need to add a few 1kΩ resistors in series to sum them together (vs 'shorting' together). I wish the CONNECT had an monaural analog output!! And what about sensitivity? Most home audio is -10dBV, whereas pro equipment is typically +4dBU. (The Bosch has input sensitivity of 1Vrms for full output so falls somewhere in between.)