Thank you, but I have two different amplifiers (Aiwa & Onn) and two different pairs of speakers (Panasonic & Sears) available. There is no threat of a cross-connection.

To date, the 6-ohm (Aiwa) system is working fine (with the Sears speakers).

The 4-ohm (Onn) system had unexplained turn-on issues until I returned to its OEM speakers. Aside from its troubles in turning back on after being turned off, it played well through the Panasonic 8-ohm speakers.