You can use A and B at the same time. You can also use A in one room and B in another room.

Yes you can

Yes

Any receiver that has RCA audio inputs can handle a turntable with standard RCA output cables.

Most receivers are compatible...

Yes, you can hook up a turn table to this receiver.

You can use typical speaker wire for the connections. The little red and black knobs loosen and reveal a slot to slide in stripped-end bare wire of any standard speaker wires. There is a different kind of connector you can use, but that is just an option.

Might be quicker and cheaper to just by appropriate speaker jack rather to to mod.

No sir you can't you have to buy an active sub or mod your current one with a sub amplifier plate

Yes you can or yes it will

Yes it is -- the two "extra" channels can be utilized in a 5.1 bi-amp configuration.

Yes.

Recommend you download the full, 269 Page Operating Manual. (just Google the Model number). I still trying to decipher all the different speaker arrangements and sound options. I just bought more speakers and plan to spend a couple days experimenting.

Don't be cheap, but all 9 speakers is worth it. .if you have a large room, if not hook up the front and rear skip the middle surround

Either you have the wires connected right on the reciever side and not the speaker side or the reciever is too powerful for the speakers

Check your wiring, you may have a slow leak to ground.

No you cannot. It's extremely rare that you will find electronics made for the American market with that feature. What you could do is get a step-down transformer for it.

No, you cannot adjust the voltage on this unit.

No.

I used a 2015 chromecast model with my receiver and it works as it is supposed to, no problems so far with compatibily, just make sure you use the external ac/dc adapter for the chromecast instead of the Onkyo usb port.

Yes you can but I wouldn't recommend it. The unit only goes down to 4ohms, anything below that will push it quite a bit. It will heat up way too fast and turn it self off as a result - not a good experience if you're watching a movie. Plus, it just might not last long enough.

You can technically use any ohm speaker you wish, but you'll run the risk of damage to the speaker if you connect it to this receiver.

If you absolutely must use them (because you can't afford a new set or for other reasons) then I suggest you hook them up with receiver off and keep volume all the way down, then SLOWLY turn volume up to comfortable listening level. The moment you hear any distortion or popping, turn the volume down and if any noise continues, turn the receiver off and don't use those speakers

Possibly if it has blue tooth capabilities. But otherwise you will need a receiving base to plug into an audio input on the receiver.

You can probably buy a kit to accomplish this. I know such kits exist for subwoofers.