Are A/V receivers digital?

Do A/V receivers convert analog input signals to digital, process them, and reconvert to analog? Can any A/V receiver keep the signal analog?

I ask this because if receivers always convert to digital, as I suspect, all A/V receivers would harm analog signals from SACD and DVD-Audio players. If the receivers can't handle 96/24, they would harm the signal from 96/24 DAD discs as well. Hopefully the receivers with 5.1 inputs keep the signal analog through this input.
As understand it;all the sacd players must be used from the analog outs, on sacd discs.The older pro logic receivers took a signal from the anolog inputs and convereted it to dig. to enable it to do signal processing. That is why you buy a processor in the first place.Yes,years ago Lazer discs were in analog (70's early 80s).The sound quality went up a bunch when the discs were pressed in dig. Then the ld players started coming out with a coax dig out. This allowed the use of a 2 ch outboard dac,before the signal went into your pro logic processor.---Also an improvment. Once DD & DTS came out, aLL digital processors accepted dig. input from the ld or dvd player-----Better yet! No, older analog lds aren't as good as their dig. counterparts.Ok, now what was the question?
All A/V receivers have the ability to convert an incoming analog signal to digital, process it, and convert it back to analog. Some do so to ALL incoming analog signals. Others have analog "pass-through" capability. In short, if you want to be able to keep the analog output of a source device in the analog domain all the way to the speakers but need/want and A/V receiver in the chain, you can accomplish it by carefully choosing an A/V receiver that has this capability, since not all do.
The Denon AV receivers have the ability to pass through analog signals without coverting to digital. They call it "Direct" mode, and it's selectable on the unit and remote.

Hope this helps!
Most A/V receivers and pre/pros convert analog signals to digital for processing, then convert back to analog. Depending on the brand, some have separate circuits that are straight analog (one example is Bryston's SP-1, which has both DSP and pure analog circuits). For vinyl lovers, lack of a pure analog circuit presents a dilemma, since the intent is keep the analog signal "pure". On the other hand, I have a large LP collection, good TT, etc., and my pre/pro
converts all signals to digital for processing. If the analog signal from my LP's is being degraded by the D-A-D conversion process, it is not enough that I find it objectionable.
Not all A/V receivers are digital. Those with AC-3 and DTS are digital. The old Dolby theatre technology is not digital (Pro-logic).