Optical will pass lossy audio; eARC will pass lossless audio. If you're not noticing a difference using optical instead of eARC, don't worry about it. If you're noticing a difference, try AppleTV --> HDMI to AVR --> HDMI to TV.

 

Apple TV HDMI to AVR , AVR HDMI to TV is causing my lip sync issues

 

If you aren’t using the TV apps or if you don’t have any devices plugged into the TV that need to pass sound, than you don’t need ARC. Have you tried plugging the HDMI cable into a non-ARC HDMI input on the TV? Also try turning off any sound enhancements or CEC in the TV also.

 

Apple TV HDMI to AVR , AVR HDMI to TV is causing my lip sync issues

You wrote:

Fighting lip sync issues with EARC and when I use optical from my Bravia 7 to my Yamaha RX-V6A it is gone.
...
Setting up my new loft HT and as of now I’m appletv , Bravia 9 , Marantz NR 1609 and having same issue into a stereo 2.1 set up. ...

Both scenarios suggested AppleTV connected to TV, with eARC or optical connection to AVR for audio.

If you're actually going AppleTV --> HDMI to AVR --> HDMI to TV, eARC is not involved, and the AVR should have a menu option that allows you to adjust delay / lip sync.

I hope you're able to get it sorted out.

 

Yes , sorry for confusion. I have appletv HDMI to AVR, HDMI to TV. Lip synch delay setting works but for whatever reason not the same on different apps. Example , Spectrum TV I manually set it , then go to say Netflix and I have to change it again. I know I can probably do a deep dive into the appletv settings but for sake of this thread I just want to know will optical give me same sound quality for 5.1 Dolby digital because it has no lip sync issues on my other set up where I plug apple tv hdmi into TV and then optical to AVR , so no hdmi connection at all between tv and AVR

 

for sake of this thread I just want to know will optical give me same sound quality for 5.1 Dolby digital

I detect improvement DD HD/DTS MA/MultiChannel PCM over plain DD.

 

Optical will give you the same sound quality as HDMI if all you are watching is cable TV and streaming apps. Both only use lossy audio (Dolby digital+).
Edit: DD only by optical, not DD+

 

That’s what I’m hoping , thanks. For the price of the cable I’m just going to try it anyway

 

Oops. My bad. as @rekbones said, Dolby digital only, not DD+. Probably doesn’t matter for 5.1 only.

 

Optical won't support DD+. You will get a loss in bandwidth, very likely you won't notice but again you may.

 

For 5.1 streaming it won't matter. Technically E-Arc can do lossless if the source has it. Most streaming services, meaning pretty much all of them, do not use lossless so there is no loss of quality between E-Arc and optical for 5.1.

BTW, have you tried E-ARC where the Apple TV is plugged into the TV and you use E-Arc to get the sound to the receiver from the TV. As mentioned, plugging the Apple TV into the receiver is not using E-Arc.

 

If you let the Apple TV process the audio and send it out as PCM it will probably have lip sync issues. Let the apple TV send audio unprocessed, bypass or bitstream mode, whatever are available.
eARC sends out lip sync info, how much delay are needed for the audio, and the AVR process that info to get lip sync. If your Bravia TV and AVR are set to auto in their lip sync it should automatically adjust the delay depending of what kind of source the TV has to process, if the Apple TV isn't doing any audio delaying by itself, as it can't do if it sends HDMI signals unprocessed.

 

Optical can only do uncompressed 2.1ch. It's also limited to certain Dolby/DTS formats, and anything more than 2.1ch will be compressed.

 

Optical can only do uncompressed 2.1ch

No. It can only carry 2.0 uncompressed (PCM - one or two channels only)
2.1 (denoting a 3rd channel) would be Dolby Digital or DTS and therefore compressed (lossy).
Anything sent via "bitstream" will be "lossy" Dolby Digital or DTS.

 

If YOUR system is receiving PCM Stereo and sending a discrete .1 channel, you have a magic system.

I think you mean that your system is using a subwoofer with a PCM Stereo signal.

Do some searches...

 

You are both correct

A lot of systems take a 2.0 signal PCM and output 2.1, any surround receiver can be configured this way. But there are stereo systems that also have bass management for a subwoofer like a Wiim Amp, Sonos Amp, many stereo receivers or integrated amps.

If the signal is optical and lossless uncompressed PCM it is stereo only. DD and DTS can send only 2.1 material. In fact they are capable of any combination from mono 1.0, to 1.1 mono with a sub, to 5.1 discrete or 6.1 with DD EX or DTS ES. Any of the DD/DTS formats are lossy and compressed.

Back to OP. Optical is fine. I can't think of a video streaming service that uses lossless audio (Dolby True HD, DTS Master Audio or 7.1 PCM). Most use DD or DD+ if using Atmos. If you have music services through your Apple TV then some of those use stereo PCM (Tidal, Qobuz, Apple Music).

Do you have any sources that might have lossless audio, like Blu-ray, Kaleidoscope, or other device? If not, using optical is fine if it works best in your system

Disadvantages of optical are:
1. It won't have on screen volume.
2. The volume will have to controlled with a different remote unless your remote can learn your receiver's remote.

 

A lot of systems take a 2.0 signal PCM and output 2.1, any surround receiver can be configured this way.

To pick nits...

The fact being that PCM over S/PDIF can only be one or two channels. Through the magic of DSP's, bass management, LPF/HPF, whatever/however..... You still only begin with 2 channels and ADD a subwoofer as a compliment. It is a psuedo ".1".

There is no "discrete" .1 channel with PCM over S/PDIF.