This the one I got. It goes up to 16ft. https://www.amazon.com/dp/B07S1CGQ9Z/ref=cm_sw_r_cp_apa_fabc_W8K4FbZNS9FX9?_encoding=UTF8&psc=1

I’ve had good luck with Zeskit on Amazon. They’re certified and you can scan the box with your phone. I’ve tested it, I get 4k120 on PS5.

Zeskit Cables

I know you said cheapest, but you also said "will last".

Do you really need 50'? Or is that giving you some extra distance?

I've had very good results from Zeskit, even purchasing them to replace old "quality" cables that just weren't cutting it.

https://www.amazon.com/Zeskit-Optical-48Gbps-Compatible-Samsung/dp/B09MMS2B1B

33' - $100

49' - $150

65' - $200

Of note, the above listing doesn't contain all of Zeskit's marketing materials in the listing for whatever reason, here is a listing that has their marketing information -

https://www.amazon.com/48Gbps-Compatible-Netflix-Playstation-Samsung/dp/B07S1CGQ9Z

Note that it is thorough, and identifies why their product is a quality product. Comparing it to the Ruipro listings I would purchase the Zeskit.

Those cables aren't certified. I know this because I bought a set a couple weeks ago.

Get something like this instead:

https://www.amazon.com/dp/B07S1CGQ9Z?ref=nb_sb_ss_w_as-reorder-t1_k0_1_5&amp=&crid=1VZIWL2OR8GG9&amp=&sprefix=zeski

Also, in your Apple TV picture, have you tried enabling Dolby Vision?

Throw away the cheap Amazon HDMI cable and just get these, its all I use on my 635.

​

https://www.amazon.com/gp/product/B07S1CGQ9Z/

• 48Gbps bandwidth for latest features HDR, HDCP 2.2 & 2.3, DTS:X, Dolby Atmos, Dolby Vision
• 8K60, 4K120 & up to 10K resolution, Dynamic HDR, eARC, ALLM, QFT, QMS, VRR

Do not buy Audioquest cables, they are a massive rip off. You can get Ultra Certified cables on Amazon that meet the same specifications for under $20.

https://www.amazon.com/dp/B07S1CGQ9Z/

https://www.amazon.com/dp/B08X6C4MY9/

https://www.amazon.com/dp/B0919GTQS9/

https://www.amazon.com/dp/B09VBWRQM8/

https://www.amazon.com/dp/B08SLR3HW9/

As far as I know this is the only " certified" hdmi 2.1 cable on the market. It's a little pricey but it's worth a shot. My previous cable worked fine with 4k @120 but would not let me send and hdr signal over it for some reason this cable fixed that problem..

https://www.amazon.com/dp/B07S1CGQ9Z/ref=cm_sw_r_em_apa_fabc_si28FbRQTK3V7

Denon AVR-S750H

Ditch the optical, and use HDMI eARC. May seem weird - but optical isn't as good as HDMI eARC. Optical wont do anything more the 5.1 I think. So it may not do FLAC quality either. Give it whirl. Edit; you'll need a good cable like this: https://smile.amazon.com/gp/product/B07S1CGQ9Z/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1