How Big of a Difference?

+1 for Morrow, that's where I started my cable journey due to the gaurantee, but I bet others (Blue jean, wireworld, anticables) could also deliver.

For me, power cables and speaker cables make the most discernable difference, that and using XLRs vs RCAs.  I was shocked at the impact of power cables esp for amp and pre.

Confirmation bias story - when I decided to up my speaker cable game, I posted on the Thiel user's post for advice and happily took Eric Squire's advice and went after Acoustic Zen Hologram, used market for reasons described above.  First offer I made was to a guy using these cables in a Magico/Aesthetix system with Audio Note DAC, way way out of my league.  He accepted my offer, but then reneged bc he couldn't handle the SQ with different cables!  I found another seller and happily hooked up my new cables to my modest system and was happy with the improvement, discernable for sure but not certain I'd be able to tell a difference 100/100 times in a blind comparison test, so have always wondered how much of this is confirmation bias.  But more than anything this experience added to my amazement that power cables seemed to have more of an impact.  But then I remembered I went from stock power cords to $300 used Cardas, and the speaker cable change was from a lower tier Audioquest to the AZs.  Don't get me wrong, I'm sticking with the AZs, but I think this illustrates the fact that you gotta try for yourself and see, and good luck filtering out the CB!

Re digital cables, not sure if I've been able to confidently tell a difference.

All that being said, the weak link in my system might be the long run of AQ Cascade xlrs from pre to amp, I need a good 15-18' and haven't come to terms with spending the same amount of $$$$ on cable as a component.  Might have to start a discussion with that question.

Once you get tired of listening to cables, get some tube gear and start swapping out tubes.  To me these are great ways to exercise and improve your listening skills.

IF you have money to burn through, the best cables I have heard were Goetz and Western Electric's or Dueland's imitations which may sound even better than the originals. 50 years ago Western Electric cables delivered clear voices from coast to coast. You could, assuming that you knew the person at the other end, easily discern who you were speaking to through thousands of miles of cable.. Goetz cables need to be zobeled to ensure that your amp doesn’t go into oscillation at frequencies above your ability to hear it and burn up. You can't be sure that aresistor or capacitor lead won't break, and you won't likely even know that your amp is in trouble until it's too late. They are now selling counterfeit Western Union cable, so I have gone to Dueland for all my new cables. Some will warn you that the tin will create a diode effect. I don't care if it does, cables present their own load to the speaker, hence Goetz cable's capacitance burns up some amps. Regardless of what they claim I've tried home made concoctions, and expensive cables and most just made things worse. The Dueland cables just work, and I can't explain the theory because getting the proper resistance, capacitance, and inductance, crunching those numbers ignores the amp and speakers which are also part of the circuit. As the cables appear to perform regardless of the circuit I just don't care about the why, I am just thrilled to have cables that work. Perhaps I should get the Dueland cables for the speakers, but my old Western Electric cables are the real thing, and I am content with them as speaker cables and Dueland for all my ICs.

12 gauge solid occ copper for speaker cables +1

To answer your question, based on my personal experience, Yes cables make a difference.  For the sake of comparison, I run Tidal on a crappy old Windows based laptop. This feeds a Schiit Yiggy ( Gen 1 ), to a Rogue pre and a Had Inspire. My speakers are first generation Zu Omens. So our front ends are very close. I run a USB cable to the Yiggy. First I used a cheap cable from my old camera. Then an Audioquest Cinnamon. I had a noticeable improvement. After a couple months I tried a Cardas Clear usb, and again a noticeable improvement. So comparing the Cardas to the cheap camera cable there’s a significant improvement. As far as speaker cables I’ve always used banana connectors. First I used 12 ga bulk speaker cable in copper then silver. Next I used Anti Cables level 3, and now I use Morrow level 4.  There was an annoying brightness with the silver 12 ga. From the 12 ga copper to Anti Cables to Morrow 4 I experienced an improvement each time. My opinion is that in my system silver cables are too bright. The Morrows bettered the Anti Cables with better sound stage, but tonality was about the same. In regards to power, I run Morrow Level 4 and use a Richard Gray 1200 power filter. I never used the stock power cords. I started with a mixture of Pangea, Silnote and a digital specific cord. All of these cords had a price point of $100 Ea. So with the Richard Gray already in place, I really didn’t notice an improvement adding the Richard Gray or my Current Morrow cords. However at this point I swapped the heavy power cord that came with the Gray for a Shunyata Venom HC 20 amp cord. That made a very noticeable improvement in the whole system. I also have Hubble medical outlets. For a sound quality comparison please consider this. I have a modded Thorens TT with a Grado Prestige cartridge. When I spin my best vinyl and do an A-B with Tidal, the sound from my crappy laptop is very close to the turntable. Now keep in mind this is limited to specific recordings like Pink Floyd/ DSOTM, Supertramp/ Crime Of the Century, Alice In Chains/ MTV Unplugged, to name a few. This does not apply to all my vinyl Vs streaming Tidal. I’ve also done considerable tube rolling and have a 15x18 room with a vaulted ceiling and heavy shag carpet, heavy drapes and large fabric covered  furniture. So my room is fairly forgiving with my system. You have nice gear and obviously know what your doing, so I assume you have equal quality speakers that are properly placed. So I’m of the opinion that all cables matter, but some make only a slight difference. I’m cost driven, so I’ve never tried the expensive stuff, but I’ve tried to match the level of my gear. People that have helped me with my system are of the opinion that any big improvement would come at a significant cost. One of the other things that I noticed is the very long break-in time  Morrow cables take, especially the interconnects . So this was my experience and my suggestion is that you take advantage of the free trial many manufacturers offer and remember to allow for break-in time.  My Morrow IC’s took 400 hours. Happy Listening and please feel free to PM if you want to chat. Happy Listening, Mike B. 

In my experience, with some blind testing, yes, speaker cables make a difference. No it's not always good and always too expensive.