Do Fuses make a difference ib sound?

Great thread and a lot of good points were already made...

1. Fuses are directional. True in my experience. 

2. The fuse maker explanations defy logic. True to me anyway.

3. Blind AB tests are really hard to do and moving equipment around to get to the fuse in back can also make a small difference.

4. Why not try them from TCC to see for yourself? If you like, its a small investment relative to your system. 

In my experience fuses do make a difference once they’ve had 200+ hours of break in. Better ones make more of a difference. I use Synergistic and Audio Magic fuses and they typically remove some harshness while allowing for smoother, more detailed presentation. 

Why do they work? I dunno, but they do something. Obvious end-of-the-chain ideas are the little screen right at the end of a faucet that changes the way the water comes out after being in miles of pipe or having people line up to enter a building instead of all rushing in. I truly can’t imagine why fuses work, but to me they do. Maybe it is the fairy dust. 

Funny, but my 2 cents.

I used to own a Bryston BDA3 DAC.  For whatever reason, I decided to try, on promise of a full refund ( not credit ), a Synergistic Research Orange Fuse. I was very skeptical.  The DAC was well broken in, I had used it for years. My wife and I both agreed, that keeping it made sense, as the music sounded better!  It was quite a few years ago, I don't remember the 'details', but, we kept it.
Now, I eventually upgraded to a new DAC, and sold the BDA3 to a guy who used to own 2 of these DACs, BDA3.  He decided to buy mine, with the fuse, to see if it sounded different / better or the same. 
He told me that of the 3 Bryston BDA3 dacs he owned, mine with the SR Orange fuse sounded the best. 
I really don't understand it, but, in my opinion, it made a difference, and we liked it. 

To those whose response is (paraphrasing) I know electronics and circuitry and can tell you they don’t make a difference…. Again, as mentioned in a different thread, you can’t “think” your way through a discussion of audible changes. The only tools appropriate to evaluate are on the sides of your face. If you haven’t listened to a product under discussion, your opinion is less than helpful. 
 

If curious, try the product in your system with your ears.  If you hear and like a change, buy em. If not, don’t. I heard a difference, I bought some. The change didn’t knock my socks off, but I liked it and bought em. 
 

Kent with Pass Labs, I’m aware PL doesn’t support modifications, so I have NOT opened those boxes!  My experience relates to other gear. 🤓

One way of playing with fuse results is used (as I mentioned earlier), but also the QSA black. At $28-30, could be a fun experiment. Start with your pre or amp. I think I heard a difference… but who knows. I then moved to the used SR orange for all my main components and put the QSA in my Aurender, adding one for my sub. All in I have $270 invested in 6 fuses, a relatively low amount. 
Gemini recommendation: 

Because the QSA Black sits at the bottom of their line, it is a relatively low-risk experiment compared to their upper-tier colored fuses, which scale into thousands of dollars.

If your digital front end, source components, or amplification are highly optimized and you enjoy fine-tuning the final fractions of a percent of system performance, it is a fun trial to see if your ears detect a change in the noise floor. However, if you are looking for a massive, undeniable shift in tonal balance or power, investing that money toward room treatment, speaker positioning, or clean power delivery at the wall will always yield a more predictable, measurable return.

Audio magic thier top fuses I find $300 each a bit pricy ,but after 175 hours a more natural presentation and like them better then the $600 synergistic fuses overall 

Alfred gives you 30 days to audition for a full refund .