Reviews for Quantum Science Audio (QSA) Yellow Entry Level UK Mains Fuse - 3A, 5A & 13 Amp

Having experienced other fuses for the past five years, I was intrigued to try these very high-end fuses. Following a long discussion with Geoff at Future Shop, I made a considerable investment in a Yellow QSA fuse. I took Geoff’s advice and patiently sat through 300 hours of burn-in. The result has been wonderful - hence a further investment in my active speakers.

I loaded my most recent into my high-end mains block, which has my Martin Logan Oddessy plugged into it - wow!! Great separation and detail.

My TV has also improved with improved colour and tones.

Thank you, Geoff, thank you, Future Shop!!

I have been a regular customer of probably the biggest rival to QSA and was very satisfied with their Purple Fuse. I have read an immense about these QSA Fuses, and after exhaustive questioning of Geoff at Futureshop, I took the plunge and bought the “Yellow “. I asked Geoff, who was exceptionally patient in answering all my questions. The two key issues were “burn-in” time and fuse positioning.

I am 242 hours into burn-in of 300 hours. Thanks to Geoff I knew to expect the ebbs of flows of the burn-in process. Both audio and video have improved considerably as I approach the burn-in summit. The picture is sharper and brighter, and the audio is a delight with a wider soundstage and much greater reality.

A great investment which was enhanced by Future Shop’s Geoff!

Thank you yet again Future Shop!

Put this into my Auralic DAC to replace an SR Orange. Big step up in clarity, and the soundstage took about 20 hours to get there. Now that I've gone down the rabbit hole of QSA, I'll swap out all fuses, that's 6 more, but it will be worth it based on what I've already heard.

Probably equivalent to a major component upgrade at half the cost.

I already use RA ultra fuses and thought that they were very good, but this Yellow fuse is extraordinary.

It feeds an extension block through 24 cores into a valve amplifier, and the uplift after the 96-hour burn-in is quite astounding. It is as clear as a bell, with more definition to every instrument, stronger tuneful bass lines and more powerful drumming.

It sounds faster and better with better rhythm and timing. It makes listening to your music even more pleasurable, and I still have a spare fuse to throw in the mix elsewhere.

An essential upgrade.

Having read a few negative comments on various forums about fuses, I was eager for this product to perform in the manner I believed it could.

Happily, it did, and it’s quite obvious the people who say fuses don’t/can’t work have never heard the QSA yellow. Deeper soundstage and better stereo imagery made everything more life-like and natural.

I advise anyone sceptical about fuses to listen to one from QSA and hear for yourself.

It's a great product, thoroughly recommended.

In a previous review, I admitted to having overlooked my preamp in my QSA fuse "odyssey," with my power amp, DAC, and streamer basking in the yellow magic. It was a blunder.

When I gifted it a black fuse, it only accentuated this evident omission. Feeling red-faced and sheepish, I tuned in to the newfound spaciousness that had been "unearthed" in the music I held dear. But a lingering thought persisted - it warranted a yellow fuse... So, without too much self-talk, I took the plunge.

Once I swapped the black for yellow, it was clear that it was no mistake. The separation was nothing short of glorious, and crucially, it didn't overstretch the soundstage. It was akin to space within space.

For those who may question the wisdom of investing £800 in four fuses, let me assure you that it's a decision that I consider worth every penny. The transformation these little yellow fuses have wrought upon my audio setup is nothing short of astonishing. It's as if I've unveiled hidden layers of my favourite music, exposing nuances I never knew existed. If your setup has a preamp, don't ignore it. Go on, spoil it rotten!
Essentially, it's not just a sonic upgrade but a standing ovation-worthy performance.

A fuse (A FUSE!); how can a fuse possibly make a difference? I have no idea HOW it does, I just know that it HAS done - like, a LOT!

After a lengthy phone discussion with the rather brilliant (and knowledgeable) Mark from the Future Shop team, he advised starting off with it on my power amp, which I did.

It's difficult to describe the sound, but here goes: the sound almost instantly changed to appear more "real", more present and less like a recording. Everything is more defined and more articulate in its presentation.

With my mind fairly blown away, I then started swapping the fuse around between my remaining three components - the streamer, DAC and preamp - and found that the next "best" improvement was on the streamer (I have an Ever Solo DMP A6), which opened up the soundstage in the most glorious way. So much so that a week later, I was on the phone again with Mark, ordering my second yellow fuse for said streamer.

As I said, I have no idea why and certainly not how a fuse can have such a profound effect on my system. I just know that it has.

Is £200 a lot for a fuse? Well, yes and no. If you haven't experienced its effect, then (possibly) yes, it could appear absurd. If you have experienced the difference, though, as I have, then I would strongly argue that it's a "small" price to pay.

Great improvement in the quality of my system. I am spending more time listening. A great product.

I bought this to place at the front of my system in the Isotek Evo3 Sirius mains conditioner plug. All my gear is then plugged into the Sirius.

There was an instant improvement in all aspects of the sound, even though I already had SR Purple fuses feeding my streamer, DAC and Amp. This shows that maybe getting the right fuse at the head of the chain is the place to start.

It also significantly improved the performance of my AV equipment. It’s like I’ve upgraded my OLED tv. If you can afford it…buy it!

When you first change the fuses out, it sounds huge, but the details are a bit lost and unrefined. Ten hours in, the bass decreases, and it's a really wonky journey sound-wise until 80 hours which is when it starts stabilizing. The burn-in stopped around 185 hours, and when these were finished, I got the most balanced sound I've heard in any setup.

Nothing sounds out of place vocals and instruments are as loud as each other.