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

Having bought a couple of QSA light-blue fuses, which significantly improved my overall sound, I decided to upgrade the fuse powering my Russ Andrews mains block to a 13-amp yellow fuse.

In short, wow! What a huge leap after running in the fuse became open, detailed and natural. What astonished me the most was how utterly neutral and analogue it sounds; the voices have a faultless quality. There is also so much more treble energy, as if a veil had been obscuring the sound; despite this, there is not a hint of brightness or harshness.

Dynamics are astonishing, with such a low noise floor, the tiniest details have become much clearer. I'm noticing details I've never heard before. For the price, the yellow fuse is an absolute bargain, 10 out of 10.

My system comprises the Creek 100cd and Stack Audio CS1 anti-vibration feet for the Creek CD. This is fed as a transport to the Chord Mojo 2 DAC, to Audeze LCD2 planar magnetic headphones, and to an Arcam a38 amp and Creek loudspeakers. Most of my listening is done on headphones again.

Thank you to Futureshop for the advice and excellent service.

Now I have to save up for my next yellow fuse. Yes, they are that good

Installed this new fuse along with a Furutech Review Furutech FP-S032N Alpha Nano-OFC Power Cable FI-1363(G) to FI-28(G) 1.5m Ex-Demo. As supplied by Futureshop with a 96-hour burn-in.

This was to replace the Rega power cord connected to my Rega Aethos amplifier. Both represented a significant upgrade over the Rega cable, with improvements noted by other reviewers. As others have stated, you need to be patient with the further burn-in and the sound will vary throughout the process.

Highly recommended, I shall be trying more on my power leads to my Isotek Aquarius power conditioner.

Top service from Futureshop as always.

System: Rose 150B Streamer, Arcam AVR 550, JBL HD3600 Speakers.

I called Mark just for some recommendations. I felt my system wasn't engaging enough, and the sound could be clearer. He recommended the Yellow Entry Fuse at £200. I thought it sounded a lot, but he said that is the minimum I should go for.

I read the reviews and did some research, and ordered one about 3 weeks later, opting for 24 burn-in. My initial thoughts. The vocals are more natural, and the instruments are more obvious. Slight clearer sound.
It wasn't a huge improvement, but it was definitely immediate.

Now I have only had it for a short while, and other reviewers said it takes some time to get fully burnt in, so I'm excited to see it improve further over the following weeks.

Based on the positive experience with QSA and Future Shop. I will be buying further 'Tweaks' in the coming weeks.

From the moment I fitted the QSA Yellow fuse straight from the box, I was impressed by its transparency and sparkle, but it wasn't overly bright, as everyone seems to be commenting on. I thought the treble was very open at the top! As the days progressed, the more natural my system sounded, with deep, deep Bass and a wonderful, wide sound, but not as deep as I would've liked...That took another 2 or 3 days to manifest itself!

Some folk are also commenting on the comparison of Synergistic's Purple fuse.... NO NO NO the QSA is on another level in my humble opinion.

My system is pretty revealing, including German Physiks speakers/Edge amplification/Ayre C5xeMP sacd player/Acoustic Signature TT and Shunyata/Gutwire and Cardas cabling. I am now trying to persuade my Mrs that we need a Violet or even possibly an Orange(but with no juice)fuse to replace another Synergistic fuse, this time a Pink one.

I had a yellow QSA mains plug fuse for Christmas and have just popped it into my Chord Epic mains cable feeding my Luxman L509x amp, one song in with a cold amp and no running in on the fuse, I am hooked, awesome upgrade.

Needless to say, I will be buying more very soon for my other components/systems.

I was very sceptical about the benefits of these fuses, as they seem to defy logic on a value-for-money and science basis. How wrong I was. They have taken my system to a new level in all sonic parameters.

The ‘proof of the pudding’, I am buying more.

Wow… the difference this little yellow fuse makes it’s unbelievable. Don’t take my word for it, just try it for yourself.

Purchased on the recommendation of Mark of Future Sound, I was a little sceptical at first, the fuse is inserted in the plug of my recently purchased Exposure 5010 preamp, the hub of my audio system. The fuse had already received the four days of burning in at Future Shop, and listening carefully to the playback of some of my favourite CDS at first, any difference was hard to detect. Four days onwards, and I did start to notice a tad more clarity and bass control. These fuses appear to benefit from even more burn-in time, some reviewers stating 200 hours makes a difference.

An audiophile friend visited me for a listening session, and one standout CD that demonstrates the benefits of the yellow fuse is Goodbye (2019 remaster) by Ulrich Schnauss. This extremely multilayered album now sounds even more distinctive, and instrumentation separation is more apparent.

I have found that this fuse significantly improved the sound in my system. Stereo imaging in particular was improved. Needs time to burn in. I perceive cumulative improvements with multiple fuses in the chain.

I have found a significant improvement in stereo imaging and detail from my amplifier with the Yellow fuse in a mains cable. The best improvement was found when the fuse in the amplifier fuse holder and the fuse in my mains block were also changed.

I think the fuse does need time to burn in, possibly 100hrs or more.

Personally, I prefer the sound of the Yellow fuse to that of my previous Synergistic Research Orange fuse.