Fuses that matter.

The following is my experience replacing the standard fuses in my integrated amplifier with Hifi Supreme Tuning Fuses. The amp is an ARS-Sonum Filarmonia. It has maximum output power of 30 watts RMS per channel at 8 ohms. Its output stage uses a pair of E34L pentodes per channel, in push-pull configuration. It is an outstanding amp paired with Merlin Master VSM's.

There are three fuses. The main power fuse is a slow-blow 4 amp, and the two internal fuses are also slow-blow rated at 500 mA.

I initially purchased only the main power fuse, as I had heard that it has the most dramatic impact. From the moment I replaced the stock fuse, the improvement was clear and continued to improve over the next week. With that success, I decided to spring for the two internal fuses. Unlike the immediate improvement with the power fuse, my initial response to the new internal fuses was, "Wretched!" It was so bad that I immediately shut the amp down, took the tubes out, disconnected all cables, opened up the amp and switched the direction of the fuses. I believe that this improved things slightly. But still it was virtually unlistenable for the first ten hours. By 15 hours, it had started to relax a little, although still extremely congested. By 20 hours it was just barely starting to sing.

I've now got about 30 hours on these new fuses and they're sounding pretty darn good. At this point I would say that they are a definite improvement over the stock fuses. Primarily, the soundstage seems to be more clearly defined. I have more of a sense of the depth and boundaries of the original recording environment. Instruments are also more realistically "shaped."

This is perhaps the most dramatic burn-in phase of any new component I've added to my system: from wretched to pretty spectacular. Maybe it's the 99% silver wire. I am expecting continued improvement through 100 hrs. based on what I've read.

I'm writing this for anyone who has purchased these and have not had the patience to let them burn in. I was tempted to give up at 10 hours, given my experience with the immediate improvement with the main power fuse. I suppose, however, this makes some sense. I have very little technical knowledge, but the current running through the signal path must be much lower than the current running through the main power fuse, hence the longer burn-in time??

It always amazes me that manufacturers do not state clearly and unequivocally that their product WILL sound inferior until after XX hours of playing time. I bet that plenty of "non-believers" in the burn-in phenomenon have judged products inferior before giving them a fighting chance.

Turboglo,

I can't think of a single audio component I've ever owned or listened to that didn't sound better after a few days of continuous use. Witness how reviewers at shows who return to rooms usually notice improvements.

I agree that it may be counter intuitive to some and that the Hifi Tuning fuses require significant break in time. Too many audiophiles try out equipment like they choose their beer; quickly. However, the ears aren't the tongue and properly converting electricity into music is still a mysterious process.

Turboglo and Vhiner, most reviewers don't have the benefit of manufacturers coming to their listening room and setting up already brokenin equipment and setting the room to optimize their equipment. And, of course, those who get this benefit may be listening to "special" pieces.

I just notified a manufacturer that I know the very special Urushi caps he and others use, take hundreds of hours to break in and that I would probably need a month and a half's access to his component.

I am also now using exceptional interconnects and speaker wires that may take 1000 hours of use to reach their best and may take two days to recover from being moved from one component to another. How I would love a piece that sounded exactly the same at 15 minutes and two years.

slow-blow vs fast-blo?

We all know fuses do make a difference (at least those commenting here). And I presume most of us -when we say fuse upgrade- are buying slow-blo.

But what if its fast-blo fuses that are best? Putting aside what the manual says, has anyone compared both types of the same value and brand?

No doubt some boutique fuse manufacturers are just supplying the same product for both fast and slow, but that's another story.

"No doubt some boutique fuse manufacturers are just supplying the same product for both fast and slow, but that's another story." On what are you basing that assumption? One might replace a fast blow fuse, with a time delay type, BUT- it would be VERY foolish, to do the opposite. ie: Generally; time delay is necessary, to allow a power supply's caps to charge. Rail or B+ fuses need to respond immediately, should a downstream device short/draw high current, or serious damage can occur elsewhere in the unit's circuitry.