Hi-Fi Fuses - SNAKE OIL? - or something in it?


There's a lot of chatter about the benefits of those high prices gold plated fuses with silver conductor etc. etc. all over the web and the consensus ranges from FANTASTIC!!! to much more subtle observations.

It makes sense to me, epseically in light of spending lots of $$$ on good power cables, that having a skinny piece of aluminum conductor in a glass tube (i.e. a cheap fuse), in the power loop would be detrimental to the performance of the components.

I decided to revamp my DIY power supply I'd built for the Cambridge Audio 640p phono stage and DACmagic in order to test this out - and since it's a DIY project there is no UL Certification to void.

First, I bypassed the fuse link completely to confirm there would be an improvement and give me the best benchmark to compare against - YEP - BIG DIFFERENCE - much more this, that and the other :-)

So then I started looking for hi-fi fuses - WOW!!! - talk about pricey.

Two fuses for the power supply was going to cost $120+ AND I thought I'd probably have to buy a better quality fuse block to make the most of those fuses.

Then a moment of enlightenment - most power supplies and conditioners are protected by pushbutton breakers and not fuses.

I found breakers of the required current rating and installed them into the power supply. I imediately noticed that there was no deteriation in fidelity when compared to the same unit with the fuse link bypassed - GREAT!.

On reflection, the fuses I had in place were rated at 3 amps - so they use a pretty thin fuse wire in them. If I had used a fuse of a higher rating, i.e. it uses a thicker conductor, then I believe that there would be less of a difference between the fused and bypassed implementations

SO - do the expensive fuses work?

Well the empirical evidence out there would suggest they do
- I do know the cheap fuses are not good!

I know bypassing them does improve the sound - a lot in my case
- BUT THAT'S NOT SAFE FOR ONGOING USE

I know breakers work as good as bypassing the fuse
- BUT MESSING WITH A POWER SUPPLY VOIDS UL CERTIFICATION - NOT GOOD!
- FYI a couple of licensed technicians I know WILL NOT change the design of a power supply at all.

I believe the amount of benefit is related to the fuse rating
- but don't go replacing 3 amp fuses with a 20 amp fuse - that's not safe either.

Whilst looking for fuses I discovered AMR Gold fuses priced at $20/fuse.

Now that's definately more affordable than most others at 3-4 times their price.

One supplier I know of in the US is Avatar Aacoustics

If you have had experience with quality fuses please share - especially if they are "modestly priced" i.e. $20-$30 per fuse. And please provide a source :-)

Also, can anypne confirm that Slow blow fuses are better than regular?

And Remember - IF YOU AIN'T LICENCED - GET A TECHNICIAN!

Many Thanks
williewonka

Showing 5 responses by pack

No offense boys, but do you really think that if the quality of a fuse was a factor in the sound and performance of a high end amp that the designer of that amp would have addressed it ? Did I hear ....BONEHEADS!!..............
You don't seem to get the point, When Nelson Pass designs an amp, every consideration is taken into account in the circuit layout. Ya they cost some bucks,but check out the rail fuses. Pass would laugh at your mumbo jumbo as I do, you tweak guys should pay more attention to physics than some sales "pro". There seems to be no end to the lunacy out there .
OK, I guess you guys think with your audio hearts and thats OK,after all if one thinks its true then in his ears it may be so. But if you do a square wave sweep thur a circuit with its well thought out fuse you will see no difference at all. I stand by my statement that its all in your head, please take no offense, I think your passion is why we love the Audio arts and this love drives the engine of progress.
This has turned into a lively conversation, everybody is thinking. Here is an suggestion regarding sound : If you isolate your power amp ,your pre-amp and your CD player with electromagnetic shielding ( find it on the web , its cheap! ) If you do this ,you will be amazed, nothing short of total sonic improvement will be had...........pure science boys !
Geof, Did you know that the thickness of your skull has an impact on how you perceive sound ? I don't mean this as a joke,its true. You should have more faith in electrical science , it has brought what might be considered miracles into our lives. But you know being human and a little bit different from each other , when it comes to the things that effect our senses such as musical reproduction , we should allow the choice of a device that sounds the best to us. Look at all the pre-amps,amps,digital gear,etc. we have to choose from . These devices are "Tuned" by there perspective designer based on his idea of what music should sound like. Case in point, the biasing of an amplifier. But getting back to science for a second..............physics does dictate certain truths......these truths have everything to do with the functional ability of a given devise to do what it is supposed to do. That is to say a well produced square wave thru a circuit once achieved is the best electrical possibility. Perhaps if we took a good decongestant an hour before our listening session, there would seem to be more clarity in the high end area ?