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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
mapman's avatar
mapman
22,200 posts
 
I'd trust Nelson Pass to know the right fuse to use in his products.

Not to say changing a fuse might not sound different for many reasons case by case but predicting how in advance is a pot shot.

Plus, ehenever one mucks with the internals of a complex device there is some risk, but if fuse replacement is done correctly and with a reliable product, there should be no problem. If. And if not product warranties are voided in the process.

Most everything one buys these days is easily returnable/refundable. Companies with poor customer service/customer satisfaction policies do not survive long.

As long as the fuse is what is says electronically and works accordingly, no real risk then if good customer service is in place.

WHat if something unexpected happens to the device as a result of changing the fuse? Shit can and does happen. Each knows best how qualified they are to attempt whatever it is they might attempt and deal with things as needed if something should go wrong unexpectedly.

Just being real. Everyone can judge for themselves best what to do or not.
charles1dad's avatar
charles1dad
10,250 posts
 
Well said Mapman,
We all make our choices as we see fit. I just don't need someone telling me or others what will or won't work when we've actually done the listening and report our individual outcomes. That is the ultimate test, otherwise it's only conjecture.
Charles,
mapman's avatar
mapman
22,200 posts
 
Just remember, the mere action of removing and re-inserting a fuse alone COULD make a difference, if the new electric contacts are better/cleaner as a result of the process.

That aside, if one fuse sounds better/different than another in repeated test cases, that's hard to refute.

No way to know for sure beforehand. YMMV.
lacee
811 posts
 
I would say that a cheap fuse,with it's paper thin glass envelope may be more prone to disaster after repeatedly removing it.
I don't think it wise to infer that this practise is just as good as trying a new fuse.
You know how some feeble minds can be swayed when they read about such practises.

If you like stock fuses and aren't interested in trying an upgrade leave well enough alone.

I would note that in 30 years of running DIY fuses or bypassing them altogether I ner once had a meltdown or accident.

I am not endorsing this practise,just as I wouldn't endorse removing and reinserting stock fuses to try and get an improvement in sound.

What I can state is that in every instance,the sound with the stock fuse was inferior to what I replaced it with, in more than one component and over 3 decades.

I have been using upgraded fuses for the past 4 or 5 years and have not had any problems in any of the components(cd ,amps, pre)that I've used them in.

I can also state that when one does do something stupid like not pay close attention to the small fuse values, a HiFI Supreme fuse will blow, so yes they do what they are supposed to do, and that is self destruct before something else does.
schubert
7,386 posts
 
Most of what is relevant, in audio as in life, is unmeasurable.
Doing Newton in a Quantam world .
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