2. misc-audio
  3. 169932-104649

Fuses

I’ve read of views on whether amp fuses impart any sound quality or coloring. I had a recent experience that has made me re-think my views (fuses do not affect sound) and wondered if others had a similar experience. 
I have a Line Magnetic integrated amp. After heavy regular use for over 5 years, one day it just wouldn’t power up. After checking the power supply, I assumed it must be a blown fuse. I recalled that Line Magnetic sent with the amp two replacement fuses of the same type/quality that was pre-installed. I dug out one of them from storage, replaced the fuse and the amp powered up normally. 

What surprised and delighted me was the change in sound with the replacement fuse. Fuller bass, more detail and more warmth. I have rolled the tubes several times in the amp, and am attuned to the subtle changes that can make. Popping in a fresh fuse seems to have had a similar affect. And these appear to be cheap fuses, available for a few dollars at most. I don’t think I understand any of this. 
bmcbrad
noske
783 posts
 
OK, thankyou, I'm glad that its clarified that you are very experienced.  I think that is important.

The ceramic build having heat trap protection, that's interesting.  Is this good?  My lay intuition suggests that it might be good if any heat was dissipated.  Obviously not.

Anyway, on the ACME site they say that ceramic may be inappropriate for amps that do not have inrush protection, or the fuse may be "destroyed".   How do you know if an amp (solid state) has inrush protection?  ACME suggest using a stock (Littelfuse?  they don't say) ceramic fuse first and just wait and see....if it is destroyed?

https://www.revolutionpower.com/acme-audio-labs-large-silver-ceramic-fuse-cryogenic-treated

I am not going to pretend that this strikes me as particularly robust advice coming from a manufacturer of premium fuses for use in quite expensive equipment..
yuviarora's avatar
yuviarora
537 posts
 
@noske  Most Solid state amps have inrush protection, it is tube amps that you have to usually worry about, and that is why people use slowblow fuses for them.
If a ceramic fuse blows on your solid state amp, it  won't damage the amplifier, you  would just have to go a size up and test it out to get to the required functional rating. 

noske
783 posts
 
@yuviarora

Thanks, OK, that's good to know, very good and comforting general advice.  (anecdote - my SS amp manual is inconsistent anyway  - on one page it says 1.5A, on another page 2A.  I use 2A.)

Yes, I had kinda guessed that about amps with glass, as my tube amp has the slowblow fuse as part of the IEC socket enclosure before any possibility of it being able to be manipulated by anything.




fiesta75
1,378 posts
 
My vote goes to George for electronics. MC makes some simple mistakes like series and parallel resistors... The best fuse is no fuse, agreed. Instantaneous CB unless your trying to protect your multimeter...
yuviarora's avatar
yuviarora
537 posts
 
Okay.....soooo I am in the camp of not bypassing signal capacitors. At least in my application, they caused issues in both positions.
Sound got smeared in the mids, and the timbre change in the tweeter position came with a similar smudging of sound. The bypass capacitors really affected transparency in my system, and affected depth of stage.
I only had them in for 3 or so hours, but I didn’t enjoy any part of this installation and have taken them back out.
@georgehifi you were right, at least as it happens to be the case in my application.
I am now in the camp for installing the single best possible quality cap that you can use in the signal path.

Now having said that, I had voltage imbalances in my tweeter position, 1200v vs 600v (big cap vs bypass)
and mids 115.8uf capacitors bypassed with a .01uf foil capacitor.
Neither position sounded good.

More to discover