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

Yuviarora, found you over here on this thread.  I am in the planning stage of a crossover upgrade (sorry to be off-topic from fuses; mine are all Synergistic Orange).  My largest cap is 220 uF and next largest is 13 uF.  You sound very pleased with a .01 uF value bypassing a 115.8 uF cap, correct?  You mentioned having initially tried them in the wrong position, which I didn’t follow.  When you tried a higher value bypass cap, was it in the ideal position?  As I understand it, a good value bypass cap for a 115.8 uF cap is in the 1% range or 1 uF.  I have several .01 uF Duelund silver foil caps, but hesitate to try them with much larger value caps until hearing the experience you described.

 

 

@gererick the 115.8uf capacitors are parallel capacitors installed as (3x)33uf+(1)10uf+(1)6.8uf Mundorf Supreme evo oils, all adding up to 115.8uf.

I first installed the .01uf foils at the furthest point away from signal output, and they completely muddled up the sound, they just sounded bad.

After taking them out I reinstalled them on a whim, but this time around I moved them to the front position, so they were in the closest position to the signal output, and my audio image just instantly snapped into focus.

It was like going from 1080p to 4k. (I am still going through burn-in, and they haven’t settled in completely as of yet).

I don’t know how a value as small as .01uf can have such a difference in my application, but it did, and they are staying in for good.

 

If you have the bypass capacitors on hand, try them out, you can find out for yourself if they work for you. They are pretty easy to take back out if you do not like what you are hearing.

I am bypassing both my tweeter caps 10uf, and mids 115.8ufs.

Also to add:

I can’t tell you if 1uf would be a better value to use in my case either, I haven’t tried a capacitor that big, but I am sure others can guide you in that regard.

 

I wonder if anyone has bypassed the bypass? :) Tinned Copper and Silver foil together?

Yuviarora, thanks for your reply.  If I understand the drawing correctly, my positive comes in from the amp, goes through an inductor, then heads toward the drivers. On its way to the drivers, there is a junction where a wire goes from the positive to the negative.  On its way to the negative, there is a resistor and then a capacitor and then the negative wire.  In that instance, what is closest and furthest from the signal output?  (Sorry for my layman’s description)

Sounds like it is a single capacitor? If it is, you can just bypass it normally. Make sure that on the bypass capacitor the outer lead is connected to the side between the resistor and the capacitor. (Duelund bypass capacitors have directionality)

From Duelund "The outer lead out, closest to the edge of the capacitor, is connected to the outer foil and as such should be connected to the lowest impedance path to ground, generally the signal output."

 

 

Your signal is going out towards the driver, So Negative, to capacitor, to resistor.---> That is the direction of the signal, output is from capacitor to resistor, input is negative to capacitor.

Hope that makes sense.

 

 

Thanks!  Yes, it is currently a single capacitor but I may end up using multiple caps to get to 220 uF (like you did to get to 115.8 uF).

@gererick I would go that route for sure. Good quality caps installed in a parallel configuration would work very well  👍