Any comments on different fuse types and how they affect the sound of a supply? Glass vs ceramic and or sand filled. Is this strictly an issue of microphonics? Is there such a thing as a low impedance fuse? What are the mechanics behind fuses impacting the sound of a supply. Are there recommended types of fuses for audio or ultra low noise measurement equipment? Not referring to cryo treated fuses here but fuse style types. Thanks best regards Moray James.
James,
You may check this thread: http://www.diyaudio.com/forums/showthread.php?s=&postid=180927&highlight=#post180927
Those were the times when more serious people were frequenting this forum.
You may check this thread: http://www.diyaudio.com/forums/showthread.php?s=&postid=180927&highlight=#post180927
Those were the times when more serious people were frequenting this forum.
As usual, I agree with Peter. (for what it worths )
Why everybody laugh when something heterodox is investigated?
This is an empyrical hobby. You can't predict everything based on known (or supposedly known) facts.
I've heard that Yves Bernard André (YBA) uses gold plated/ OFC copper fuses, and this man seem to know about sound
Personally I believe everything has a sound. Some parts may have little influence but others may have a big one. It's about experimenting.
It can be very tiring posting on "resistor's sound", "cap's sound" or "wire's sound" threads.
Regards
Mauricio
(for what it worths )Why everybody laugh when something heterodox is investigated?
This is an empyrical hobby. You can't predict everything based on known (or supposedly known) facts.
I've heard that Yves Bernard André (YBA) uses gold plated/ OFC copper fuses, and this man seem to know about sound
Personally I believe everything has a sound. Some parts may have little influence but others may have a big one. It's about experimenting.
It can be very tiring posting on "resistor's sound", "cap's sound" or "wire's sound" threads.
Regards
Mauricio
Fuses are not transparent. Even Randy Slone claims that fuses cause distorsion, so they most likely do, although he probably only advises against using them in the signal path. The primary effect is most likely thermal. A fuse is supposed to melt at a certain current. That means it must get warm already at much lower current, so we are likely to have quite a non-linear behaviour. Compare, for instance, with resistors, that also distort due to thermal effects. The fuse is likely to get much hotter and thus suffer much more from such non-linearities. On the other hand, it is already a very low resistance from the start, so its effect is limited for that reason. Perhaps there are other kinds of thermal effects too?
Until any of you can pass an A-B-X type of test with fuses I'm not buying this nonsense. If a fuse worries you about sound quality then you better not think about the other weak points in the signal path. Lead solder, microscopic wires leading to the chip die, steel wire used in tube pins, aluminum foil in capacitors, etc etc. A fuse is going to be what, a few ohms at most for a very low current. The thermal effect is going to be unmeasurable without using a bridge. Whats 0.05 ohms going to do?
AHP makes audio-grade fuses with copper filaments, a resonance-optimized ceramic housing, dampener filling, and gold-plated contact area. These are a very popular tuning accessory in Germany right now, and accepted without much scepticism about their possible benefits, even at Eu9-7 a piece.
What surprised me is the effect they had on one piece of equipment with an ordinary tray-style fuse holder built into the IEC inlet, since I didn't think that without a matching audio-grade holder, these fuses would have much effect. But they did.
On other equipment, I went through the trouble of making a few fuse holders to experiment with. My experiments revealed the importance of contact surface area, material, plating, contact pressure, wire termination mechanics, attachment of fuse holder to chassis, with best results achieved with high contact pressure, copper-plated brass, cylindrical fuse holder with crimp fitting for wiring, and teflon outer dialectric.
Somebody once mentioned that perhaps Furutech or some other company should manufacture an audio-grade fuse holder one day, since the existing options for these are really unimpressive from anything else but a safety perspective. Does anyone know of any audio-grade fuse holder for 5 x 20m fuses?
What surprised me is the effect they had on one piece of equipment with an ordinary tray-style fuse holder built into the IEC inlet, since I didn't think that without a matching audio-grade holder, these fuses would have much effect. But they did.
On other equipment, I went through the trouble of making a few fuse holders to experiment with. My experiments revealed the importance of contact surface area, material, plating, contact pressure, wire termination mechanics, attachment of fuse holder to chassis, with best results achieved with high contact pressure, copper-plated brass, cylindrical fuse holder with crimp fitting for wiring, and teflon outer dialectric.
Somebody once mentioned that perhaps Furutech or some other company should manufacture an audio-grade fuse holder one day, since the existing options for these are really unimpressive from anything else but a safety perspective. Does anyone know of any audio-grade fuse holder for 5 x 20m fuses?
D. Self had some measurements on fuse at power amp output. Caused mostly LF distortion.richwalters said:
Not so big supprise if its causing measurable deteriation on performance at power amp output. Power rails or even mains fuses are more on the side of woodoo-land. (assuming that amp has reasonable PSRR)
mzzj said:
D.Self quoted in a paper "low noise amps and granularity distortion AES 1987"<< No passive contact on the verge of falling apart contributes to distortion>>..........That article was written in the days of MC phono cartridges.
If the experts can't sort this out then ......oit doesn't matter how frail my soldering is..........I think in all honesty........there are so many reed relays with contact resistance used in consoles that the contribution of a fuse in the audio chain is the law of diminishing returns. The passive aspect is open to intrepretation, unless fuse is soldered in circuit.
richj
Fuses work by melting when they get hot. The power that causes the heating is I squared R, so resistors must have resistance in order to work. I just measured a few 20mm fuses that I had with a Fluke 8012A;-
T10A.......0.013 Ohms
F5A.........0.021
T1.6A......0.053
T1.0A......0.139
F500mA..0.183
F200mA..6.94
A 100mA fuse had a resistance greater than 20 ohms.
This resistance is not linear, and increases with current as the fuse heats up. Measurable distortion occurs if it's in series with a loudspeaker, reported by all those who have measured it. I once included the fuse within the feedback loop of the amplifier to reduce this effect; a 1k resistor in parallel with the fuse maintains dc stability for the amp if the fuse blows, while reducing fault current to negligible levels.
Apart from this, I'm sure a fuse sounds better than a blown speaker, should the unthinkable happen.
T10A.......0.013 Ohms
F5A.........0.021
T1.6A......0.053
T1.0A......0.139
F500mA..0.183
F200mA..6.94
A 100mA fuse had a resistance greater than 20 ohms.
This resistance is not linear, and increases with current as the fuse heats up. Measurable distortion occurs if it's in series with a loudspeaker, reported by all those who have measured it. I once included the fuse within the feedback loop of the amplifier to reduce this effect; a 1k resistor in parallel with the fuse maintains dc stability for the amp if the fuse blows, while reducing fault current to negligible levels.
Apart from this, I'm sure a fuse sounds better than a blown speaker, should the unthinkable happen.
I have no idea whether the fuses (in the supply rails) have any effect on the sonics of the amp, but in my experience they can themselves generate sound!!
When testing my amp into 8 Ohm dummy loads (at high power levels) with RMAA I noticed I could actually hear the RMAA test tones even though there were no drivers connected. It took me a while to find what was emitting the noise (I could hear it from a couple of meters away!!!) but it turned out to be the fuses. On carfefull examination I could actually see the wires inside vibrating back and forth (well actually it was more of a case I could see a blur where the wire normally was ....
Tony.
When testing my amp into 8 Ohm dummy loads (at high power levels) with RMAA I noticed I could actually hear the RMAA test tones even though there were no drivers connected. It took me a while to find what was emitting the noise (I could hear it from a couple of meters away!!!) but it turned out to be the fuses. On carfefull examination I could actually see the wires inside vibrating back and forth (well actually it was more of a case I could see a blur where the wire normally was
.... Tony.
One thing is for sure: My power amp has a fuse with bad contact. This is bad for the sound, regardless of fuse type 
This fuse makes my output relays to go and off. When the relay is off it's silent, the speakers that is. Bad for the sound.
My best advise is to use good quality fuse holders and maybe after some years pay the fuses some attention.
This fuse makes my output relays to go and off. When the relay is off it's silent, the speakers that is. Bad for the sound.My best advise is to use good quality fuse holders and maybe after some years pay the fuses some attention.
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