Synergistic Research Quantum SR20 fuses

gordon said Pardon my "Electro-ignorosa" but since the incoming power is A/C and the same to the speakers, then no matter which way a fuse or cable is used, is it not considered to be in one direction only 50% of the time?
Playing the devil's advocate: if the wave form were perfectly symmetrical and the current draw perfectly synchronized then it wouldn't matter. If there are any non-linearities in the fuse a non-symmetrical wave forms could have non-symmetrical effects. Also fuses by definition have non-linear effects on the current, so their effect definitely depends on the device they are used in: whether that effect is significant is another question.
gordon said Pardon my "Electro-ignorosa" but since the incoming power is A/C and the same to the speakers, then no matter which way a fuse or cable is used, is it not considered to be in one direction only 50% of the time?
A pure and perfect sine wave flows in one direction only 50% of the time. A musical wave form will be more or less than 50%, but over time probably averages 50% positive and 50% negative.

Ideally, the incoming power AC and the AC to the speakers have nothing to do with each other. A perfect power supply produces clean DC which is then modulated by the musical signal which powers the speakers. That is we are always listening to the power supply, modulated by the music.

(As an aside, the positive aspect of each musical waveform almost always is is not a mirror image of the negative going part, regardless of sampling rate. Weird, huh?))

The fact that AC from the wall (or PowerPlant) goes in both directions and is essentially a sine wave - with the positive going and negative going mirror images of each other - makes directional fuses highly suspect in concept.

To work well, incoming power must be as symmetrical and as perfect a sine wave as possible (hence the benefits of a PowerPlant). We do not want our incoming power modulated by a fuse or any other component prior to rectification.

My skeptical self asserts that if a non-symmetrical incoming power fuse makes a component sound better, there is something wrong with that component’s power supply. The job of power supply is to remove any such abnormalities in the incoming power and produce pure DC.

Am I the only one having this problem?

Although I thought the SR fuses sound great, the slow blow version of the fuse, in my system, has been unusable.

I have SR fuses in my power amps, and in my isolation transformers. They are fast blow 12.5A and 15A fuses, and have performed flawlessly.

When I have tried to use SR slow blow fuses, all of the fuses have popped on device turn on. The devices in question? The Bryston BDP-2, and the Cary SLP05. In the case of the Bryston, even a larger value fuse (a 650mA versus the specified 500mA) popped on turn on – fast blow fuse behavior.

Has anyone bought SR slow blow fuses lately and had this problem?

I’m thinking the fuses are mislabeled?

Yes, I had the same problem with the SR fuses with my Bryston BDA-2.

The Cable company confirmed that the SR Fuses cannot handle some of the initial surge that the Bryston requires on turn on. They actually suggested using the next higher value when using it with the Bryston BDA-2.

Man, After reading the posts on this thread I am confused as to which way the SR fuses should face.

So, went ahead and reversed my SR fuses. I have them now situated so that the SR is now near the back of the Dac (IEC end).

The 20 on the fuse now faces the front of the unit.

I do think it is a little better in sound quality this way.

ozzymilton said Yes, I had the same problem with the SR fuses with my Bryston BDA-2.

The Cable company confirmed that the SR Fuses cannot handle some of the initial surge that the Bryston requires on turn on. They actually suggested using the next higher value when using it with the Bryston BDA-2.


Even the next value up popped in the BDP-2. In the Cary, I switched back to HiFi Tuning fuses, which work with no problem. I’m not comfortable using a higher value SR fuse (not that it would make any difference based on my Bryston experience) in tube equipment.

I’m of the opinion that SR is selling fast blow fuses as slow blow (when I asked for the break spec on the fuses, they did not reply – big hint)

So, I’ll be doing HiFi Tuning for slow, and SR for fast.

oddeophile said David,

I believe that is correct. the “20” should be at the cap end and the “SR” end inserted into the fuse holder.

Odd

I’m not sure which end has the 20 on SR fuses, but I use our Synergy HiFi fuses, which are directional, on our P10 and there’s no question in my mind that the arrow should point toward the back. I assumed the arrow should point inward when I installed the fuse, but after a few weeks of break-in it didn’t sound right until I switched the fuse.

I will agree with an earlier post that HiFi Tuning have a harsh, aggressive quality; sharp and piercing in my experience.

Can someone confirm the details about DirectStream fuse replacement? Only one person has guessed at the value/type on this post, with no validation, a few suggestions about the direction and no info about how to get to the fuses. Someone who knows what they’re doing, please comment on these items. Is this correct:

  • 1A, mini, slow-blow fuses,
  • Direction: current flowing from front to back (arrow pointing to the back) on both fuses,
  • Also, how to get at the fuses, just remove the two screws near the upper back edge?

Hi, Jaguar

You need two 5x20mm 250V 1 amp slow blow fuses

One gets to the fuses by taking the top cover off. There are videos on-line addressing how to do so, as does the kit instructions for the DS.

Directionality: AC flows equally in both directions - ideally in a symmetrical sinewave - from positive to negative. If you think an AC fuse can possibly be directional despite this tidbit of physics I suggest trying both directions and determining if you can reliably hear a difference.

Happy fuse swapping!

How to open the DS to access fuses.

The screws ARE directional.

http://www.youtube.com/watch?v=wR_PFNuyc_k

What a support team!

Elk said Hi, Jaguar

You need two 5x20mm 250V 1 amp slow blow fuses

One gets to the fuses by taking the top cover off. There are videos on-line addressing how to do so, as does the kit instructions for the DS.

Directionality: AC flows equally in both directions - ideally in a symmetrical sinewave - from positive to negative. If you think an AC fuse can possibly be directional despite this tidbit of physics I suggest trying both directions and determining if you can reliably hear a difference.

Happy fuse swapping!


Thank you Elk. I was hoping for 1A since I already have those on hand. Yes, I’m completely on board with directionality. I felt much better coherence when switching the fuse in the P10, though I didn’t do a double blind test. I don’t understand the physics of anything, but my Chinese friend who developed the Synergy fuses has a PhD in some sort of astro-physics thing and told me they’re directional because of the orientation of the metal crystals.

Fascinating.

might he be willing to post an understandable explanation for those of us who may be bewildered by the concept?

gordon said How to open the DS to access fuses.

The screws ARE directional.

http://www.youtube.com/watch?v=wR_PFNuyc_k

What a support team!


The video is obviously good but most non kit owners will not be able to do it until they get the 4 screws required.

#4-40 X 1-1/2" “all thread” screw rod

They are not included with non kit Direct Streams and not easy to find locally.

jaguar said

I felt much better coherence when switching the fuse in the P10, though I didn’t do a double blind test.

This is all it takes. If it sounds better to you - whether there actually is a difference or note - it is better. Besides ,it is free to play with the direction the fuses go in. It is a hobby; it is designed to waste time. :)

To get the top off:

Tilt the unit up vertically on its side, with the AC input power connector nearest the table.

Use a a small screwdriver, pin guide, whatever, push the lid off using the four holes where the cover screws were. You can also buy long screws of the same size, thread them in a bit, and use them to push the lid off, and then remove the screws.

Anyway, once the lid is pushed part of the way out you can grab it and pull it out the rest off the way. Push the sides equally so the top does not get wedged on the way out.

It is harder to describe than to accomplish.

Just an interesting comparison.

http://singaporehifi.blogspot.co.il/2014/01/aftermarket-fuses-synergistic-research.html

But what does his wife/girlfriend - who does not care about audio and was in the other room - think?

jaguar said
Elk said Hi, Jaguar

You need two 5x20mm 250V 1 amp slow blow fuses

One gets to the fuses by taking the top cover off. There are videos on-line addressing how to do so, as does the kit instructions for the DS.

Directionality: AC flows equally in both directions - ideally in a symmetrical sinewave - from positive to negative. If you think an AC fuse can possibly be directional despite this tidbit of physics I suggest trying both directions and determining if you can reliably hear a difference.

Happy fuse swapping!

Thank you Elk. I was hoping for 1A since I already have those on hand. Yes, I’m completely on board with directionality. I felt much better coherence when switching the fuse in the P10, though I didn’t do a double blind test. I don’t understand the physics of anything, but my Chinese friend who developed the Synergy fuses has a PhD in some sort of astro-physics thing and told me they’re directional because of the orientation of the metal crystals.


Based on this, I’ve unsoldered and reversed the direction of every resistor on my PWD circuit boards…amazing improvements in imaging, soundstage, timbre and “PRAT” …highly recommended!!!

One would think manufacturers would learn to get the directionality right when they make stuff. It is always up to the liberal arts degreed end-user to get the engineering right.

Have you tried turning all of your components around so that they face the wall? It matters.

I know, right?

My tube components work best upside down to warm the components on the circuit board so electrons flow in a more fluid, organic, musical manner.

Where do you think the Engineers get their “inspirations” from?

“An education rooted in the liberal arts not only makes individuals productive global citizens, but it also leads to increased lifetime earnings. The world needs and has always needed individuals who have a firm foundation in critical- thinking skills.”

“A liberal arts education develops leaders who can overcome challenges, adapt to the changing world, and weather economic shifts to achieve career success over decades."