Synergistic Red Fuse ...

It's possible that SR fuse is affected by the turn-on sequence.  My Pass XP-15 phono stage has no on/off switch.  It's powered on once the AC cable is connected.  I blew two Red fuses before I successfully used a Red with higher amperage rating.

By comparison, my PS Audio BHK amp is less likely to blow a fuse because it uses a lengthy turn-on sequence.  I'll know for sure when my Black fuses arrive.

I also agree that some fuses are directional.  I tried an Hi Fi gold fuse in my BHK Preamp.  In a single blind test, my wife (who's a musician with better hearing) agreed that one direction was pretty good, while the other was quite harsh (almost unlistenable).  This is a surprising because I never thought that it would be so obvious.  We'll try the same test with the Black after the burn-in.  

"It's possible that SR fuse is affected by the turn-on sequence.  My Pass XP-15 phono stage has no on/off switch.  It's powered on once the AC cable is connected.  I blew two Red fuses before I successfully used a Red with higher amperage rating."

Exactly the same as my Ayre K-1xe phonolinepreamp/power supply where I lost two 1A Black fuses before going to a 2A.

Best to you mtseymour,
Dave

mtseymour,

Have you replaced all the fuses in your BHK amp with the black fuses?  How much better is your BHK after replacing the 4 rail fuses compare to the 2 main ones?  thx.

Allan

Thank you for your inputs about the value and margin in black fuses.  I am now experimenting with the direction of these fuses. 

I have been told that SR fuses should be oriented such that the writing on the fuse is in the direction of signal flow (ie looking at the SR label on the fuse, arrow going from S side to R side of the fuse). 

For fuses on AC power line, I am assuming that AC "signal" flows into the equipment thru Live/Line/Hot terminal and out thru the Neutral terminal.

Thus, for fuses on the Live terminal of the input IEC power connector, the S side of the SR marking on the fuse should be towards the Line terminal of the IEC connector.  

For fuses on the Neutral terminal, the R side of the SR marking is towards the Neutral terminal of the IEC Neutral connector. 

Please let me know your comments and if this theory is a proper way to orient fuses.

Alex

For fuses on AC power line, I am assuming that AC "signal" flows into the equipment thru Live/Line/Hot terminal and out thru the Neutral terminal....

... Please let me know your comments and if this theory is a proper way to orient fuses.

Hi Alex,

While energy is of course transferred in the direction from the outlet to the component, the AC hot and AC neutral conductors are involved in that process equally. And the AC current alternates direction in both of those conductors (and also in the fuse), every 8.333 milliseconds for 60 Hz AC, and every 10 milliseconds for 50 Hz AC.

Beyond that, all I can say in response to your question is to suggest that you read my post in this thread dated 10-28-2016, which appears near the middle of the previous page. And note that if the comment by Atmasphere that I quoted in the thread is correct (and he has indicated that he has verified his contention experimentally) it would follow that the existence of sonic differences resulting from changing the direction of a fuse does not establish that fuses are inherently directional.

IMO. (And also, as you’ll see in the comments quoted in the post I referred to, in the opinions of four different experienced designers of well regarded audio electronics). Opinions of other audiophiles, most of whom are not electronics designers, will certainly differ in many cases.

Good luck. Regards,
-- Al