Fuse Direction for Pass Labs Amp and Preamp

@mitchb : I see you have drunk the fuser Kool Aid! How can you believe this nonsense that a small piece of wire - which does not carry a music signal - can somehow change the character of a component - and cost hundreds! Enlighten me!

Jason
How you feel about fuses now people felt about power cables 25 years ago. People in fact do hear a significant difference between stock fuses and high end fuses. Why a little wire makes such a dramatic difference I don’t know but it does. It has been proven by people’s experience. There are those who feel power products like cables and connectors don’t make a difference but they do. Not always positive I admit as everything is system dependent.

I can tell you that Lloyd Walker suggested that I try the fuse both ways in my Walker Motor Drive to see which direction I preferred.  He could hear a difference, but I could not.  I'd suggest that you follow Lloyd's advice and see if you have a preference..

My situation is that I am doing 4 components at the same time. Technically I should do one at a time and swap the fuse to hear which works best but I was hoping to just install the 4 fuses at the same time. Someone sent me a diagram in a different forum which shows which way the direction of the fuse should go. I will follow the diagram sent to me as a guide.

I am thinking that the direction should be the lettering left to right with the beginning of the lettering facing out of the amp and the end of the lettering facing into the amp. Does this sound right?

@mitchb 

Not unless the fuses are in a DC circuit, and somehow have better conductivity in one direction rather than the other!

What people hear when they swap fuse direction isn't the fuse having 'directional' properties! Its a combination of the fit of the fuse in its holder (resulting in a lower voltage drop across the fuseholder) and expectation bias. The former is measurable (and slight), the latter is not.

It is impossible for a fuse to have a directional property in an AC circuit! That would cause it to favor one half of the AC power waveform and not the other- this would cause the fuse to heat up, since in the non-favored direction its resistance would be higher. Ohm's Law dictates this.

This would cause the fuse to heat up and fail, possibly within seconds of operation.

This statement is false:

Why a little wire makes such a dramatic difference I don’t know but it does. It has been proven by people’s experience. There are those who feel power products like cables and connectors don’t make a difference but they do. Not always positive I admit as everything is system dependent.

You can measure voltage drops across power cords and that can affect power amps that draw a lot of current (IOW they obey Ohm's Law). But its quite incorrect to say that this aspect of fuses is 'proven'. Its clearly not; I explained why. Further, I presented the explanation of why its actually impossible.

There are a lot of myths in audio, for example the idea that a certain speaker or amplifier can sound favor a certain genre of music. These myths exist in a viral form and infect in a way not unlike actual viruses. Once you disabuse yourself of them, you'll find that you can make greater progress on the sound of your system.

@atmasphere,

+1 Well said 😎

This is living proof of zombie threads coming back to life. Just try it both ways as there are no shortcuts and if and when you hear a difference, go with the way that sounds best to you.

All the best,
Nonoise

the idea that a certain speaker or amplifier can sound favor a certain genre of music.

You never owned Bose 901s or have read why Amar Bose designed them that way, I'm guessing.

Dear @mitchb : SR owner is a marketing " genius ". I own SR and other bs high-end fuses.

" People in fact do hear a significant difference between stock fuses and high end fuses. "

Of course we " hear " that differences because we already spend a lot of money and we " want " to " hear differences " where it can’t be differences at all.

Don’t spend your money but invest with for something that really can improve the quality room/system performance levels as room treatment.

 

Anyway, do what you think is the best for you.

 

" I redid the crossovers with high end parts "

 

that’s exactly as the SR fuses because does not exist " crossover high end parts ", only bs really inferior expensive parts for we audiophiles eager to go with. We customers are the " bu$ine$$ " in the audio world, especially for after market tweaks items.

 

 

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

You never owned Bose 901s or have read why Amar Bose designed them that way, I'm guessing.

@russ69 This is such a great example of what I'm talking about (the myth bit)!

I'll put it to you this way: If someone comes up with a way to get home stereo electronics to favor a certain genre of music, they will be a millionaire overnight. There really isn't any way to do it (if you feel I'm incorrect about this, by all means, please get out there and show the rest of us your circuit or speaker design!!). What makes a speaker (or amp, cartridge, cable, etc.) good for one genre makes it good for another since we humans uses the same range of frequencies for music regardless of what the nature of the music.

Bose designed the 901 to mimic the concert hall, which might suggest to some that its better at classical music. It isn't. I regard it as a failure (insofar as accurate musical reproduction in the home is concerned; if meant to make money it seemed to be successful at that); at the very least there should have been more directly radiated information. The understanding of how the ear processes late delayed information was less understood back in the 1960s (if delayed about 10mS or more, the ear can use the rear-firing information for echo location, thus making the center fill more palpable; to do that the rear of the speaker needs to be at least 5 feet from the wall of the speaker behind it) when the speaker was designed.

 

Have fun! 🙃

Lets not forget the biggest myth of all East coast, West coast, sound. LOL 😎

 

Mike

I’m really surprised to read atmasphere say that a fuse can’t have a preferred direction. That is also telling me you don’t look at the wire and how it’s pushed through the dies before soldering them in a preferred direction. Is that right? You don't care which direction the wire is soldered in? I do! 

Second if a Rectifier tube can have such a great affect on a valve amp, what makes people think a fuse, power cable, wall outlet won’t. Not only is there a difference in the sound, there is a reason why. The properties of two different end caps and the way the thermal filament is constructed along with how it was pushed through the dies. AND there is no direction?

Oh YES there is.

It’s simple AC moves in a direction towards the source, period. When it gets there it produces heat if it’s used and it’s moving in that direction because it is being used. The chicken or the egg. Heat is the result of use.. It’s certainly not hot to the tough at the receptacle is it? NO it’s hot where it’s working or producing heat.

You build amps I build cables and equipment. We even have direction on our inline DC fuses.. AC on the outside, DC on the inside.. That’s what is preached by most mechanics.

No direction? WOW! I thought that was figured out 30 years ago, from the 1800 old tech teaching. Things change. I’m actually reading the EE 2020 addition updates, Nano arcing and the quantum effects, Chip mortality # 1 killer, nano arcing and how alloy treatment prevents it. No bare hands anymore. The acid in your hand causes issues in the solder. Hand acids can actually etch a bearing face and cause a failure.

Most of the kooky, loopy stuff audiophile have been saying for 30 years is published reading for Electrical Engineers NOW to keep up.

I rewired two sets of Cary MB. Great result. I’ve seen 30-35 amps redone in our little group. Brian Cheney from VMPS was one. James B, did the work before they both passed in 2012. Cool tea for me.. I'm off work..

BTW another mechanic loaned me the book, we're both into stereo equipment. He's almost 70. Western Electric nutter. AC/DC speakers.

@atmasphere +1

Thank you for speaking truth to these myths that continue to be perpetuated by companies like Synergistic Research.  I don't know how people that own companies like that sleep at night.  Ted Denney and the My Pillow Guy are one in the same.

Once you're done buying your fuse, I have a bridge to sell you? You can only drive in the direction of the letters on the bridge.

It’s not a question of truth, it’s a question of weather you keep up with what the heck is really going on. Haven’t you seen great strides in cables alone or are you STUCK in the 1800s. It makes no difference to (I suggest) millions that can and do hear a vast improvement over the last 40 years.

A FUSE in a valve amp that cold starts, may NEVER recover or cool enough to remove the resistance and chaos a bending and heaving thermal wire is offering from a stock fuse. NOT SO in a lot of after market fuses. That bit of thermal overheat I can hear for over an hour in most of my valve amps. The summer time they never recover. I bypass the fuse in the summer because of that reason. I’ve never lost a valve amp or SS amp by doing so.. 50 years. and 100s of amps. The fuse protect the equipment ONLY. Most mechanics know what fuses are. They are the point of preferred failure, certainly not a way to hotrod something.

None the less saying something is hogwash, is hogwash especially when it comes to cables and wire direction. It’s simple, cables sound and work differently in one direction than the other. The reason to condition cabling the direction it is pushed through the dies. It not only matters, it’s the difference weather I buy your STUFF or not.

Ted Denny hasn’t said a word, yet you bring up his products as if YOU tried them. I’d really doubt that one.. Great products at an astronomical price. Still great products with a FULL money back guarantee. There is NO reason for anyone to complain about that.. You don’t KNOW about a product so you get to slam it. No!

So we are clear I’ve NEVER paid more than 200.00 for the best cables on earth, or over 40 dollars for a fuse. That 40 dollar fuse was well dampened with almost instant thermal transfer. In other words, it NEVER had to recover, because it NEVER got hot..

It would be kind of silly to imply a 5 cent piece of thermal wire made no difference, you ever put a radial tire on backwards? Direction matters.. Even crazy GK new that.

It’s funny that us audiophiles sometimes believe we understand electronics better than electrical engineers do. If DCS, Pass, and other good brands ship their products with standard cables and fuses - shouldn’t we be able to reject the urge to upgrade those?

The fuse needs go in correctly or it will blow! If you put the fuse in backwards it will suck!

It didn't take long before the trolls, name dropping and appeals to authority came up. They make very poor substitutes for actually trying them. 

All the best,
Nonoise

One of the things about this hobby is you can extrapolate things to the ridiculous. Fuse direction is one of them. How do you know that by switching the fuse it is the metallurgy of the fuse with respect to the AC source that makes it sound different? Maybe it's the fuse holder. If you look at a fuse holder there are two connections -- one on the end and one on the side. There is no standard (or electrical difference) which connection is from the power inlet and which connection is to the transformer. Some manufacturers wire the inlet to the side and the outlet to the end and some do it the other way. So when you change the fuse direction and hear a difference, maybe it's the way it's oriented in the holder and that is why other people hear it differently or hear a difference with the same fuse turned around in different components.

I recall a conversation I had with Ken Stevens of CAT who said if you don't have the time or patience to evaluate a tweak... then save your money.

  

jasonbourne52

@mitchb : I see you have drunk the fuser Kool Aid! How can you believe this nonsense that a small piece of wire - which does not carry a music signal - can somehow change the character of a component - and cost hundreds! Enlighten me!

Ditto for power cables, with two exceptions. They can supply the needed current and the quality of shielding that encases the cable to contain mains noise.

This is gold, Jerry! GOLD!

Ignore the idiot posters here.

Mirror, dude.

@pdreher - I'm not sure what your experience is with My Pillow, but I like mine.  I'd recommend that you try one, but will warn you that they are somewhat directional like most pillows are after an extended break-in period.  Yellow fill is my reference.

I tried these purple and orange fuses and ended up sending those snake fuses back. Lord I love return privileges.

So @nonoise when you sticking one of these fuses in your Technique Inergrated .

No need to as it the Technics sounds fantastic the way it is. 👍

Op...you really need to try one fuse at a time.  Otherwise, you won't know which component sounds good or bad.  My beef with SR is that they don't tell you the direction.  With QSA fuses they do.  I have all QSA yellow fuses in my system.

I'd say have your significant other (if you have one) or friend install the fuse(s) so that you can't see them, play your favorite tune, then have the same person (for continuity) reverse it, again without you seeing it, play the same tune and realize there is no difference and you wasted your money.

May I suggest something that might help?

Wipe both ends of the fuses before placing them all in the devices in the same way (i.e. writing left to right, or otherwise, your choice). Secure them in place, switch on the device and play the music. Thereafter I strongly suggest you let the fuses be.

IF you feel the need to experiment give it at least two mins operating time before changing.

(I was given designer fuses and installed them in my DAC & phono. They work very well, no audible differences though.)

 

Never keep reversing the fuse, NEVER wipe the goo off the fuse, NEVER.

Install the fuse and let it play if you think it's wrong, wait for at least a day. Then with fresh ears reverse the fuse. IF it sounds better leave if it doesn't put back the way it was. 

The fuse holder should have been inspected before you installed ANY fuse and replaced if there is damage.

The main reason for a phono sections lack of change is because the very low current draw they have through the wires. I've rewired tone arms that took 500+ hours to break-in, the fuse took at least 1/2 of that time.

Power amps, put it in, if you can't hear a difference, get your money back, it's as simple as that. The better the Power supply the less you'll notice it..

Big Macs and Pass amps, LOL who has better power supplied? Not many.

Even Mcintosh finally got it through their thick heads, they SELL cables NOW and I'm a huge Mac fan. 

As I look across the very flat earth. It can't be round.

@jasonbourne52    You're clearly an intelligent guy who can sort out nonsense from fact.  Join my club.

@helmholtzsoul     Juice is juice.  No hope for you I'm afraid.  I've called the guys in white coats.

"It’s simple AC moves in a direction towards the source, period."

I thought it reversed direction 50 times a second.  Perhaps you should keep to the simpler DC?

OP, in the SR fuse packing it clearly states to insert the fuse from the S to the R. Or left to right.

The first thing to do before you take the hood off is power off and un plug the power cable from the back of the preamplifier/amplifier. 

Only insert one fuse at a time and the first fuse should be closest to the IEC inlet and the power train.

Insert the fuse, plug in the power cord and power on, after some period of time you will be able to tell by listening if the fuse is in the right direction. Since these fuses are directional they will sound strident if they are in the wrong direction. If so, power off and un plug the power cord and simply reverse direction.

All the above applies to both your preamplifier and amplifier and my experience with the SR Purple fuses.

And please, don’t listen to the naysayers. It’s your rig and your money. Besides I’ve learned that the monitors here on Agon don’t mind and possibly prefer some spirited debate.

Especially with the so called know it all testers. You know the ones, that only believes something if and only if it’s measured some sort of way. There is nothing wrong with using your ears. Everything is not new audio part bias. As if.

These are the same electrical engineers who don’t believe in cryo treating metals works either even though the aeronautical (engineering) industry and others have been using these techniques since the 30’s, all the way down to the of tiniest parts molecular level to some of the most massive parts for rockets and jet engines.

You will find that in some fuse positions there may be no effect at all. That is one of the reasons to test each SR fuse at each separate position one at at time using only one SR fuse at a time with the original fuses. Is it time consuming? Yes. But you will find that in certain fuse positions no new or SR fuses are needed. As the original fuse is fine where it is. But that comes from a lot of trial and listening. 

And the ones you find you don't need, send them back for a refund before the 30 days are up. Just so you know, there is a buy two get one free sale on SR fuses for the month of April/2022 and they can be mix/matched too.

 

 

An there's the rub. You THOUGHT, but not quite long enough. It's ok you are the very first one to ever say that. If you keep walking you will fall off the edge.

I really thought this forum after all these years had finally turned the corner. It's stereo equipment. We (mechanics) put them in the dash of vehicles and install generators as big as a pickup truck to power 400 stereos as CES. I work the shows that supply the power for the equipment. DC? That is just one side of most heavy equipment.. 

Mechanics PLAY with stereo equipment. I can honestly say, most first year apprentices have enough skill to be a very good stereo repair person. He/she only has 3 more years to Journeyman (to be a mechanic), one more for Aviation or Marine and then 2 more for his masters.

DC is HARD it stumps more people than you think... Most AC guys haven't got a clue with marine electric. AC/DC.

Most mechanics I know were building amps as kids and cars as teens.

BTW it does the Cha Cha 50 OR 60 times per second. You stand still when you dance? That must look weird. :-) The Conga line MOVES forward and then back, just like AC, always towards the source.

AC on the outside, DC on the inside. That was a tough one to learn..

Even crazy GeoffKait new that...

@helmholtzsoul, My man! Lol!

I understand you brother. As I know a bunch, and I do mean a bunch of Powerplant and Avionics Journeymen [master craftsmen (and women)] who work in the Aeronautical industry who were once called ’mechanics’. And these professionals fabricate everything on a rocket or a plane. Has anyone ever heard of Pratt & Whitney, Rolls Royce, Boeing?

Where I sit, mechanics of nowadays are more akin to surgeons than the stereotype of what a mechanic looks like and may be to some..

And to my naysayers and especially to the monitors here on Agon who showed me that it’s ok to debate here in a respectful like manner. How do you like me now?

Speaking of geoffkait, I think he's back? There's a @geoffkait20f6 and he sounds like geoffkait cause he just happened to mention NASA grade ceramic of DH Cones, speaking of Aeronautical Engineering? geoffkait is that you?

So you fusers: the red fuse or the blue fuse. Which sounds better? ... and the ones that Mother gives you don't do anything at all ... Go ask Alice ...

In the educational information about purple fuses, Ted does say something about its mind bending properties.

I’ll let that one go through to the wicket keeper.

Fuser? George is wearing glasses again. It is bright down under. I know rectifier valves are not in the signal path so they can't affect the sound. OK!! You win..

You're smarter than me.. 

Now time to get ready for work.

BTW oldhvymec sends his LOVE to all. He say's it is COLD and WET. The Fins are ready and so is the crew. He found a rabbit of all things, of course he's trying to figure how to get it home.. They EAT rabbits over there, A LOT.. I don't know how that is going work out if someone eats his rabbit. WWIV the heck with WWIII. :-)

      Inescapable FACT: No one understands exactly how electricity works.   

      That’s why there’s so much Electrical THEORY.     

      The number of Wiki-Scientists on these pages, attempting to win the IG-Nobel Prize in Pseudo-Physics, is always amusing.           

      Whenever some educated someone actually does discover exactly how electricity does function, they’ll be lauded by the scientific community, will have solved some of the disparities between Relativity and Quantum Mechanics, receive a Nobel and we’ll hear about it.     

      Newton’s THEORIES were largely superseded by Einstein’s, then came Feynman’s.       For now; none of you can categorically prove your statements (theories), regarding fuses, wires, or anything else, as regards our systems.    

      The following are for your edification/education/correction (which is why most of you won’t bother to read the links):

 https://www.thegreatcoursesdaily.com/how-einstein-challenged-newtonian-physics/     

 then: http://hyperphysics.phy-astr.gsu.edu/hbase/Forces/qed.html#:~:text=Quantum%20electrodynamics%2C%20co....      and: https://bigthink.com/philip-perry/an-updated-feynman-experiment-could-heal-the-rift-between-quantum-...                         

      Happy listening, even to those that refuse to follow the scientific process of observation and experimentation, in their own systems, with their own ears, FOR FREE (ie: 30 day return policy, from some manufacturers).

I have not tried any boutique fuses, don't know if they make a difference or not.

But I would really like to hear from the 'philes that have heard differences, in particular what are these differences?  I honestly don't think my ears are up to the task.

Regards,

barts

 

Happy listening, even to those that refuse to follow the scientific process of observation and experimentation, in their own systems, with their own ears, FOR FREE (ie: 30 day return policy, from some manufacturers).

@barts, how will you know if you don’t try? There are literally thousand’s of posts here on Agon alone that describe what they hear and how to do it. You don’t need an uber expensive fuse either. Try the Acme Special Coated Audio Labs Silver Cryo Fuses at $20 a pop.

Your ears are no worse than some of our long in the tooth members here, including myself.☺ It sounds as if you’ve already talked yourself out of trying. What’s the expression? Nothing beats a failure but a try? Remember this is a hobby and it’s supposed to be fun!

 

Ya puts the fuse on a perfectly level surface plate, then flick one end with the nail of your right index figure.  If it flies off the surface plate and breaks on the floor, you've got a bad fuse.  Better luck next time.  If it stays on the surface plate, select the end of the fuse that is pointing away from you and stick it in first.  I won't insult you by telling you where to stick it.

Placebo effect at work.

None the less saying something is hogwash, is hogwash especially when it comes to cables and wire direction. It’s simple, cables sound and work differently in one direction than the other. The reason to condition cabling the direction it is pushed through the dies. It not only matters, it’s the difference weather I buy your STUFF or not.

Ted Denny hasn’t said a word, yet you bring up his products as if YOU tried them. I’d really doubt that one.. Great products at an astronomical price. Still great products with a FULL money back guarantee. There is NO reason for anyone to complain about that.. You don’t KNOW about a product so you get to slam it. No!

Quite the word salad! Complete with self contradiction. Apparently the comment about Ted isn't directed at me; I didn't bring him up. But coincidentally, we've been playing some Synergistic speaker cables in the shop for the last month. Our customer that brought them in exclaimed how they were so transformative. We ran a comparison, just for fun, between them and our shop cables, which we made up from 10ga oxygen free copper wire. Everyone in the shop was challenged to hear a difference. Our speakers though are 16 Ohms and speaker cables are far less critical when driving 16 Ohms as opposed to 8 or 4 Ohms.

It’s not a question of truth, it’s a question of weather you keep up with what the heck is really going on.

Priceless! 🤣

Spoiler alert: Truth is what is going on.

 

@tyray 

No, I haven't talked myself out of trying fuses, I just haven't talked myself into trying them.  Partly because the four ARC amps I use to power my tri-amped system have seven fuses each.  So, that's 28 fuses just in the amps. And then another 5 in the front end, for a total of 33.

You can see where that would get pricey very quickly especially if your talkin' SR fuses.  I appreciate the Acme fuse suggestion, so that would only be $700 to do them all rather than the >$4000 variety.

Honestly I don't need to be reminded that this is fun.  It's all about the music to me not the nth degree of what I can get out of my system.   

Regards,

barts 

Hello @barts 

I've accumulated about 5 different brands of low cost, aftermarket fuses (I'd never pay what SR charges, but that's just me) and in my Marantz PM-15S2 and SA-15S2 SACD player there was a distinct difference with all of them, directionally and in comparison to the bog standard ones. With my Kinki EX-M1, I could hardly tell the difference so I kept in the standard fuse that came with it. 

The "sound" when in the wrong direction always rolled off the highs, muted ambience, and gave an out of phase shading to the sound making it harder to locate placement on the soundstage, or kind of a slight blur. If one didn't know, they'd be content with the sound and attribute it to some house sound (like warmth or richness). In the proper direction, everything snaps into place, the highs extend more and ambience is restored, along with better definition and detail. That's been my experience with every fuse I've tried with the Marantz gear, but not the Kinki.

All the best,
Nonoise

Hi @nonoise 

Thank you, that is exactly (and succinctly!) what I was looking for.  I will get an itch to give fusses a go at some point.  I have bigger fish to fry at the moment, as in interconnects.  As you might imagine I have a bunch due to the four amps and external electronic x-over.  

Regards,

barts

Clearly the orange fuses combine the best qualities of the red fuses and the yellow fuses, while the purple fuses combine those of the red and the blue.

I have been in this obsession (euphemistically, a "hobby") for some 50 years and I can still hear the better part of the human range. The SR Purple Fuses are major --  repeat major -- audible improvements, both in my VTL 7.5 iii preamp and more latterly, my Sansui TU-X1 tuner (ca. 1979), often regarded as the finest tuner ever made.  I am beyond audio "snake oil" and can hear --  or not hear -- the difference.

I don't know the physics, but with my simple but experienced ears, I do know you have to tell which fuse's end is in and which points out, to hear which way is better. Neal