Pass Labs and Fuses


I continue to enjoy my Pass Labs Int-60 amplifier with my horn based system. My listening area has been intensively treated for acoustic - speaker interaction and it is always a joy for me to listen to a Dialed In system.

For my latest listening experiment I decided to evaluate the sonic differences using three fuses in the Pass amplifier. A brand new Bussman fuse, a Synergistic Research Blue fuse and a Synergistic Research Orange fuse. I keep this amp on 24/7 as suggested by the manufacturer. The Blue fuse has over a 1000 hours on it and the Orange had a 160 hours (continuous playing time) on it before any listening evaluations. The Bussman was listened to for the first time immediately out of the box.

The Bussman fuse did a fine job. But going from the Blue fuse which I had been using to the Bussman, there was a definite change. With the Bussman the sound was now more two dimensional. Instruments were not as full bodied. The depth of the soundstage was compressed front to back. I was more aware that I was listening to a recording versus being in the room with the musicians. The music was less emotionally involving. I did for completeness sake reverse the direction of the new Bussman fuse several times. It did consistently sound better installed in one direction, not huge but it is there.

Comparing the Synergistic Blue Fuse to Orange Fuse was similar to my past tube rolling experiences with my 300B tubed amplifier (but cheaper to carry out). Different tubes change the sound and these different fuses change the sound. Both of these fuses brought out more of the music that the Pass Labs amp was playing when compared to the Bussman fuse. Before any serious listening was undertaken, the fuses were evaluated for best sounding direction - and they both were directional.

The Orange fuse really is exceptional in it’s ability to let me enjoy the music and who is playing what. The detail of Willie Nelson’s nylon strings on his guitar had much better dynamics and richer texture than I have previously heard using the Blue fuse. His Stardust album continues to impress me.

When listening to music that has more musicians playing, such as on Sierra Una Noche, I can more easily distinguish each instrument and it’s contribution to the musical whole. Also in this live recording that uses only two mics, I get a better feel of each musician’s distance from the microphones and that they move toward and away from the microphones while playing. These factors allow me to forget I am listening to a recording of an event. With the Orange fuse, I feel I am at the event as it is playing.

This fuse experiment was fun to do and educational.
Feel free to call.

David Pritchard
575-644-1462

128x128davidpritchard
Witnesses can easily be biased or just flat out get things wrong, especially the details, which is mostly what differences in sound are all about.

Also witnesses all vary in regards to credibility. Some are way more credible than others based on track record.

Yes, there's always that negative to prove. Quite the argument. So many ways to go when the correct way was done some time ago.

All the best,
Nonoise
You observe, you report. You run it up the flagpole and see if anybody salutes. Those who have the ability describe the details of what they observed. Everyone else, the grumblers and whiners and left behinders, can go pound sand. Everything is system and listener dependent so results vary. End of story.
Regarding directionality, I would remind everyone that in past fuse-related threads there are two members who have cited actual experience rotating the position of a fuse in its holder without changing its direction. Namely Atmasphere and SGordon1. Both gentlemen reported that doing so resulted in audibly significant sonic consequences. Based on his experiments Ralph (Atmasphere) also stated that ...
Reversal is improving the contact area because fuse and holder are not dimensionally perfect and the fuse might sit better in the holder in one direction. By rotating the fuse in the holder without reversing it gets the same effect only more profoundly.
If so, it would seem to say that many and probably most of the reports of sonic differences occurring as a result of changing the direction of a fuse are accurate, while assertions that it is impossible for a fuse to be intrinsically directional in an AC circuit (which I believe to be true) are also accurate.

In any event, it seems to me that dismissing the findings of these two gentlemen and/or Atmasphere's explanation of those findings on the basis of conjecture, rather than actual experience, is no less objectionable than dismissing reported findings of directionality on the basis of conjecture rather than actual experience.

Regards,
-- Al

Yeah, sure, Al. You guys keep bringing this issue with the fuse holder up and I keep shooting it down. The fuse holder theory, assuming It’s true, which I seriously doubt, is that it would be random, whereas directionality of the fuse itself is not. It’s always the same direction that is superior, for ANY given fuse.

The “correct direction” for any fuse is in the direction of the lowest outage drop. For anyone with ears the correct direction of the fuse exhibits much less noise and distortion than the incorrect way. Differences in the fuse holder end, if any, would not (rpt not) exhibit these rather dramatic differences. This is all just another example of you can’t teach an old dog new tricks. But thanks for reminding us of this silly theory, anyway.
bdp24, thanx for making sense. Both Nelson and Roger have access to serious test equipment. I think over the years they have established which measurable anomalies sound bad (IM distortion) and which are euphoric (harmonic distortion). Nelson admits to adding small amounts of harmonic distortion to make his amps sound like tube amps. I suspect John Curl does the same thing. Having played with and measured hundreds if not thousands of circuits I am sure they are quite aware of what alterations do absolutely nothing like fancy fuses. 
I do not know what it takes for people to understand the power of our central nervous systems to modify perception. All our senses, hearing included are adjusted by our central nervous systems to perform well under various circumstances. Emotion can also make changes which are measurable. This is how lie detectors work. The fact is, if you think something will sound better or worse it will and it does. But the next time you are in a bad mood it will sound awful. 
And Uberwaltz, I am not criticizing your hearing or the CNS behind it. I am just giving you the real reason behind what you think yo are hearing. The operative word here is, "think."
I wonder what the measured difference would be by just rotating a fuse in it's holder. Two well respected amp builders have heard for themselves a difference in sound from a part of the amplifier that they say has no effect on the sound, just by rotating a fuse in it's holder.

Well, which is it?

Members here, cite these gentlemen as being above reproach and line up behind them in their arguments, other than to claim a form of neurosis on the part of those who hear a difference.

It's been said that the HiFi Tuning reports findings of a difference in directionality aren't enough to justify the difference in sound but what if the differences were in the same, or similar, amounts, to rotating the fuse in it's holder? Better yet, what if the measured differences in directionality are larger than just rotating a fuse? How would the argument go from there?

My bet would be that they'd double down on the insanity claim and still, never try it for themselves. 

All the best,
Nonoise
Uh, nobody said the very small differences in voltage drop explained the differences in the sound. In fact, HiFi Tuning states that fact themselves in the fuse Data Sheets on their web site. Which every yahoo and his brother would know IF they had read the Data Sheets. 
People sure are dumb. - Gomer
The new SR Orange fuses are doing just fine in my system at the moment. They have provided more clarity, better dynamics, and more realism overall.

They put this lady in the room front and center:

https://www.youtube.com/watch?v=ukO46Fibzi4

Highly recommended.

Frank
I have enjoyed my experiment to see if three different fuses would affect the sound in my Pass Labs INT-60 amplifier. To my brain they did.

My next experiment will simplify things a a bit more. Today I ordered the Nelson Pass First Watt SIT-3 amplifier. This will be compared to the First Watt F-7 using stock fuses and boutique fuses. So two similar very low part count and simple circuit amplifiers will be used to compare the difference between two different type.output transistors. Then stock and boutique fuses will be tried in both. 

The SIT-3 amplifier arrives this Friday.

The test will be partially blinded in that my Mother will be the listener and she is legally blind. The new amp if she likes it, is her Christmas present.

This will be fun.
David Pritchard MD
In a few of my posts regarding fuse mythology I've asked the question, are all of the wires used in a component sorted for directionality? Wait...I think I know the answer: the answer is no. Moving on...Is the wiring in that jumble of direction chaos possibly self canceling as regards directionality advantage? If a fuse's directionality benefit meets wire (and PC board traces) installed in this random order of direction, how does reversing it (remember, it's generally a tiny little wire relative to the wiring and traces in the component) audibly help things? The likely answer could be "somehow it does" if you spend 150 bucks or so...and remember when reversing the fuse to its supposed audibly "phase correct" position, you should reverse and test all the wire and PC traces (!) in that component as hey, ya never know. Now get busy...
Mods!!
This thread, needs to be shut down, it's turned toxic just like all other fuse threads have. None, not one, especially SR fuse manufacturers have come onto these forums to stand up to what BS they (and the magic circle club) say these fuses can do
 
And it's very dangerous for non technical to be playing around with ac mains fuses, and trying them in different directions frantically, forgetting just once to unplug mains before touching the fuse. 

Cheers George
The ONLY reason any of these fuse threads turn "toxic" is because of people like YOU GEORGE!
Now why don't you be a good boy and run along , this is the big boys play pen.
😁😁😁
And it’s very dangerous for non technical to be playing around with ac mains fuses, and trying them in different directions frantically, forgetting just once to unplug mains before touching the fuse.
And this is getting so old, trite and worn out it needs addressing before it is regurgitated yet again by George.

Have you ever changed a fuse in an amp George?
You know, where you pull out the fuse drawer at the back WHICH DISCONNECTS THE FUSE FROM THE AC POWER NO MATTER WHAT?
Or screw the black cap container head off type?

Granted there are some amp and equipment around that entails opening up the casework to get at the fuse but do you TRULY think anybody who is going to do that will really have left it plugged in and switched on???

Not everybody is as dense as some people George......

Let me put it another way..

If I was going to choose between reading and believing posts from David Pritchard or Georgehifi.......
Well do not hold your breath George........
C'mon now George, you can do better than that!

Maybe keep off the Dingo meat........
Somebody help me out. Are Georgie Boy and Wolfie the same person? Or do they just drink from the same water trough? Come on guys, lead, follow or get out of the way. 
Boy this is fun. George and Wolf hang on. These guys are talking a bunch of innocents into wasting their money on silly fuses and other misc JUNK. We are on the right side of history. Thinking that a fuse is going to make a difference is s___y and s----d to be polite. But these are the depths to which these people will dive to make cheap incredible, fabulous, unquestionable, dramatic and huge improvements in sound quality when all they need to do is get a new set of loudspeakers and one of Ralph's amps to drive them:)
No, it is like saying that someone who saw something in a scene a year ago, then saw the same scene today and claimed they noticed some minor change, has less credibility than someone who is comparing two pictures. Sort of like how people with "photographic" memory will regularly "remember" something in the scene they just saw that was not there.

That's like saying an actual witness to an event has no more credibility than one who hasn't. It's a word game now, and has been for a great while.



George,

If you object to a post, just report the post. I don’t understand this need to censor people for their views, whether they are wrong or not. People are adults here. I think they all understand electricity can be dangerous.
georgehifi6,325 posts12-04-2019 3:40amMods!!
This thread, needs to be shut down, it’s turned toxic just like all other fuse threads have. None, not one, especially SR fuse manufacturers have come onto these forums to stand up to what BS they (and the magic circle club) say these fuses can do

And it’s very dangerous for non technical to be playing around with ac mains fuses, and trying them in different directions frantically, forgetting just once to unplug mains before touching the fuse.

Cheers George

As always, you are welcome to try Synergistic Research Fuses in your system for 30-days risk-free and return them to your SR dealer for a full refund if you are not completely satisfied.

Sold with a no-risk 30-day money back guarantee

Doesn't SR return policy take the risk out of trying them?  If you can hear a difference, keep them, if not, return them?  What's the problem?
Geoffkait with two f's. Do you ever say or do anything useful? This is a rhetorical question that can not be reasonable answered in English. Any one here speak Mandarin? Geoffkait , you need to audition for a Quentin Tarantino movie. 
There sure is definite signs of toxicity on display today.
First time I have to agree with George!
Not likely to get better anytime soon.

Good to know which camp you fell into Mijo, I figured you for a little more receptive given your normal intelligent postings , even if they can be abrasive.
Oh well......
😇😇😇
Anyone who can’t hear the improvement in SQ afforded by SR Blue or Orange fuses over stock fuses should find a new hobby.

Those who knock aftermarket fuses without trying them for themselves need to find a new website to whine in where a lack of credibility is more acceptable than it is here.

Frank
I looks like I’ve picked up a new stalker. Welcome aboard, misogyn!

Side note: Frank, never one to miss an opportunity to shill, jumps right into the fray.
Frank
Maybe if they find a new hobby it could be restaurant reviewer (without tasting the food); or book reviewer (without reading the books); or movie reviewer (without seeing the movie).
Perfect new hobbies!
geoffkait ...

  • "Side note: Frank, never one to miss an opportunity to shill, jumps right into the fray."  

Geoff, if I said something really obvious like: "Hey it is raining." Or, "Gee, the sun is out." Would that be considered "shilling" for the weather? Stating the obvious isn't shilling, it is just stating the obvious.
-------------------------------------------------------------------------------------
gcdrum ...

Right, and these are the type of folks who will tell you that food is just a "fuel," and that sex is for procreation, never experiencing truly great food ... or ... 

Frank
As opposed to a restaurant reviewer who with two plates on the table, tastes one, then denotes the other one to be the best they have ever tasted if they only add a bit more salt to it.
I would like to David for posting his experiences on fuse swapping .

I like many others have experienced sound differences when swapping
fuses .  But before I did I was skeptical how could the power going thru a small wire ment to melt affect the sound ?  
( the same can be said with power outlets and cords )
hearing is believing !
When I experimented I didn't use $100 or $150 fuses ,
I used $2 , $10 and $20 fuses in both my amp and a guitar amp .
The first thing I discovered is that a ceramic fuse sounded better than a glass fuse , so I replaced all fuses in my system with ceramic ones 
for less than $25 .
I didn't like the sound of a gold plated cryro'd fuse or the audiophile directional one so I wasn't tempted to spend $100 or $200 on fuses .
I also discovered the HARD WAY that genaric cereamic fuses 
should be avoided both for reliablity and sound .
Spending a lot on a fuse was hard for me but when a 1/2 price sale 
on a Furutech fuse came along I had to try it .
Was it worth the price ? 
It did sound  better But for my pocketbook not enough to 
justify replacing the other 6 fuses in my amp .

In my opinion and experience fuses can and do affect the sound .
For me its a matter of the cost benifit ratio .





As the original poster I chose to perform an experiment that I considered fun and thought it was worth while to report the results.

 I chose the Pass Labs amplifier as their products do have the reputation of having a good power supply and being well built . I did not want to waste my time evaluating fuses in a product that has a questionable build quality. On all the Pass Labs amps that have fuses, the fuse is easily removed using a  screw in fuse holder which is next to the on -off power supply switch. I also considered this an important reason to chose a Pass Labs amp. I do consider safety to be important.

The experiment was not designed to be sales pitch for a new product but to examine if fuses in an amplifier might affect the sound. The test results I obtained revealed that three different fuses had three different effects on the sound, and that in each case simply removing the fuse and changing the direction of the fuse also changed the sound.

 I did not expect to hear a change in sound with the Bussman brand fuse. This alone made the experiment worthwhile to me. So for some audiophiles, simply changing the direction of the fuse may change the sound for the better. Fun to try if you have a fuse installed as the Pass products do.

 Since changes of fuse type and direction were made multiple times  an amplifier who's fuse  was easy and safely removable was a conscious decision that I made.
 
After spending many hours doing this, I thought it would be informative to the audiophile community to publish my results. I hope others will repeat similar experiments and report their results.

David Pritchard

And we thank you for the thread and the information contained within David.
Confirms my findings but on a much more organized scale.
At some risk of being flamed 🔥 can I point out that because of the rather long burn-in times required for fuses generally and the vagaries of fuse directionality, as well as possible fuse holder issues interfering, that any comparison or evaluation of fuses is by necessity a time-consuming affair fraught with all sorts of possible interfering conditions that might impose themselves on such a test and make conclusions questionable. Also, I think that it would be of value to select an amplifier with a reputation for a crappy power supply on which to experiment with fuses.
A couple of years ago I tested a pile of SR fuses just to give my ranting some credibility (!) and found they were useless and somewhat dangerous as their ratings were suspect. You can look it up...also, note that nobody responded to my previous post regarding internal wire direction chaos which, to my thinking anyway, negates fuse influence as described by the Athletic Supporters of fancy fuses. 
Wolf
Useless in what way. If you do not have measurements and triple bypass blind testing on everything with a reputable company I can’t believe what you are saying is true. You know the bias factor also comes into play.. The first thing I would want to know is how big a pile is that you mentioned. You see something else could of been in that pile that you used for a fuse. So come back with extensive documentation and I just might start to listen.
I am being sarcastic. I do hope you are enjoying your system even without those terrific fuses.
@oregonpapa   Frank, I see your Orange Fuse Thread up... and now down, again. Do you know why?
  • @oregonpapa   Frank, I see your Orange Fuse Thread up... and now down, again. Do you know why?

Nope. Don't know and don't care. I have way too much music left to listen to instead of worrying about a couple of nay-sayers getting their panties twisted into knots.

The SR Orange fuses are another advancement in after-market fuses. I loved the effect that the SR Blue fuses had on the system, but the Orange fuses are even better.

Frank
@oregonpapa Frank, I see your Orange Fuse Thread up... and now down, again. Do you know why?
Let me guess.....is the one behind it upside down compared to most?
Coriolis Force: "fictitious force that acts on objects that are in motion within a frame of reference that rotates with respect to an inertial frame." 😀
Let me guess.....is the one behind it upside down compared to most?

I guess that’s me, would be nice if I had that much influence from down here, I’d use it much more, with this malignant, snake oil, voodoo, rubbish.

And it's the same old magic circle fuser club every time, that come up with monotonous regularity each different color of the >$150 fuses sounds 100% better than the last.

Unbelievable they say, but make sure it’s around the right way, and had at least 100hrs burn in time, before you judge it!!

Even the non technical and gullible aren’t that stupid to be coned by this rubbish
georgieporgie
Even the non technical and gullible aren’t that stupid to be coned by this rubbish.

>>>>>Let’s see if we can figure this out. Did Georgie mean cloned? How about coined? Is that a contraction of corn pone? Is he referring to cone heads?🧑🏻‍🦲 👨🏻‍🦲
And it's the same old magic circle hater club every time, that come up with monotonous regularity.
And in spite of all of the nay-saying, the new SR Orange fuses are still sounding exceptional in my system.

Highly recommended.

Frank
Quick question, how do you know if it’s the Orange fuse breaking in or the eMats breaking in? Also, are they still breaking in? Does the system have to be ON for break-in to occur? How do you distinguish been what you hear with the Orange fuse and what you hear with the eMats? See 👀 where I’m going with this?
It has been shown that witnesses to staged crime scenes are notoriously unreliable. And the validity of subjective reviews of aural phenomena are equally suspect!