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

Showing 34 responses by uberwaltz

Merry Christmas and Happy New year to you and your family too George.

And too all Audiogon members old and new!
Great review David.
And if I am not mistaken SR did a similar deal last year whereby you received a free Blue fuse upon purchasing a Blue duplex.
Pretty sure it was just before Xmas as now.
Intrigued as my Ayre EX 8 uses..... Three fuses....
🤔🤔
George
Dident Momma ever shout to you down in the basement that if you got nothing nice to say then say nothing?
George.

Are you suggesting that Ayre do not sell their equipment cw Myrtle wood blocks?
Just peruse their website and go to the ex8.
Come back and tell me what you see.....

Oh and $6k is bare bones, fully loaded they are $8.5k.
Just for edification.

But alas I am afraid your increasingly irate posts are not on topic so could you please refrain from getting yourself all worked up and let us get back on point.
Thank you
Wrong again, do your homework, yes it’s passive, yes it’s mains powered or can even be battery powered.
My apologies George.
I wrongly assumed there would be no mains voltage involved in a passive device.
Thank you for enlightening me.
Boxer
What George is trying to explain is that the Lightspeed Attentuator is a passive product.
Hence no fuses as no mains ac is used.

The rest is just a little bit of extra vitriol for good measure.
Thx Boxer.
Sort of wish I had a Pass amp so it might be a little more relevant to this thread of David's.

But I think my Ayre EX 8 is no slouch.

One interesting aspect of Ayre was when I rang them to confirm fuse size they were extremely enthusiastic about both aftermarket fuses and wooden blocks underneath the amp.
Indeed the ex8 is sold cw three Myrtle wood blocks right from Ayre.
That right there says a lot to me about an enlightened audio manufacturer.
I see George.
So now you are recommending that users( fusers?) should change the fuse while live?
That's not really a very good idea you know.

I am afraid I will have to decline to follow your recommendation in this instance but I do thank you.
Well my SR Orange fuses were waiting for me when I got home from work travels and one is in the amp right now cooking a little.
The other one is for the CD player but I need to open that one up replace, gosh who do I need to call to make sure I do not hurt myself whilst performing this dangerous task?
Ah yes, Ghostbusters!
Now George
Your negative cynicism is not helping the thread at all.

I will only report what I hear.

I hope it will be good but you do not know until you try.

Would not be the first tweak that I heard negative results as I did with solid copper core speaker cables that had to be returned as just plain awful in my system.

It will be a fair and subjective review of the effects in my system.
I do not know that yet George so I cannot comment yet.

But thank you for the enthusiasm!
Means a lot!
how did you even read that as an excuse?
I personally could not care less whether a manufacturer shows up here and posts or not.

I will be reporting my experiences of the new SR Orange fuses shortly.

Peace......
And just because they choose not to do so ( for whatever reasons that none of us are privvy too),  that means their product does not work?

I think there is a fatal fallacy in that train of thought.
imho
George
Thank you for the reply.
However you just cannot make that statement I am afraid.
All you can say is they did not work for you
All Wolf can say is they did not work for him.
And I do not disbelieve either of you when you say that.

BUT....
You cannot say they do not work for me.
You cannot say they do not work for Frank.
You cannot say they do not work for David
You cannot say they do not work for Nonoise.
You cannot say they do not work for the rest of the users who are using them.

It is not a blanket statement you can make.
You cannot hear our systems.
You do not know our rooms
You do not have our ears ( for better or worse)

I fail to see what a manufacturer coming here has to do with any of the above or your arguements tbh.

Peace......
George
Just as an FYI.
If my post had been all caps then yes that would have been a "yelling" post.
But when just one word is in caps it signifies a highlight of that one word ( or more than one in this instance) within said post.

Just wanted to clear that up as I was most definitely not yelling at you George, life is too short.

However I am interested in the Gryphon story as I do not think I have read that from you before and it is actually very relevant and thank you for that.

As I have clearly stated many times, if people have tried something and found no difference or change or even worse it made matters worse then that is what it is.
A result that they perceived they heard or not heard whichever the case may be.

So both yourself and Wolf have tried or been party to trying of aftermarket fuses and did not consider them a worthwhile sonic benefit.
That is perfectly fine and a report of what you discerned.

It does not of course mean they are a waste of money and do not work period, just they did not work for you guys at that time in those systems.
And you cannot say any more than that.

IME premium fuses make a very audible difference. If you don't hear an improvement, so be it, at least you actually tried it. You did try it, right?
Unfortunately Boxer, Georgie is on record as categoricaly stating he has NEVER tried a boutique fuse and NEVER will.

Now that is just a perfect example of a closed mindset.
I truly do not see what he has to gain by even posting on these types of threads as he has no interest in the betterment of audio enjoyment by said tweaks.

It grieves me to see such discord between fellow audio enthusiasts tbh.
George
You truly do not get it but thats fine, everybody is entitled to their own opinion , not that you appear to have worked that out yet.

So as a result of all the high praise reported here I decided to order 2 SR Orange fuses and see if I can hear a difference between them and the SR Blue fuses currently in use right now.

Hold that thought.
Not that it really matters as a certain down under participant is likely laughing himself to sleep right now as he has achieved exactly what he set out to.

A real shame that some cannot see that......

Sorry David, we fell prey to evil machinations and have messed up your once most excellent thread.

Hopefully it will revive, after all it can only go uphill from here.......
Then do your job correctly please Audiogon, there are MANY posts in this thread that fit the description you just laid out.
Or just listen to certain whining members....
Whatever.....
Thank you
Newsflash
Georgie....
No matter what , a post has to be reported first before it is removed as long as it does not contain serious swearing which I think is automatically removed.

So wonder who does the report.......
And it's the same old magic circle hater club every time, that come up with monotonous regularity.
And we thank you for the thread and the information contained within David.
Confirms my findings but on a much more organized scale.
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......
😇😇😇
C'mon now George, you can do better than that!

Maybe keep off the Dingo meat........
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........
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.
😁😁😁
Same old haters, nothing has changed.
Except possibly a little more desperate....

Modjeski actually did find the Tuning Fuse he tested measured differently than the Little Fuse brand he routinely uses. The difference was on the order of 120dB down ;-) . If your system can reveal that, and your ears can hear it, congratulations, you do indeed have a mighty fine system and golden ears.

Yeah, I know not everything that can he heard can be measured. But for a fuse to effect the tonality of a system? C'mon, man, you know that's not possible. A fuse doesn't know about tone, any more than an acoustical instrument knows about electricity.

As for fuse directionality in an AC application, that defies what used to be called common sense. Yeah I know, what about all the people who insist to hear a difference when the fuse is reversed? I have no idea (mechanical issues perhaps), but people also claim to hear God talking to them. Do you?

I must say I am a little surprised to read this Eric, I had thought you were more open minded than that?

A few years ago I could have penned that until a member here( who does not list any longer unfortunately) sent me a SR Black fuse he had replaced with a Blue fuse in his dac.
I had the exact same dac.
First try I was not impressed, it really was no better and if anything worse.
Try it the other way he said.
After I got up off the floor from laughing I though oh well why not!

Say what?!?!
Who swapped my dac for a much more expensive model!
I have been open minded and receptive of tweaks ever since.

And yes George and Wolf you can run your normal belittling routines.
It's not going to have any effect on those who hear a difference.