janneman said:
This sounds like a fast blowing semiconductor protection fuse, with the wide element and filling. The filling is there to fall into the break and eliminate the multiple reconnections possible during a normal fuse blowing event, which gives the semi it is protecting a chance at survival.
I doubt this is a specially designed "audio" fuse, more likely a standard part in one of the fuse manufacturers line. It's not worth expendiing any effort finding it but, I'd guess it probably retails for a small fraction of the $55. in the real world.
Mike
Variac said:
The bashing in this thread used to tick me off in the first year of it's existence, i have the highest respect for successful audio designers, likely because there's hardly anything/anyone else to be inspired by.
The alternative to this paradox is a gathering of traditional Oxford professor types, each day attempting to expose and derail their loathed collegues with their vast knowledge and undisputed academic superiority.
(or chasing eachother with an axe across the baby bottom smooth trimmed limy lawns, dressed in scarlet pimpernel robes and show me your willy serving tray caps )
The routine can also be viewed at as a daily requirement dosage, merely disrupted on occasion by youths making up for age with pseudo-scientific gibberish or the ramblings of a twit philosopher.
Much more fun.
john curl said:
Lots of prejudice in that statement. The Schmook/Gilbert mult-tanh input stage when integrated can be made identically flat over its operating range. Combined with the super bootstrapped differential VAS one could approach an op-amp with 0 distortion.
Better yet it's almost 40yr. old.
MikeBettinger said:
Mike,
I'm pretty sure it is a standard metal wire fuse, but with a flat wire. To be sure, 'normal' commercial fuses have the same flat wire, depending on the break speed and current rating. Look a any high current Bussmann for example, it is a very standard technique, including the filling with something that looks like sand. I blew enough of these critters to know how they look inside
My distributors has similar fuses for $2 for 10
How's that for mark-up?Note also that the claimes given are not more than marketese as they are unsubstantiated and use pretty ambiguous language, as is customary in such cases.
Anyway, what I wonder is this. Assuming that there is an audible difference, that would mean that such a fuse modifies the signal at the speaker jacks, as compared to the same but non-audio fuse. And change it to such an extend that it becomes audible. How could such a signal change come about?
Jan Didden
janneman said:
If there is an audible difference I would guess if would have more to do with the fact you have disturbed the connection while change out the fuse. Inserting the new $55. fuse does make an audible difference for the careful listener, maybe even for the better, but was it the fuse or swapping it out that the discerning audiophile is hearing? My vote would be the swap. The fuse should be relatively benign until it starts getting near it's rated amperage and starts heating.
I have an interesting book on contact theory that discusses many aspects of connections and would relate directly to this; not to mention suggesting mechanisms that might account for what one is hearing during cable break in and the effects of time and the environment on connections. Good stuff.
I doubt another copy could be located but for the record it's called The NEY Contact Manual, Electrical Contacts for Low Energy Use. By Kenneth E Pitney. Copyright 1973 by The J.M. Ney Company. It was distributed as company pr stuff.
Mike.
I'm impressed by the attitude expressed here by many. Also, the 'mind reading' of my true intent by the moderators.
It is not just me who is disparaged, but virtually the whole high end audio community.
When I speak of autos, tires, etc, almost always it is to create an ANALOGY in order to make a 'difficult' concept more understandable. Yet, my ANALOGY will get pulled and an INSULT will stay intact. For example, where was the PUT DOWN in my tire analogy comments that were pulled recently? You know, I really work to find a way a expressing something to people with less experience. I am truly insulted, when it is derided and censored.
I may be made a 'laughing stock' here, but I am a very successful 'laughing stock' in the audio field. Many here will not be so successful, even if they are more educated, use more 'exotic' circuits, or get 'better' measurements. Wait and see.
It is not just me who is disparaged, but virtually the whole high end audio community.
When I speak of autos, tires, etc, almost always it is to create an ANALOGY in order to make a 'difficult' concept more understandable. Yet, my ANALOGY will get pulled and an INSULT will stay intact. For example, where was the PUT DOWN in my tire analogy comments that were pulled recently? You know, I really work to find a way a expressing something to people with less experience. I am truly insulted, when it is derided and censored.
I may be made a 'laughing stock' here, but I am a very successful 'laughing stock' in the audio field. Many here will not be so successful, even if they are more educated, use more 'exotic' circuits, or get 'better' measurements. Wait and see.
john curl said:
I totally agree.
Not many can bragg being a 'laughing stock' or even bieng considered a 'problem' by a few who have less brains.
But in this case, but surely not at all in other audio amplifier field matters,
I feel I can understand you situation very much, John.
I agree 100% with you quote above.
Without dear John Curl
this forum would not be the place that it is.
And this is meant by me in a very positive sence.
Thanks, JC, on behalf of Lineup as a reader of your stuff
and I know on behalf of many more thinking like me.
Thanks!
/your Lineup, Sweden end of May 2009
Getting back to 'factual' information. Scott, would you like to describe the transfer function of a multi-tanh input stage? As I recall, when I first noted it in IEEE 'Solid State circuits', that it looked pretty ragged, even if more grossly linear. THIS is supposed to supplant FETS? OR TUBES? Not in my lifetime.
However, Scott, why don't YOU start a tread on these NEW topologies? Do you feel that people can actually utilize them in some way? That they can do this in their basement? Please, let's be practical here.
However, Scott, why don't YOU start a tread on these NEW topologies? Do you feel that people can actually utilize them in some way? That they can do this in their basement? Please, let's be practical here.
Who belongs to the high end audio community here? Have you talked with all of them and they agreed to let you voice their opinions?
Who is deciding the difficulty of a subject? Maybe it's easier to understand today than it was 40 years ago?
Could you define "success"? Are you expecting your definition to be accepted in a DIY comminity as much as e.g. in the audio magazines?
Have you identified here any attempts to get success in the audio industry and you feel threatened?
MikeBettinger said:
Yes I know that effect, it often occurs also when changing connectors and/or interlinks. That's why I give such attention to mechanical fit and consistency, and still when changing cables after 6 months there is sometimes an effect.
But fuse contacts? We're talking about something in series with the primary of the xformer. Together with the power switch, for instance. Do we hear a difference after every power-up, because there's always a slight difference in the final contact pressure variation?
Does the fuse contact variation actually have a measureable effect on, say, the secondary rectified voltage? And if so, does THAT in turn have an audible effect, assuming a competently engineered amplifier?
We're anyway speculating here because there's no indication whether there actually is a difference or not, with what equipment, under which circumstances, etc.
As I said, I fall for it again and again
Edit: The contact manual can be downloaded from the company site after registration. Free. Thanks for the link.
Jan Didden
No, the date is 1998 and I do have a copy. Complimentary versions of his circuits follow pretty obviously. I know it's still an op-amp/feedback but one with a linear transfer function over say 25-50mv could be shown to be free of the dreaded PIM also. Barrie does not extend this to op-amp inputs because he is more interested in open-loop RF circuits these days.
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