Not clear on how to tell which of the 2 fuses I should replace. Does anyone have an illustration or pic? thanks!
I think he’s referring to the fact that the DS has two fuses but only one is actually in the circuit.
Steve, that’s correct. I’ll assume I’ll figure out how to get the chassis open and locate the fuses, but I wasn’t sure how to tell which is the active/used one to replace.
thanks!
My recollection is that the active fuse is the one closer to the digital and analog boards.
To be sure, remove the other fuse and apply power. The unit should still power up.
Jonm…I think the fuse holders are marked digital and analog beside their respective slots. The analog slot is for a spare.
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Greetings,
What is the fuse specification for the Direct Stream JR?
Just ordered a JR this afternoon, and was curious as to (1) is a quality fuse used (even the $2 jobs are better than the 10 cent ones), and (2) what the fuse specification is?
Looking forward to receiving my new JR.
Thank you.
I’ve got an SR Blue fuse coming today, and I’m wondering about their statement that these are “directional”, and exactly what that means (if anything) on an alternating current line?
(It might be apparent that I am skeptical about the performance claims.)
Can anyone tell me what is the “correct” orientation for this in a DSD, or is that part just plain BS?
I’d just try it both ways and see if I hear a difference. If I don’t it doesn’t matter, if I do I’d know the answer. You won’t hurt the fuse or the DS in doing so.
This has always been the source of my skepticism of directionality of fuses in an AC circuit. But perhaps they operate as some sort of filter in one direction. Yet, if so, would not the manufacturer know and tell us? Regardless, as Ted notes, either it will make a difference, or not.
Please let us know what you determine.
In which case it would be a non-linear rectifier…
Yep!
Again, color me skeptical.
Me too. IMHO, the only likely difference I anticipate would be perhaps slightly more damping in the bass range, assuming that the SR fuses are lower resistance than the stock fuse.
Any effect at all remains to be seen.
At least it’s returnable.
Well it has to be non-linear, it’s a fuse, it’s job is to be more non-linear that any wire or trace carrying that amount of current, slow blow’s have to be even weirder. I suspect it’s less non-linear than el-cheapo fuses. Also remember that the waveform coming from your AC outlets probably isn’t symmetrical. For example half wave rectifiers (especially common in lower current audiophile products) only draw current from one side of the AC waveform and hence can flatten that side waveform somewhat. Whether these two things are big enough magnitude together to matter I don’t know, but we hear pretty small changes from other things in our audio boxes.
Ted, what do you mean by non-linear in this context?
In my mind, a fuse’s output is directly proportional to its input (should be the same, in fact) up until the point the current is sufficient to initiate its designed failure and consequential circuit protection. Only as the designed failure point is approached is the fuse non-linear to my way of thinking. (How fuses blow and avoid arcing, etc. is remarkably complicated and very cool.)
It’s a continuity argument - they are by definition non-linear (they blow), but near this point they can’t be entirely linear either. The interesting thing is what’s the definition of near - we use fuses near their limits by definition, we’re not a factor of 10 (or even a factor of 2) away from their non-linear point. Such factors are normally used in engineering to stay away from non-linarites (like breaking), with fuses we’re working near the edge. A slow blow fuse is simply an exaggerated version and it’s non-linear in time as well.
I guess I could add that most linear power supplies take most of their current right at the top of the waveforms, so that current is much higher than the fuse’s nominal current limit… A fast blow fuse is in some sense still a slow blow fuse, but on a smaller time scale.
Thanks, this is what I was thinking, but I appreciate the detail.
It had not occurred to me that fuses are necessarily used near their limits.
It hadn’t occurred to me either before I was writing my response. 
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