Thanks for bringing to my attention that there's a fuse in the tuner, which I've overlooked all these years. Now I have something to look into..
All the best,
Nonoise
Fuse Direction for Pass Labs Amp and Preamp
I am going to re fuse my Pass X250.8 and XP-32 with Synergistic Research purple fuses in a couple of days. I was hoping to get advice on a rule of thumb for direction of the fuses. My instinct tells me to start by installing the fuse by the direction of the lettering on the fuses. 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?
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"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?" If you leave the "US" and "WE" out of the post you might be close. I’ve worked around a lot of different engineers. Every sound engineer was working on sound walls and every EE was working on CANN Buss/OBD2 equipment. They normally were working out a way to add another computer to the mix. Sound is as subjective as anything on earth and very prone to BIAS. I understand that. The difference with people that are PAID to listen vs people that PAY to listen is pretty simple. Music SQ vs a strange noise in the engine compartment is just a little different skill set. It took many mechanics decades of learning to hear and then feel a potential issue. I bow to only a few when it comes to better hearing and with better skills. I suggest many people and the way they learn to listen is the greater issue. It’s only a problem if "WE" can’t learn to change and learn a BETTER way to listen.
With that said, what can I say about this: "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." OK you got me, you win, 10ga OFC spools cable is just as good as SRs speaker cabling. I suppose you hooked it all up and did a side by side on two identical systems too? GIVE ME A BREAK, you did NOT. Second if you can’t hear the difference in a UP-OCC/teflon weave from your 10ga OFC spool wire. QUIT trying your hearing is SHOT. Stick with the old scope. The thing about any mechanic worth his salt is to question his/herself abilities before others do.. I’m not the one that couldn’t hear the difference. I suggest a little training is in order. Start with the easier ones first. 2-4ohm 90-92% efficient speakers. The more efficient the speaker, the easier it is to learn about cables, not WIRE. It’s not hard to understand that a mechanic is usually a pretty skilled engineer with dirt under his fingernails. Certainly had to go to school a LOT longer. I still attend 3-6 classes per year, 40 years after my Master Certs (7 years). I taught hydraulics with OHM for over 20 years. We both worked with James Bongiorno and a few of his crew. He would chew anyone out for not paying attention to single wire or cabling. 35 years ago? He did some amp board work for a series of cranes we has issues with in the heat.. Carver use to teach a winding class for 2nd year guys. Cheapest guy I ever new, but not with other people’s money.. :-) Can’t hear a difference? "just for fun" try to learn a new skill set. My best to you all. PS Ralph, I think you're one of the finest contributors to the forums with a wealth of knowledge and as always a gentleman all the way.. We've met in passing many years ago..
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People risk their lives on electrical theory, just as they do the theory of flight. I suspect you might mean 'hypothesis' rather than theory.
My hearing certainly isn't what it was, but I hear differences easily enough. However my employees' hearing is much better and they couldn't hear any significant difference either; neither could the guy that lent us the cables! That might be different if the speakers were 4 Ohms but they are 16. That makes a big difference.
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Perhaps I should have said, "That's why there have been so many theories and theorems." ie: https://en.wikipedia.org/wiki/History_of_electromagnetic_theory Many folks are still wrestling with the High School level understanding, of shoving electrons around, in a conductor. Such that do, are still stuck with theories proposed in the 1800s. To help you understand the difference between a hypothesis and a theory, a copy/paste from another post: The goal of the Scientific Method: to answer WHY observed phenomena occur. The steps of the scientific method include: 1) asking a QUESTION about something you observe. 2) doing background research to learn what is already known about the topic. 3) constructing a, "hypothesis". 4) experimenting or testing the hypothesis. 5) OBSERVING the results 6)ANALYZING the data from the experiment and drawing CONCLUSIONS*. ttps://www.indeed.com/career-advice/career-development/scientific-method-steps When one of the Sciences runs into a phenomena, for which it hasn't yet figured out a method of testing (experimenting) the HYPOTHESIS, or: can't yet understand (analyze) whatever data might been found during experimentation, there can be no categorical, answer* to the question, "WHY?", and a, "THEORY" is proposed. *Without definite conclusions, there can be no categorical answers.
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I thank everyone for a little spring in your step.. I thought I was going to fall into a coma these last couple of months.. :-) LOL From Kimber about Kimber KAPs: "All values of Kimber Kap have a red lead at one end. The red lead should go towards the +DC voltage, or away from the –DC voltage. In coupling (DC Blocking) applications the red lead is the signal output end (it will be the same as the +side of an electrolytic capacitor in this position). In a loudspeaker crossover, the red lead should go towards the drive unit + terminal. The capacitors can be used safely in either direction but the marking indicates which way will minimise hum pickup." This can be figured out with 99% of NP caps. Kimber just realizes some measurements aren’t accounted for in the OLDER "this is how it works" crowd. Does it make a difference? I repeat from KIMBER. "indicates which way will minimize hum pickup.". It’s showing where the outside of the film wrap is. Kimber seems to think there is a direction in a NON directional cap. :-) I just happen to agree with the manufacture too. Stealth Caps work VERY well in the right direction. I just installed a set in the Cary and added Deulund .01 bypass (in the right direction).. The umbilical cable was replaced with Kimber and I rewired both preamp and power supply in the right direction. It was wired in both direction from the factory. It’s not now. How does it sound?. Like it need 200 hours to break in. BTW I’m running my monitors at 12 ohms (static). 400Gan for the summer. What a nice sounding amp. |
When I bought the Duelund CAST-PIOs for my Carys; I asked which lead was the outer foil. "Doesn't matter!", they said. I've had a habit of testing everything for noise/best performance, before committing to an install, for decades. Just an FYI (If one doesn't own an O-scope): Just rig an RCA lead with gator clips and plug it into one of an old receiver/integrated's PHONO inputs, with the volume all the way down. With a speaker attached, of course. Hook up the cap's leads and LIGHTLY grip (especially films) the sides of the cap, while slowly raising the volume. Keep it real low! Change the component's input selector, and switch the cap's leads (don't move the volume). Switch the selector back to PHONO. One direction (when the outer foil's lead is connected to the Positive Phono lead) will result in much more hum. For the lowest noise in a signal circuit; connect the outer foil to the lower impedance (signal source). OH, and: It REALLY DID matter! More info: https://www.aikenamps.com/index.php/where-to-connect-the-outside-foil-on-capacitors |
I tested a pile of SR fuses years ago and noted the results here. They’re dangerous (rated wrong at times so they blow, leading to suggestions that you should use a higher rating than the gear called for...wow) and useless nonsense. Some have claimed their system sounds "out of phase" when the proper fuse direction is wrong or bloviated about how astonishingly fabulous the fuses "sound." Hey, it’s a FUSE... Why haven’t they caught on among manufacturers or most of everybody else? Hmmm...I recently bought a Pass XA25 and called Pass Labs to ask some dumb question and wound up having a great conversation with ’em, but really...I suggest you call Pass and ask about fuses...let us know what they say... please... |
I don't think a single person HERE is implying Atmasphere or the product he manufactures is anything but "Top of Line", "Best in His Field". Please understand other professionals do exist outside the audiophile community that also encompass most of the disciplines for building stereo related gear, including the furniture audiophiles use. Audiophiles may be a select community, but they have reached way beyond a lot of the older facts that use to be accepted as gospel. Cable is cable. Fuses are fuses. OAK is the only speaker finish. Class Ds suck. Why are you still using tubes? Concrete everything to the floor. Speaker spikes work. and the biggest of all, Come to AG and get a blast from the past. Everyone has peers. I don't want to equate emotional attachment to a great person in leu of the fact, other people build crazy good amps TOO. Some not for a living but for pure pleasure and because they can take the time a lot of great production manufactures, CAN'T. If they did it would cost me or you 60K plus ++++. I can't afford Ralphs Best and a 2+ year wait. At least his company offers it. Most don't. I like Dodd's mods. Try to find his work. Samra's Mac builds, Herron's, there is a few great builders and more than one size fits all. I like things MY way, when I pay. From OHM mouth to this screen verbatim. I'm on line with him in real time face to face. "The Finnish people have BIG rabbits" "They eat a lot of duck eggs too." "I wonder if they quarantine rabbits? I bet they do. Get a bill for 20K behind a rabbit." "The Finnish people have LOTS of tubes too. They could hold out until the second coming. The Finns are hoarders, Thank God. They actually laugh about Putin's Russia. They have a lot better equipment too. 7-800 miles of borders with that Bully for years. It's no big thing to them. They HATE Putin's puppets. Seagal is the NEW word for $hit in Finland. Get the Seagal off your BOOT" It's all the time I have, back to work. SLOW day. |
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You might be interested to know that my LP mastering lathe, which was originally built about 1949, sat atop a custom table that featured adjustable points for feet. So the idea of the points that so many audiophiles use has been around a very long time. You might also find this interesting: You can look at any amplifier as having a perfect amplifying element with a distortion element (nonlinearity) in series with the signal. Put another way the differences you hear in amplifiers is simply the distortion signature. Because of this, if you have the distortion signature of a tube amp and were somehow able to put it in a solid state amp, the solid state amp would sound like a tube amp. We discovered how true that really is when we were developing our class D amplifier, in which the non-linearities tend to generate lower ordered harmonics rather than higher orders, so it has the smoothness and lack of harshness you expect from a really good tube amplifier although a bit more transparent. It is the distortion signature of tubes which has kept them in business so long after being declared ’obsolete’ in the early 1960s. But now you can get the same distortion signature in a solid state amp (although maybe 2 orders of magnitude lower, allowing for greater transparency) with the same liquid mids and highs. We’ve encountered cheap fuses that are not worth using. A a good quality fuse like Bussman or Littlefuse is hard to beat: if you are trying to use a boutique fuse, the former brands should be your ’control group’. In 1990 when designing our MA-2 we recognized that fuses were a problem, so we use a different kind known as an FNM. https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/fuses/bussmann-series-supplemental-fuses/supplemental-fuses-midget/bus-ele-ds-2028-fnm.pdf This is a physically larger fuse employing dual elements and a larger fuse holder that exerts much more pressure on the fuse contacts, which are also much larger. They and their fuse holders easily outperform any boutique fuse made today. We did this and also used dual power cords on each chassis to minimize the internal and external effects of AC power wiring. So please take it that when I say the direction of a fuse isn’t a thing, its with the awareness of fuse effects going back over 30 years, long before there were any boutique fuses.
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Would it be fair to say (or infer) that some of these boutique fuses are somewhere along the arc between a bog standard fuse and those FNM fuses? That they are definitely a step up but still nowhere near a FNM fuse? That could be why we hear a difference: they're simply a better made fuse, kinda like what you got with the FNMs. Just saying.. All the best, |
For your control group let me recommend these. https://www.littelfuse.com/products/fuses/cartridge-fuses/5x20mm-fuses/285/285001.aspx And yes, places like Mouser sell them individually or in small quantities. |
Some of the boutique fuses we've seen are inferior and some are OK so there's not a good answer to this question. We've seen some that employ a Teflon tube to damp the motion of the fast blow element; this type of fuse might not blow correctly since the metal can go to liquid and still be supported by the tubing- at that point would eventually become a plasma. I'd stay away from any fuses constructed in this manner. We've seen some that don't hold the current they are rated for and some that won't blow until you're a bit over spec! None of these are good situations. Having an equipment failure on this account wouldn't be a good thing so when people ask me about this on the phone I let them know what we've seen. |
Roger Modjeski (Music Reference, RAM Tubes) had a thread dedicated to fuses in his AudioCircle Forum. In it Modjeski disclosed what he had discovered during his investigation into some of the audiophile fuses, and how they compared to the Littlefuses he supplied in his amplifiers. One of the biggest boutique fuse makers went to work on the AudioCircle honchos, and Modjeski's Forum was closed. The thread is still available for reading, for those who are interested enough to search for it. |
