I know this is an older thread but I had a similar problem and found the answer here, I hope anyone else who comes across this might be helped as well.
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I know this is an older thread but I had a similar problem and found the answer here, I hope anyone else who comes across this might be helped as well. |
Circuit breakers are slightly inductive and usually have a higher internal resistance than the equivalent fast-blow fuse. If in doubt, do a search for data sheets, e.g. a Bussman fuse as compared to a circuit breaker. For example, a 500 mA circuit breaker has ten times the internal resistance of a 500 mA fuse. IMHO do not use them for audio. |
You know, Lacee, I'm wondering if part of the reason the Antique Sound Lab Hurricanes were so prone to blow resistors could be a function of the original fuses, which were, of course, inexpensive. I don't know, just speculating. Back to the HiFi Supremes. I am continuing to be astonished at how much "cleaner" the sound is with the Supreme in it (only one amp has it in it: the other is on its way). I have Tube Traps (around 40 of 'em) and it is SO easy, now that the Supreme cleans up any "fuzziness" or "halo"-effect around instruments, to tell when the sound is an improvement or a detriment (meaning: you can turn a tube trap 1/16" and kill the transient or you can, equally, improve the clarity of the transient). Also, the ambience AROUND the instruments is so much more easily discerned. I've only had the Supreme in one amp since Friday (December 30th). A friend of mine, Dave, who loves Scheherazade, listened last night and was puzzled that the highs seemed diminished, but that the midrange was gorgeous. We later traveled to another city for New Years Eve, came back today, and I went into my room and listened again. Movement 3 has some triangles around 4:45 that, prior to today, were somewhat muted. When I listened a little while ago, they were much more audible, and no changes were made in the interim (including moving a Tube Trap, which could also make the highs more audible if turned, as I said, as little as 1/16"). I just sat down and listened and the transient AND the harmonics were unambiguously clearer. I can hardly wait for another 72 hours to pass. I fear to see the electric bill, though... |
I have not used a circuit breaker (I'd probably electrocute myself), but I CAN suggest HiFi Tuning fuses (I got my first ones 3 days ago, and MAN, did the purify the sound ("purify" in this sense means ridding the sound of grit and significant amounts of grain, lowers the noise floor (!) and improvements imaging, soundstaging and precision of image improvement. And those are just the audiophile things! Musically, a flute sounds woodier and the cello and double bass are particularly noticeably better in pitch and weight. And lets not forget the microdynamic improvement (part of the lower noise floor, which lets subtler information be heard). Try them out first. Circuit breaker later! |
Magfan, I'm familiar with the dual magnetos required for piston powered planes. Double needed to stay flying if the other fails. I'm also familiar with different ram air turbines (RAT) needed for a lot of airplanes, for hydraulic and electrical power. I don't see how any of this will help the OP though. |
Ryanvt, this is all new to me. I haven't heard of any breakers for audiophile gear like your speaking of. With the breakers I've seen, I don't see how they can make a more solid connection than a fuse whose connection is solid inside. No breaks in a fuse that can make noise. I wouldn't know where to begin on recommended a breaker to replace the miniature fuse in an amp, especially one that can maintain a more solid connection. In the '60s or '70s, I remember companies started using breakers on TV sets. They called a lot of them "reset" buttons. These were mass production, and I imagine they tried to save every penny making them. Then about the time they went all solid state, they went back to fuses for some reason. Even the new D'Agostino amp appears to have a standard fuse on its case back. Link [http://www.dagostinoinc.com/] I would like to provide info if I could. |
Thanks for the very informative input so far. It seems the main stream audio designers go with fuses (cost savings and/or ease of export to the myriad voltages and resulting current ratings?) while a couple of designers and mod shops do promote the sonic advantages of CBs. I am still weighing what CB would be an "or equal" to a 5 Amp slow blow fuse, and if I have space in the fairly large enclosure. I did make a DH 120 kit amp in the 80's - albeit with better eyesight. |
And don't forget that their is another class of fuse which is VERY fast acting and used to protect delicate semiconductors in certain applications. Personally, I'll stick with fuses. Inexpensive, reliable and need no special attention. Breakers make perfect sense in some applications. A breaker can be used to shut off an entire circuit....use it as a switch, maybe. Private planes don't generally need electricity to fly but DO use plenty of power for avionics. The spark plugs are fired by Magnetos, maybe still. I've seen commercial with an extendible air powered genset to provide minimal power to controls in the event of a catastrophic power fail. A similar unit is STC'd for several planes as an add-on. (STC=supplimental type certificate) |
The OP of the thread amps have a setup similar to what I'm familiar with. The slow-blow fuse is on the back, for easy user replacement if needed. This one will handle the turn on inrush needed, especially more so to charge the power supply caps. The fuses that help protect the semiconductors inside the amp, has the fast-blo fuses inside. Due to the 0.100 second resolution in our testing equipment, we were unable accurately to compare the response times of the devices to a massive over-current condition such as would result from, say, a short circuit. That is, when we applied 10 times the rated current, both devices reacted within 0.100 seconds. This time suggests that either device would be adequate in applications where the goal is to protect circuit power wiring as opposed to protecting the circuit itself. What this person has written even seems to match with the amps protection, to a degree. In the article, he is mainly concerned with a fire (wire overload) in the plane from the way I read it. If something fails on the inside of one the aircraft's components, hopefully he has a second (radio for example) for backup, and can make it safely to an airport. Link for the OP of the thread amps.[http://www.classeaudio.com/downloads/pdfs/archived%20manuals/CAM-200_Owners_Manual_v1_0.pdf] |
JUST like MOV devices in surge protectors, Circuit Breakers 'age' poorly and change with repeated cycling. Other articles testing really HUGE breakers say calibration is needed after a trip. Read the conclusions of the article I cited. Time lag may not be an issue. Besides, if it were, you'd still have possible replacement for Slo-Blo on the table. and though, like the rest of us HIFi is right and wrong at different times and to different degrees, the 'How often does the fuses in your amp fail?' remark is spot on. Are breakers a solution in search of a problem? Since I've NEVER blown a fuse in my panels, I'll eventually do some wiring changes to both simplifiy and eliminate the fuse. Problem solved. |
The test that was provided by Magfan was for an aircraft. He said the company was saving money. I don't know anything about that guys light aircraft. I think Cessna used breakers the same year his plane was built. It can get busy in a plane. So if a fuse blows, you need to locate the proper one, make sure you have the proper fuse in hand, and replace it. If your flying a little single engine like this guy was, you may be alone, and doing this in bad weather, in a busy pattern, plus an endless list would be plenty of reasons to want breakers in an aircraft. Just for what it's worth, breakers go bad too. I remember a few years back, I was with a friend who was flying me to a non-controlled airport that was doing maintained work. They had no runway lights due to the maintenance. When he turned his landing lights on, nothing. We had to turn around and go home. The breaker failed in it. Also, last year I had to replace the breaker for our home HVAC, as it was humming loud (a sign of overload, or tired), and tripping off at times. The replacement does have a slight hum, just like the original did since it was new. This is common for breakers. If anyone was in a breaker room for a large building, they no how noisy that can get, even causing the need for talking loud in some of them. So how much noise do these add to the line? I wonder if anyone measured it? His test (aircraft guy) wasn't conclusive for the fuse test, due to 100ms limitations on the test equipment. How often does the fuses in your amp fail? I can't remember the last time I've needed to changed one. With everything said, I have no desire to risk changing over to breakers. I don't see any info that says a breaker can react to the fast speed, that can save something from short peaks that can occur in our equipment, that a fuse that we forget is there, can also save a costly repair. No tests for added noise, that may result from a breakers pressure contact. Too many unknown risks, and possible added noise. If your blowing fuses on a regular basis, get it fixed. So, I'll pass. Why add a problem is what I think. |
