Welcome aboard! That diagram applies to any enclosure made of metal (or any material that conducts electricity), so your choices should be OK
I believe the wood pieces are the sides of the chassis, nothing would be attached to the wood. I have been reading to try and gain a general electronics understanding so I wont kill myself or burn down the house. it is my understanding that copper & aluminum provide electrostatic shielding whereas steel and Mu Metal provide both electrostatic & magnetic shielding.
Roughly true. The question is are you going to need it? A lot of people have been running their nCores on a tabletop without an enclosure and have had no issues with interference. Will you have other electronics stacked close to your amp(s)?
Aluminium will act as a magnetic shield for AC magnetic currents. It will do nothing to DC magnetic currents. A ferrite will reduce the EMI from leaking via the speaker cable. Some equipment is sensitive to EMI at certain frequencies, and the EMI from a class D amp is both pretty broad band and quite load dependent.
For shielding to be effective it's got to be really close to the source. Chassis make lousy shields because anything you might be trying to shield against has already coupled into the wiring inside the chassis. If you want to use the chassis as a shield you need to have feed-through filters on every piece of wire. But that's something you'd only do if there was a problem to begin with... The NC400 is pretty quiet so I'd just pick the chassis on aesthetical grounds.
@juhleren if I follow your reasoning you're proposing that placing a large inductance across the speaker somehow affects the signal in a good way? Before discounting the resistor hypothesis it's worth an experiment to add a small resistance in series with the amp and hear what it does.
@juhleren if I follow your reasoning you're proposing that placing a large inductance across the speaker somehow affects the signal in a good way? Before discounting the resistor hypothesis it's worth an experiment to add a small resistance in series with the amp and hear what it does.
DC magnetic currents? And in what way will a static magnetic field influence *anything* apart from a compass needle? (OK, it might pre-bias some transformers, but is that really a factor to consider?)
A ferrite on a speaker cable is a really bad idea.
Have you measured the EMI from a nCore?
- Affecting the signal, yes that is what I suggest (Or rather the conditions under which the signal is transmitted / the way the O/P stage couples to the speaker).
- In a good way, that depends on what one is trying to achieve.
Ideally, we all probably agree that the more direct the O/P can drive the speakers coils, the better.
I haven´t tried adding a resistor to a ncore, but I have on UCD´s and several other amps. It is based on those experiences that I believe the "resistor hypothesis" doesn´t quite get the whole picture as to mimic what an O/P trafo does.
Interestingly, I found that ICEPOWER and UCD that both have very low O/P impedance suffered most from adding a 0,22R. They sounded very wimpy and lost much detail and "color" in tone.
BTW, regarding the smps600: does it have chokes on only aux supplies/driver supply only, and/or on the O/P stage supplies?
cheers,
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No, that is why I think stainless steel, aluminium, copper and so on works just as well as iron, steel etc.
Why do you think so?
No
a.wayne, we are all buying the NC400 (€325) and the SMPS600 (€180) from the only current source, the Hypex web shop.
If you search "aluminum magnet" on YouTube, a number of videos appear showing how aluminum interacts with a magnetic field. Here are a few:
Awesome Magnet Tricks - Eddy Currents - YouTube
Magnet Brakes its own fall - YouTube
I can see from these videos why some manufacturers use wood or plastic for their chassis materials.
Awesome Magnet Tricks - Eddy Currents - YouTube
Magnet Brakes its own fall - YouTube
I can see from these videos why some manufacturers use wood or plastic for their chassis materials.
And copper's evidently worse!
Magnetic Levitation over copper - YouTube
Edit: Lenz's Law, evidently.
http://www.wimp.com/copperpipe/
Magnetic Levitation over copper - YouTube
Edit: Lenz's Law, evidently.
http://www.wimp.com/copperpipe/
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@Juhleren, the chokes are in the high voltage lines. The low voltage lines use ordinary SMD beads. With regards to inductors in parallel, the only way that can make a load look more resistive is when you're driving only one frequency and the load is capacitive at that frequency. There is no generic "impedance improvement circuit" that you can slap across any speaker in the hope of making the whole thing less reactive. I think some SPICEing around may improve your intuitive feel for this problem.
@Julf, Ferrite beads on speaker lines are only a bad idea when you put one on each wire, because these things are hugely non-linear in the presence of current. If you put one on a neatly twisted pair it doesn't hurt because the audio currents in both wires cancel.
(That is not to say that the NC400 needs that treatment though)
@Julf, Ferrite beads on speaker lines are only a bad idea when you put one on each wire, because these things are hugely non-linear in the presence of current. If you put one on a neatly twisted pair it doesn't hurt because the audio currents in both wires cancel.
(That is not to say that the NC400 needs that treatment though)
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