Ok great then, just wanted to be sure everything was normal. I think I will use the screws to make a spacer and let some more air cool the thing as long as it is on a wooden board.
Thank you!
Thank you!
The metal dividing plate on my smps also gets very hot to the touch when idle, seems to be normal.
Hi all,
Thanks for the cable advice!
Russell's example shows the mu of Fermi paramagnetism of aluminum. Those forces are orders of magnitude below those that result from the ferromagnetism of steel, and less than those arising from stainless steel. If the fellow had used a steel plate he would have caused a violent collision, not paramagnetic repulsion. (Yeah, I did have to look it up again, I'm a forgetful old technician and fledgling physics student.) Induced EMF happens with all conductors, but hysteresis is a different animal.
Does hysteresis of a bent steel chassis cause enough EMF in a circuit to measurably affect its performance? Well, of course it depends on the currents, distances, type of steel, and sensitivity of the circuit. As in so many challenges in life, I rely upon the kindness of... better designers. A few years ago I was at an AES convention grilling poor Grant Carpenter (Gordon Instruments, gordonaudio.com) about mic amplification, when he was approached by another, more famous maker of fine pro gear. He and Grant discussed a new converter the fellow was planning, and Grant urged him to replace the steel portion of the other makers' chassis, because the hysteresis was measurable and had ugly (albeit very small) effects on the signal. Aluminum's tradeoff of near-zero EMF shielding for very good RF shielding is best addressed by good layout and grounding. Anyway, I just say to do it because somebody else said so.
Thanks for the cable advice!
Russell's example shows the mu of Fermi paramagnetism of aluminum. Those forces are orders of magnitude below those that result from the ferromagnetism of steel, and less than those arising from stainless steel. If the fellow had used a steel plate he would have caused a violent collision, not paramagnetic repulsion. (Yeah, I did have to look it up again, I'm a forgetful old technician and fledgling physics student.) Induced EMF happens with all conductors, but hysteresis is a different animal.
Does hysteresis of a bent steel chassis cause enough EMF in a circuit to measurably affect its performance? Well, of course it depends on the currents, distances, type of steel, and sensitivity of the circuit. As in so many challenges in life, I rely upon the kindness of... better designers. A few years ago I was at an AES convention grilling poor Grant Carpenter (Gordon Instruments, gordonaudio.com) about mic amplification, when he was approached by another, more famous maker of fine pro gear. He and Grant discussed a new converter the fellow was planning, and Grant urged him to replace the steel portion of the other makers' chassis, because the hysteresis was measurable and had ugly (albeit very small) effects on the signal. Aluminum's tradeoff of near-zero EMF shielding for very good RF shielding is best addressed by good layout and grounding. Anyway, I just say to do it because somebody else said so.
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Me either. $20 oxygen free copper speaker wire and balanced cables with good build quality and low price totally suffice. This is one area not to obsess over or spend too much.
EDIT: Sorry Russell, you were right, it was an eddy current, where a moving B field induces current in the conductor, which creates an opposing B field that creates the repulsive force seen. I sure liked the Fermi paramagnetic angle though...it's real, but less strong than the force created from the induced eddy current. The EMF from those eddy currents still is far less than that from interaction of ferrous casing and nearby conducting paths, but you had the right phenomenon. Now you know why I've taken 35 years to complete a handful of physics courses. I even did the magnet-falling-through-copper-pipe experiment just last summer. Sigh.
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I remember a Discovery program (maybe about the Trust SSC or another land speed record car) that uses brakes that work on this principle to slow down at extreme speeds. Also the high speed ICE train in europe uses this principle: Eddy current brake - Wikipedia, the free encyclopedia
But I am getting way off topic here 😛
i bought a few of these
Aluminium Chassis for audio DIY (pre amp, headphone amp, DAC, etc.) | eBay a month ago, and finally got them, the height is just perfect, have maybe 2mm of clearance from the top heatsink on the smps600 with the spacers still attached to the bottom of the board. Just enough space inside for everything i need.
Aluminium Chassis for audio DIY (pre amp, headphone amp, DAC, etc.) | eBay a month ago, and finally got them, the height is just perfect, have maybe 2mm of clearance from the top heatsink on the smps600 with the spacers still attached to the bottom of the board. Just enough space inside for everything i need.
anodizing adds resistive barrier
I have a big concern about anodized aluminum enclosures. I used to measure several hundred ohms across some big areas. If masking (where special tapes prevent exposure to anodizing) is done well, you often can't see where it's been used after assembly. And if the anodizing is clear, it's really really hard. I just posted to ask if cOz was masking parts of his ncore cases. For adjoining plates, screws and the huge anodized contact area should eliminate most of the problem. I even worry that Audioquest's XLR connectors (look at their male shells at Cosmic Series) appear to be anodized on surfaces that need to have very low contact resistance. Even Neutrik XLRs look bad on this, I'll need to look for some black-anodized ones that I used to have in large numbers.
AHA! This from Neutrik: "The contact resistance of chromium plated (black chrome) shells is slightly higher than the resistance of nickel-plated shells. That’s usually no problem for all audio transmissions. Regarding EMI at HF transmissions we recommend to use nickel plated cable connectors in combination with chassis connectors with EMI optimized ground contacts." from:
Do black chrome shells have grounding disadvantages? - Neutrik
Geez, I'd never heard of black chrome, had you? Cool!
Of course nearly all non-rare-earth metals begin to surface oxidize even before they solidify in their creation, but the resulting oxide layers still conduct better than anodized surfaces. Good old tin plating is great in this regard, gold better, and I have no clue how well rhodium works. I was also surprised to learn that tarnished silver has almost no increase in resistance compared to the shiny stuff.
Anyway I just wanted to bring this to DIYers' attention.
I have a big concern about anodized aluminum enclosures. I used to measure several hundred ohms across some big areas. If masking (where special tapes prevent exposure to anodizing) is done well, you often can't see where it's been used after assembly. And if the anodizing is clear, it's really really hard. I just posted to ask if cOz was masking parts of his ncore cases. For adjoining plates, screws and the huge anodized contact area should eliminate most of the problem. I even worry that Audioquest's XLR connectors (look at their male shells at Cosmic Series) appear to be anodized on surfaces that need to have very low contact resistance. Even Neutrik XLRs look bad on this, I'll need to look for some black-anodized ones that I used to have in large numbers.
AHA! This from Neutrik: "The contact resistance of chromium plated (black chrome) shells is slightly higher than the resistance of nickel-plated shells. That’s usually no problem for all audio transmissions. Regarding EMI at HF transmissions we recommend to use nickel plated cable connectors in combination with chassis connectors with EMI optimized ground contacts." from:
Do black chrome shells have grounding disadvantages? - Neutrik
Geez, I'd never heard of black chrome, had you? Cool!
Of course nearly all non-rare-earth metals begin to surface oxidize even before they solidify in their creation, but the resulting oxide layers still conduct better than anodized surfaces. Good old tin plating is great in this regard, gold better, and I have no clue how well rhodium works. I was also surprised to learn that tarnished silver has almost no increase in resistance compared to the shiny stuff.
Anyway I just wanted to bring this to DIYers' attention.
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Don't forget that you'll need some 0.5mm or thicker insulation material with that low a clearance, to stay on the safe side of DIY 😉
Yes, and that electrical insulator is usually a good thermal insulator, so consider the loss of that heatsinking...
The only thing that gets close is the heatsink on top of the smps600, i'll probably put some kapton tape on the chasis part that gets closest to the heatsink. there is full clearance on the bottom, the original spacers are attached.
http://i150.photobucket.com/albums/s87/ufokillerz/IMG_1033copy.jpg
This is how it looks in the ebay case, some space to play around with, height is perfect as mentioned.
cant get the image to show properly, so click on link!
This is how it looks in the ebay case, some space to play around with, height is perfect as mentioned.
cant get the image to show properly, so click on link!
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Hi Ufokillerz, I would recommend to turn the SPMS600 180 degrees. This way you avoid routing of the NCore400 power supply cable across the SPMS600 or crossing of the mains power cable..
Thats great I have the same case which I've prepped and fitted the XLR connector - Hypex delivery should be tomorrow - AJ
Thanks i will keep that in mind, new to diy, and all, but just wanted to put them in for some pictures.
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