The custom referred to the value, precisely 1/3uF. They are used in some of the tuning circuits for the notch, and the 1/3uF value rationalizes range switching for example.
Jan
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That is kina interesting. Vicnic mention that FPK (foil) is better than MKP (metalized) and I am, according to Bruce, suppose to use foil cap's rather than metalized caps. I am actually planing to replace all the electrolytic in the NC400 with FPK cap's. Looking at Victor's data, I kinda wonder if one should consider replacing the C0G as well ... this is confusing to me... lol
Low-distortion Audio-range Oscillator
Which is absolutely why I said you need to test these differences in your specific application. At least when -140 dB below I believe 2 Vrms is the goal. It's ironic you quote me and then completely missed the whole point I made.
Flipping capacitors on a NC400 seems like a fool's errand, however.
Flipping capacitors on a NC400 seems like a fool's errand, however.
Those electrolytics in the NC400 are supply decoupling, not signal coupling. Comp[eltely different application. Those electrolytics need some loss to work their job well.
Jan
Its not on the original board, its custom made boards for a custom made NAD M22 special edition. But that's for another day
I am glad to see some FPK data out there, my gut feeling about Wima was right. Wima's DC-Link range should also be splendid to use in SMPS.
Stop calling that a Nad M22 special. It's silly.
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Not at all. Those caps are specced as +/10% at the very best, often +50%/-10%. What's a small change with temp doing?
Here we want just 'a bunch' of capacitance to act as a charge reservoir. It's the designers' decision how much, as the benefits and requirements are conflicting. Taking into account the amp PSRR, don't use too much because that causes more EMI spray of the sharp charging pulses; not too little because it can give residual hum.
Dielectric absorbtion? Who cares in a power supply?? So you lose a few milliwatts?? Actually, some lossy elcaps are the best, because that loss absorbs some of the ripple, turning it into a bit of heat, instead of turning all of it into ground currents.
Its all about the application.
Jan
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Joined 2009
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. You misunderstood
. Its not that I call the M22 special - full stop. I am simply referring to an M22 project that I am working on which I call NAD M22 Special Edition. Take two M22's, use one chassi for the amp modules and one chassi for the SMPS, throw better components at it and you have a special edition.
I see.. that kinda makes sense. I wish it wasn't so. What if all of the PSU and decoupling caps where PP-foil/film caps and you use shielding, the PSU in its own case, only delivering clean DC to the amplifier modules which is placed in its own chassi. Would that take care of the main ripple, RFI and EMI ?
No I was just saying that if you think that you should put the same requirements to a power supply cap as to a signal coupling cap, that's wrong. Choose what is best for the application. Film caps in power supplies can lead to worse results just because they are lossless.
Jan
. Thanks for clarifying
. There must be better ways to clean the signal. Ripple is stability issues, is it not?Isn't the rule that the more accurate components are the less ripple there will be, and if you use shielding such as separate PSU and amp/electronics chassi, the less RFI and EMI there will be ?
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