Well, I have been searching the forum before posting my questions without finding answers. Could you give some links to interesting posts? Thanks!🙂
Regarding the mains filtering, there is filtering built in and I have been advised an additional filter is unnecessary however feedback from someone I know who tried adding a Schaffner filter to their UCD amps was that there was an improvement so for the sake of very little cost I am likely to include one.
I was going to use one too, but then I bumped into this (old) post from Bruno, where he recommends against using such commercial filters.
I'll probably rely solely on the filtering of the SMPS.
Best practices / pending questions according to what I gathered:
- do not use Shaffner or any other Y filter
- do install some EMI screening between SMPS and amp modules (many DIYers look to have set up some according to their pictures)
- do use a 255Ohms@100MHz ferrite clamps (see http://www.diyaudio.com/forums/class-d/42146-ucd400-q-29.html#post512556) around SMPS to amp cabling (close to the amp module), around speakers cables (really??), around mains to SMPS
- do twist cables but no idea if any better shielding could improve
- is a speakers protection circuit useful considering all built-on protection routines of the nCore amp module to avoid "plops" in speakers at switch on?
- Some of you seem to use a switch on the mains between IEC plug and SMPS, some use the nAmpOn Pin J9:3 and the SMPS even have its own pin for stand-by (Pin J1:1). Advantages / drawbacks of possible power-on layouts?
Thanks for that I shall give it some thought. I'll probably revert to my filter-less design as I still have the option of mounting one externally.
I've never investigated whether this can be the case or not, but an EE once told me that sometimes mains filters in series can resonate with disastrous effects.
I wonder if you can squeeze the molex connector through the ferrite ring. Disconnecting the molex is easy but re-connecting it is a different story without the right tools. It is easier to use a ferrite clamp for this.
What about the impedance's if the rings/clamps. Should it be 255Ohms@100MHz? What makes this so special? Can anyone explain this?
I will be trying a miniDSP upstream of my NCores which is purported to have a large amount of out of audio band noise. I was wondering if I should add a filter to the nCore input to avoid any issues. Thanks.
"...do install some EMI screening between SMPS and amp modules..."
I could be wrong, but I thought Bruno said that there was no advantage to using any screening.
I could be wrong, but I thought Bruno said that there was no advantage to using any screening.
Sorry, I just assumed that using the Hypex SMPS was a given. I wasn't thinking about other SMPS options.
I'm sure this is a silly question, but where does one order the Ncore? Is there a signup? Pricing?
Is it okay when connecting the SMPS600 to the NCore modules to run the connecting cable either across the top of the SMPS600 or underneath the SMPS600?
Based on the way I want to orient the SMPS600 to the NCore, it will be easier if I can run the cable across or underneath the SMPS600.
Based on the way I want to orient the SMPS600 to the NCore, it will be easier if I can run the cable across or underneath the SMPS600.
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