Yes ... and no, Claude. 🙂
Yes, filters are described by their -3dB point - unless they happen to be Linkwitz-Riley filters ... in which Fc is their -6dB point.
I made an assumption that, given it was 24dB, the Pi filter was L-R ... that's probably an incorrect assumption.
Andy
Ah, L-R filters... you are a loudspeaker man! Good to know 🙂
My understanding is Mark's filters are in fact composed of 2 "simple" cascaded low pass filters, RLCs 2nd order (with very very low R) ones, hence the 4th order "in total" on one PCB,
Have a nice day Andy, and now that I found out that you are a filter sim pro, I might come back to you when I will tweak my Infinity LS filters (proper 4th order with 4 drivers, argh, these are giving me headache!)
Claude
My understanding is Mark's filters are in fact composed of 2 "simple" cascaded low pass filters, RLCs 2nd order (with very very low R) ones, hence the 4th order "in total" on one PCB,
Have a nice day Andy, and now that I found out that you are a filter sim pro, I might come back to you when I will tweak my Infinity LS filters (proper 4th order with 4 drivers, argh, these are giving me headache!)
Claude
@Mark Johnson
How can scale your filter for 4A or 5A?
What are the limit factors to only use it for 3A?
What's the purpose of R2 & R4 & how do you calculate?
TIA
Felipe
How can scale your filter for 4A or 5A?
What are the limit factors to only use it for 3A?
What's the purpose of R2 & R4 & how do you calculate?
TIA
Felipe
Will PO89ZP perform as intended with any low power smps?
Example:
www.cui.com/product/resource/psk-25w.pdf
25 watts, 24 vout, switching frequency 65kHz
Example:
www.cui.com/product/resource/psk-25w.pdf
25 watts, 24 vout, switching frequency 65kHz
For sure its is worth a try, why shouldn't it work?
I have over a dozen of these and tested them in many various cases (DACs, VFET amps, Class D amps, HP amps, Preamps solid and tubes etc.) with various loads and various SMPS and I have yet to find a unit where this filter did not enhence the sound WITHOUT ANY DOWNSIDE.
OK, in some cases if doing too much of it, read "daisy chaining too many filters", it can lead to a somewhat muffier sound than using only one... AGAIN IN SOME CASES. And on one single occasion, using the filter OUTSIDE of its intented ampere rating, did it lead a to mixed blessing, tones and mids and highs being better, bass dynamic impact worst, but again, that was over the intended operating range for a quick try (with the right safe components on the boards and still a constant average current draw well within specs, so don't try anything foolish on my behalf)!
In short, I find it works marvelously well in ALL cases without ANY downside (at least so far), as long as used with specs, eg despite using 5A rated parts not overdoing it with 3A max. Over its rated 3A (even on short Class D pulsed draws) you should really think "different filter".
All IME
Claude
I have over a dozen of these and tested them in many various cases (DACs, VFET amps, Class D amps, HP amps, Preamps solid and tubes etc.) with various loads and various SMPS and I have yet to find a unit where this filter did not enhence the sound WITHOUT ANY DOWNSIDE.
OK, in some cases if doing too much of it, read "daisy chaining too many filters", it can lead to a somewhat muffier sound than using only one... AGAIN IN SOME CASES. And on one single occasion, using the filter OUTSIDE of its intented ampere rating, did it lead a to mixed blessing, tones and mids and highs being better, bass dynamic impact worst, but again, that was over the intended operating range for a quick try (with the right safe components on the boards and still a constant average current draw well within specs, so don't try anything foolish on my behalf)!
In short, I find it works marvelously well in ALL cases without ANY downside (at least so far), as long as used with specs, eg despite using 5A rated parts not overdoing it with 3A max. Over its rated 3A (even on short Class D pulsed draws) you should really think "different filter".
All IME
Claude
I'm coming to this thread a bit late, and I am guessing, by now, these are all gone? I'd love one if there's one left.
Thanks,
David
I have some of these on order in red and I got some extras I can spare. If you are in the US, PM me and we can work out shipping for when they get in.
I have several packages of 10 PCBs that I am selling, see post #514 of this thread for details. I only sell complete packages (10 PCBs), not individual boards.
edit- when the Forum is set to 20 posts per page, post #514 appears on page 26 (math: Round_Up(514/20) = 26). So if the link above doesn't work for some reason, just scroll to the bottom of this page, click on the three dots "Go to Page", and type in 26. Easy.
edit- when the Forum is set to 20 posts per page, post #514 appears on page 26 (math: Round_Up(514/20) = 26). So if the link above doesn't work for some reason, just scroll to the bottom of this page, click on the three dots "Go to Page", and type in 26. Easy.
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I too would like to try building one but I guess it would have to be point to point as UK based.
A tad nervous about trying anything requiring the ability to actually understand a schematic rather than colour by numbers ;-)
A tad nervous about trying anything requiring the ability to actually understand a schematic rather than colour by numbers ;-)
Very easy, perfect first time project, very few components and little to do wrong or that can go wrong... you don't even have to 'understand' the calculation or schematic behind if you don't...
Get started mate, this is DIYAudio after all 🙂
Plus you won't regret it: you can use these filters on nearly every SMPS with benefits, as long as you stay within their ratings... great stuff, me says!
All IMO
Claude
Get started mate, this is DIYAudio after all 🙂
Plus you won't regret it: you can use these filters on nearly every SMPS with benefits, as long as you stay within their ratings... great stuff, me says!
All IMO
Claude
So, I’m going to give this ordering pcbs thing a try. Clearly Mark has generously posted the gerber files and has encouraged us try this ourselves. The noobie question I have is there a way from just looking at the gerber files to know how many layers are in the board? I have searched this thread and found that for this pcb it’s 2 layers but how would I know that without having found the info in the thread.
Me, having never dared to try p2p before, would approach it on the dry: print the schematic (large enough) and lay the parts onto the symbol, the trace the connection(s) either by pen on paper or with some thread or so. Then try to put that thing together (in a sensible manner)…
As was said before, this little preject is probably very well suited as a p2p-starter…
🙂
Mark, does this produce any meaningful heat? I'm thinking of putting one directly under an ACA mini and possibly encasing the whole thing.
One way to count the copper layers is to slurp the .zip archive file into a Gerber Viewer piece of software. I happen to like one that is completely free, you don't give them your email address, you don't even download the software . . . . it runs in your web browser. Just surf over to www dot pcbxprt dot com (don't use https) and presto. It prompts you for a .zip archive of Gerber files and tells you the names of the layers it finds. Here's a screen shot showing my browser connected to their website. I gave it the name of a zip file and it discovered two copper layers. Easy.
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