PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc

They should be more than happy as this is a realy useful and nice little project - get it started, folks!

For those interested in real life figures, with a low skilled DIYer (me!), my modules measures both indenticaly:

1) Mass, from input to output, 0,13Ohm (includes cables, solder joints, board, connectors... and also the cables from the multimeter, which were measured separately at 0,08R)... so I assume 0,05R for the "device alone" from "mass in" to "mass out"

2) +, from input to output, multimeter showed 0,23Ohm... so I assume 0,15R for the "device alone"

These values seem to me to be in line with what Mark predicted and were achived with cheap cables and connectors lying around... these are negligeable losses at that kind of amperage.

Have yet to plug an oscilloscope or even better... to listen to it.

Have fun and don't miss on this one: it could well be a very handy solution based on the oscilloscope measurements Konst did on his unit post #40, quite revealing...

Claude
 
The listening is what will be most interesting. I have them on my Pi/Digione, and it seems to make a small difference. I have a KorgB1 (balanced) I am going to be finishing off soon, which I want to replace the output stage of a Nuwave DAC with, which will be the acid test... that should be completed this year.
 
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You mean [the inductor's series resistance should be] 0.010R, right? Is that value calculated ...

No it's simply the number that Bourns quotes in their datasheet. Mouser's sales page has a link to it. Snippet below.

After completing a three week refresher course in Signals And Systems, finishing all 100 homework problems in the Schaum's College Outlines practice book, and drinking two cups of strong coffee,

you might be be ready to derive and solve the equations (Laplace transforms) which govern this circuit. Then decide which of the variables are fixed constraints and which are free parameters, and iteratively converge toward a final design. Performing the exercise will remind you why it takes four years and not four weeks, to finish a BSEE.

_
 

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Back in late April, I used the website pcbshopper dot com to get price quotes from 20+ different fabs. I picked the fab with lowest price that day AND who offered DHL express shipping; in my experience, DHL gets boards to California faster than anyone else.

Here's what I paid for 30 boards, and here's how long it took. This was five months ago and things may have changed; get a fresh quote and make a fresh decision.

_
 

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TNT

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Thats cool. Looking at the costs, its this 0,04 ohm that sticks out. Isn't there a way to realise this with a specified length and gauge for a copper (etc) single core wire?

How about the copper on the PCB - what should I have ordered for this to work as intended?

Did I miss something here...?

//
 
Back in late April, I used the website pcbshopper dot com to get price quotes from 20+ different fabs. I picked the fab with lowest price that day AND who offered DHL express shipping; in my experience, DHL gets boards to California faster than anyone else.

Here's what I paid for 30 boards, and here's how long it took. This was five months ago and things may have changed; get a fresh quote and make a fresh decision.

_

That is what I paid yesterday, so prices have not changed.
 
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It might be a fun group project, for members to work together and create a deeply cost-reduced version of PO89ZB ; or perhaps even a re-design. If you're willing to use SMD components, and if you're willing to buy from eBay and AliExpress, despite the huge number of counterfeit parts that flow through them, maybe you might consider

these on eBay

or

these others on AliExpress

And who knows what other savings you might discover if you dig hard? It might be fun!