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

I took liberty to follow the same link, change location for US and chose $ as currency (assumed also convenient). Gives $3.04 inc. shipping and tax for a single box. Thought that would give you guys from "the other side" a better baseline. So link is now in English... and of course can all be changed to Canada and CAN$ etc. should you wish so...

Aluminum Project Box Enclosure Case Electronic DIY Instrument Case 80x50x20mm Drop Ship|Wire Junction Boxes| - AliExpress

Hope this works and helps

Claude
PS: casing is aluminium, looks a bit better than plastic but of course conducts current...
 
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I was guilty of dismissing high current SMPS for my power amps after having made a pathetic attempt at testing one out a long time ago to reinforce my bias.

These power convertors have improved a ton in the intervening 20 years and after adding a LCfilter and cap multiplier, I am now resoundingly converted. The combination sounds (and measures) better to my ears compare to ordinary toroid+lotsofcaps (by a lot) and still slightly better than toroid+lotsofcaps+CX. Worth trying for sure.
 
This was for an amp similar to a usual blameless amp - that was the last BJT amp I made.
I didn’t find much difference to the top end (surprisingly to me) but that there was very much much better mids especially at medium to louder volumes. Drum stop start was also a good barometer of improvement.

the linear psu for comparison was a simple toroid, soft recovery eth0806 or similar diodes, and nichicon elcos .. so nothing fancy.
 
I'm a UK based member new to DIY audio. I'm really interested in this project but don't have the skills (yet) to have a go and make this filter. Can someone make something for me based on this design and I will happily pay for everything including your time? I need a between 6-8VDC output with no more than 1A. I have a selection of quality of SMPS's from FRIWO. It's for a USB reclocking audio device that benefits from a low noise/ripple supply. Thanks
 
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For the amount of money you're going to spend on consulting man-hours, you could instead purchase a brand new laboratory power supply such as the B&K 9130B (here is one sales site). Connect it to your USB reclocking audio device and sleep soundly, knowing you've got a professionally engineered low noise / low ripple supply.

OR, use the B&K as your Gold Standard against which all DIY supply projects are measured. Hook up a FRIWO supply to the USB reclocking audio device and listen. Compare the sound vs what you hear with the B&K lab supply. Which do you like more? Now install one of these little PO89ZB filter PCBs in series between the FRIWO and the USB reclocking audio device. Listen again and compare to the sound of the Gold Standard. Repeat as necessary. When your experiments are completed, you've hopefully got a great sounding DIY supply that equals or exceeds the Gold Standard. AND you've also got a helll of a great lab power supply to use for the rest of your DIY audio hobby career.
 
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I'm a UK based member new to DIY audio. I'm really interested in this project but don't have the skills (yet) to have a go and make this filter. Can someone make something for me based on this design and I will happily pay for everything including your time? I need a between 6-8VDC output with no more than 1A. I have a selection of quality of SMPS's from FRIWO. It's for a USB reclocking audio device that benefits from a low noise/ripple supply. Thanks

droom, sorry to bother, but—this project, with 9 parts (plus the wires) would be a perfect starter to get into the DIY dungeons. I'd kindly suggest you get somebody willing to help you out on the details, but do the solder smoke yourself.

It's not that hard, but it's indispensable if you want to get into it.

(I actually would prefer not to, because I'm really a novice, prone to errors...)
 
Fwiw, here are some interesting measurements from stereophile between amps using linear vs smps supplies for your enjoyment.
Not at all a scientific comparison, but it seems at least plausible that some of the differences are due to the use of switching supplies.

This is a also a nice five min watch: Audio Myth - "Switching Power Supplies are Noisy" - Benchmark Media Systems


On another thread i also did measurements on some supplies and the effects of a SMPS filter..I didn't know at the time that there was already a project cooking on this else i'd have waited for an expert designed one! I'm really looking forward to trying out the design from Mark when its published!

post #41:
Mean well vs generic power adapter vs audio oriented smps

Cheers,
 

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A quick question: I can see how you can generate the positive rail with the Mean Well you are using, but how do you deal with the negative power rail? How did you connect I presume a second SMPS this to make + and - power rails working around the same ground?

Thanks, interesting!

Claude
 
It is probably wise to also compare PS output impedance vs frequency and capacity to deliver amperes.

Claude
Great suggestion -,I’m sure I’ll get round to doing it at some point and I’ll,post that when I eventually do.

Based on your graph only, it appears that a linear PS could have bettered the SMPS on all accounts provided the main's frequency and its multiples would have been better filtered out?

Dunno but maybe avoiding ripple and harmonics in the audible spectrum isn’t such a bad idea either :D

A quick question: I can see how you can generate the positive rail with the Mean Well you are using, but how do you deal with the negative power rail? How did you connect I presume a second SMPS this to make + and - power rails working around the same ground?

Yup that’s correct - two mw smps ( with LC filter and CX ) arranged in series...
 
I'm a UK based member new to DIY audio. I'm really interested in this project but don't have the skills (yet) to have a go and make this filter. Can someone make something for me based on this design and I will happily pay for everything including your time? I need a between 6-8VDC output with no more than 1A. I have a selection of quality of SMPS's from FRIWO. It's for a USB reclocking audio device that benefits from a low noise/ripple supply. Thanks

This filter is perfect for your first DIY project.

You can do this. We will help.