AmyAlice: DC filter for SMPS, using 2 feedthru capacitors + SMD assembly. max 3A & max 48V

Great idea @BRN !! ACA Mini uses a 24VDC power supply so you're well below the max voltage; AND it draws about 0.5 amperes per channel so you're well below the max current too. Please let us know whether installing AmyAlice has changed your subjective listening enjoyment.
 
Looks like I'm a couple of weeks behind you here. Is the AmyAlice board fixed or resting on something? Or just floating on the wires down to the ACA Mini power input pads? I'm planning to use one for an ACA Mini, so your work and results here are of interest.

Thanks, Skip
 
I only had a chance to listen for a couple of minutes. Initial impressions are positive and worth putting it front of the ACA Mini.

I did secure the AmyAlice to the caps. You can see what I did in the picture.

I did use a P089ZB with the amp before, and still think that there was an improvement. That just could be new poppa syndrome, but don’t think so.

IMG_5510.jpeg
 
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Simple and elegant implementation! Compliments the ACAmini quite a bit, nicely done.

I'm sure you are not dreaming, my initial experimentations with AmyAlice point to it being noticeably better than the already excellent P089ZB.
 
... as Forum readers are well aware, there are lots of new electronic components which are offered ONLY in SMD packages. High volume electronics manufacturing is all-SMD in Y2023, therefore component suppliers meet their customers' needs with all-SMD parts. This is particularly true of new components, which, by the very definition of the word "new", do not exist in legacy thru-hole designs. ... A couple of new, SMD-only components are now available, which enable much better performance (i.e. greater noise attenuation) in SMPS DC filters.

This may explain why members prefer AmyAlice
 
AmyAlice builders and thread readers might also be interested in a new Forum discussion thread which was recently created:


Forum member @schultzsch has laid out a new PCB which includes the AmyAlice DC filter and a capacitance multiplier using bipolar transistors. PCB manufacturing Gerber files are freely downloadable. Take a look if you are interested.
 
Hey guys
I tried to build a filter using SMD + discrete components. Make the most of the components you already have.
I changed the circuit slightly and added a common-mode rejection inductor in front of it.
I had two switching power supplies in my hands for testing, and they were so noisy that I couldn't use them to measure the THD+N of the amplifier.
It's time to try an external filter. I'll share the final results below in a few days. Hope all the best.😛
 
Progress report and a question or two:

Finished the first of my boards. It was much easier than my earlier experiences with the large pads. I'll clean it up in the morning and grab a picture. The Floor Monster claimed only one resistor.

Fifteen years or so ago, I built a Hagerman Bugle, and he included similar instructions on board/flux cleanup, suggesting submersion in isopropyl alcohol in a shallow dish up to the board top surface for while and scrubbing a couple of times. Is there a time of alcohol exposure issue with any devices, active or passive, cleaning up this way. Alternatively, are there commercial cleaners worth using. I've never had a problem with the submersion over perhaps 15 builds.

I metered the resistors and the smd caps after soldering,and all seems well. I think the diodes are right though the faint symbology is mildy ambiguous. Any useful checks I should make?

Thanks,

Skip