These are the only photo that I can find. The class D power amp is a Pete Millett design.
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Okay, I pulled the trigger on parts to do one supply. It's the standard Pass configuration with a little extra capacitance and the exception of using surface mount resistors and bridge rectifiers. The spec calls for 3w resistors but 2w is the highest high quality SMD I could find. So, I doubled up from four to eight and made the necessary adjustments in resistance to compensate. That brings the handling up to 4w. NO CLUE if this is acceptable practice but I need to save space and that was the workaround 🙂 Not sure how good the Triad Magnetic toroids are for audio but I went with their special medical grade shielded model so hopefully it does the job. I'll attach the parts list spec. and the rough draft of the filter board with SMD, sans the bridge rectifiers. Those are pretty tall so they will likely not go on the board. I fully expect the case to run hot so I went with healthy spacing of caps and chose long life units with extra voltage headroom. I hope to get started on making the board in the next few days-
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More is better.
However, do you really need more ?
I got away with a pair of 47,000uf's in a 225WRMS amplifier used for a mobile disco.
It got hammered every night at gigs and I had no problems with it.
However, do you really need more ?
I got away with a pair of 47,000uf's in a 225WRMS amplifier used for a mobile disco.
It got hammered every night at gigs and I had no problems with it.
I have a beastly 300w A/B with 28kuF per channel, IIRC, so that doesn't surprise me. The main rational is to pack a 1U chassis to the limit, and this scenario will have the top and bottom bulging trafo and caps lol. I'm glad no one (yet) seems to disagree with the spec in terms of component quality or the tweaks for surface mount. It will be much easier to dial it back from here rather then having to go bigger.
A little mental exercise for Christmas - vast majority of "electricians" don't care about the practical realization of their layouts; they also don't know about the sonic influence of circuits that are as accurate as possible, of a current as accurate as possible;-)
They are just not audio freaks;-)
They are just not audio freaks;-)
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Some Christmas presents arrived and I am enjoying my oopsies, including multiple ordering mistakes and half of my caps are nuked. On the upside, I'm testing out a raw battery split-rail and it absolutely rocks! LIFEPO4 chemistry turns out to be perfect due to it's insanely flat discharge curve; one of those happy accidents that was not part of the plan. Here's the good stuff https://batteryhookup.com/products/4-pack-a123-3-2v-31ah-lifepo4-cells
What went wrong so far:
-Trafo is wonky geometry for packaging and the spec'd dimensions are badly undersized. It would not even fit in my layout.
-Only ordered half of the needed SMD resistors
-SMD bridge is way wrong (smaller than the resistors LOL). I accidently spec'd to surge current and didn't pay attention to the tiny dimensions.
-Toasted half of my capacitors due to reverse polarity
Also, as I inspect cumbb's sketch I'm wondering more about them; it's less obvious the more I think about it and may it's not just a symmetry thing per se...
What went wrong so far:
-Trafo is wonky geometry for packaging and the spec'd dimensions are badly undersized. It would not even fit in my layout.
-Only ordered half of the needed SMD resistors
-SMD bridge is way wrong (smaller than the resistors LOL). I accidently spec'd to surge current and didn't pay attention to the tiny dimensions.
-Toasted half of my capacitors due to reverse polarity
Also, as I inspect cumbb's sketch I'm wondering more about them; it's less obvious the more I think about it and may it's not just a symmetry thing per se...