No additional heastsink at the moment, but cooling is always going to be a problem inside a sealed cabinet full of (insulating) stuffing. I had hoped that the high conversion efficiency of the switch mode supply would have been sufficient, but it looks like that was wrong. I can try adding a heatsink, but it will still be trapped inside a sealed box.How are you heatsinking the SMPS PSU? It will need some serious cooling.
No additional heastsink at the moment, but cooling is always going to be a problem inside a sealed cabinet full of (insulating) stuffing. I had hoped that the high conversion efficiency of the switch mode supply would have been sufficient, but it looks like that was wrong. I can try adding a heatsink, but it will still be trapped inside a sealed box.
Thanks! Hopefully I can avoid mounting the PSU outside of the cabinet, but it would be doable. The good news is that the buzzing has stopped this morning now that things have cooled down, so I can look at adding a finned heatsink.It will need to be mounted on a finned heatsink with access to external air or it will fail/shutdown or just burn up the components prematurely.
Their efficiency may be good at near to full load, but at low loads, they can be poor.
Looks like the buzzing was due to a dodgy XLR cable. I fitted a finned heatsink to the PSU anyway and everything is working well now.It was working well, but was on all day today and has started buzzing! Some kind of heat related issue I expect. It will require more investigation tomorrow...
Nice try. It appears 1/2 of the solder job looks OK and closest solder looks a bit, "Cold." What you need is some liquid rosin flux. It makes soldering easier to do and the end result will look much better and be a better contact too. Cost is maybe $7 to $15 depending on the size of container that you buy.I have just repaired the mechanical keyboard with KAILH switches (Titanwolf Imperial). I bought it by eBay for €21 and got today. It should be B-Ware "refurbished". But one Key was death :-(. One diode was loose and fell down when the housings were unscrewed. Now works fine again. This was my first SMD soldering job .
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View attachment 250329
class D filter for noise and distortion measurements
Though I do not have special problems with soundcard saturation from class D amplifiers during measurements, I have decided to make a simpler version of something like AP AUX-0025 filter. I made an RLC filter that is possible to use with both single ended and BTL output class D power amplifiers, in 20Hz - 20kHz band.
It looks like this, and it has air-core inductors and MKP capacitors:
View attachment 171316
and this is the frequency response:
View attachment 171317
Not ideal, but usable.