Originally Posted by stormwind13
What would be nice is if someone would import a batch of them, and offer them custom tuned to people. With what the cost to buy, I'm sure the right person could set up a mod shop to increase capacitance, weed out reliability issues, etc, and still have room to profit. If I had the electronics knowledge to do it, I would myself.
Actually, after 3 years of testing different versions of these Class D or TD or whatever they wanna call their switching supply amps, and having gained a lot of knowledge about how they work (or are supposed to work), I'm considering doing just that.
IMO, the biggest problem with amps that underperform and/or stop working is not the caps, it's the BJT and Mosfet output transistors. The brands are all over the map, some are counterfeits, some are discontinued buyouts, some are no-name/no-model #, some are rejects (or certainly should have been), some are the wrong component for the job, etc.
One amp, for example, had transistors that were warped, so instead of sitting flatly on the heat sink, they were not even touching the heat sink other than 2 edges. May as well not even have heat sinks and fans.
I've tested the caps and many other parts and found them to be consistently accurate... except in the case of the output transistors.
Since there are over 50 of them in the 14000, they can cost as much as these agents sell the amps for or as little as a few USD on the black market, etc.
The only other problems I've had have been wiring routing problems. Although that can be a catastrophic fail, it's easy enough to check before I crank one up and the factories seem to respond well to improving QC on things that involve human error and not cost of parts, especially if there are continued sales.
I'm looking into replacing all output transistors so that I know they are always consistent and meet spec and work properly. I've tried to spec them from the factory. They nod and then send whatever. If I can find a good component from a reputable and stocking supplier and a decent enough price and the replacement goes well, I'll let everyone know what the bottom line will be out the door or if the whole exercise was a fail or just not worth it.