Recent content by cjm2077

The more you derate a component, the longer the mean time before failure is. I don't know what standard derating for commercial audio equipment was, but a 120V cap would be about 20% derated, and the 100V would only be 5%. 20% is a pretty reasonable amount of margin. 5% is cutting things...

That's where you're going wrong. You're looking at an example of a waveform where the switching frequency is equal to the output frequency, and while this is how some application of Class D amps that don't care much about THD work, it is not how audio range class D amps work.

I'm just trying to help you understand this. I've designed class D (and E) amps for a living. You seem to have some basic gaps here. But if you don't want my help I won't give it then.

You're missing the most basic element of a class D audio amp. It doesn't switch at the desired output frequency in a sine wave shape. It switches at a much higher frequency square wave shape and that output is then low pass filtered to create a waveform. Turning the fets all the way on or all...

I've used air core inductors in the resonant tank of switching amps, and even at a few uH they get very large. That will depend on how much current handling you need and at what frequency though. I was running up to 500 kHz and up to 100A, so the litz wire got pretty big. The design above...

I took his class. It was very hard, but he was a great guy and incredibly good as a lecturer. As an example, his exams could take 6 hours to finish, but he brought in ice cream from a local place after the third hour. Bose also never intended to pass his company down to his family, give...

I haven't tested audio range component dacs, but no DAC or ADC I have ever designed or tested has shown any break-in characteristics, whether over days, or months. Thermal and long term drift of components exists, and have to be factored into accuracy targets, but someone would have to screw up...

I admire the curiosity, but we're just criticizing the method. I design electronics for a living (not commercials ones, but including DACS and ADCs) and a fair bit of my job is testing and debugging. If a junior engineer came to me with these test results the first thing I would do would be to...

From the manual for the DMM: Temperature Coefficient: 0.1*(specified accuracy) / °C You're also well beyond the rated AC voltage measurement range of 50-60Hz. It's just not the right tool for the job. You're right that over a short period of time it may be precise but not accurate. But...

Try the entire "wellness" industry. It's why they're not the "health" industry any more, because the FDA started checking their claims. Edit: I see @mansr is on the same page as me.

Their desired customer base:

I've used the Node2 (not 2i) for a few years to stream my music collection, and I think it's been a good product. The hardware works the way I want it to, but I'm using it with an external DAC. I've had it both hardwired and connected by wifi, and rarely had issues with the connection...

I got one of those. It's remarkable, much better than the old multi-fx units and amp simulators I used back about 10+ years ago.

Fusing current for a 20 AWG Copper wire is about 60 Amps. Wiring in free space 20 AWG is rated for 11 amps (https://www.powerstream.com/Wire_Size.htm). That would be about equivalent to 500W into a 4 ohm speaker. Continuous. We know no real music/amp/speaker/listener combo is going to do...