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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.
Post Subject: For your oscilloscope imagesPosted by Antonio J. on: 6/20/2007
I suspect the APS does more or less the same that my friend proposed. It probably has a class D amp which makes some kind of PWM with a so so smoothing circuit, hence the tooth saw trace of the voltage line, some PS which probably is a switching one feeding a battery charger, and an oscillator tuned to produce a 60Hz wave with the amount of signal required for the 120V output.
Its problems may come from a not so good D amp that distorts the signal when load increases. Why? I don't know, I'm no technician, I ignore how a switching or battery power supply interacts with a digital amp when the load increases. Maybe a traditional PS were a better approach.
My concerns about impedance matching were more focused on the possibility that the input impedance at the system's power supplies was high, or at least higher than the average 4 to 8 ohms that speakers have. I don't know how digital amps deliver power when plugged into higher impedances, nor how they work if that impedance is not purely resistive. I don't know if an input transformer has high amounts of inductance that can be too demanding for a digital amp. Maybe the problem you're experiencing with the APS is not as much for the power demands of the Melquiades as for its input impedance at the PS.
This would be a very affordable DIY option, but regarded from the mains net isolation perspective, maybe the AC generator and electric engine makes more sense.
Regards,
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