Class D and Power Cables

Ralph, I don't necessarily disagree, and I would suspect that in general Class D amps may indeed tend to be more sensitive to power cord differences than other classes. But wouldn't the limiting of high frequency high current bursts typically be mainly a function of the house wiring, not the power cord, due to their difference in length, and hence inductance?

Although it would certainly seem conceivable that in some cases other power cord effects, such as voltage losses and coupling of amplifier-generated noise from the power wiring to other parts of the system, could be disproportionately affected by the power cord in comparison to the house wiring.

Best regards,
-- Al

Hi Al, I'm sure external wiring has effects. But we don't get to change that stuff very often, so we also don't get to see how it affects things. The power cable OTOH is something that is easily experienced, and I have been able to correlate audible effects based on some fairly simple measurements.

The other thing I did not mention is voltage drop across the power cord. This can affect any larger amplifier that has a large current draw. I've seen a 2 volt drop across the cord rob an amplifier of nearly 30% of its output power!

How can that be Ralph?? 2 volts drop = 30% output power reduction??

Thankyou Ralph and Al for a learning exsperience with the post the both of you done, I highly enjoy what the both of you always have to say., cheers

Bifwynne, That was on a 100-watt tube amplifier.

The 2-volt drop is bigger on the secondary side of the power transformer(s).

If you think about it, the heaters cool off a little, the B+ is a little lower, the power tubes are not conducting as hard, the driver circuit can't swing as much voltage. It all adds up.