I don't have a good IMD measurement for Hypex NC400. At that time, I was testing *input* level to the amp versus IMD which is not good because different amps have different gains. With that important caveat, here it is:If possible, please overlay IMD and THD per frequency with nc400.
And here is the THD+N versus level versus input level for Hypex NC400 relative to Purifi 1ET400A:If possible, please overlay IMD and THD per frequency with nc400.
I hate running that test.....Do you test output impedance?
The X axis is what, watts?Here you go:
View attachment 28951
It would be nice to have a hard on/off switch to avoid the high idle current of the switching power supply. But otherwise, efficiency at power is 90% or so and gets there in a hurry.
It is except that the Purifi was run with two channels running, the AHB2 was with one (compensated in the formula that computes efficiency).The X axis is what, watts?
Excellent, I was hoping it was very good and nothing for anyone to ever worry about, it's rather better than that.Here is the output impedance versus frequency. Note that the scale is in milliohm (1/1000 of an ohm):
View attachment 28956
The spec is 65 micro-ohm at 1 kHz (0.065 milliohm). Likely they measure right at amplifier terminals. Mine are through the case wiring, and into my 3 to 4 feet of wire, connectors, etc. So the amp basically has zero impedance and what is seen is the wiring impedance. No rise with frequency which is very good for a class-d amp.
Considering this is the Purifi thread, read The G Word, written by some Bruno P guy.I'm looking to learn, so links to standards, schematics etc. would be much appreciated.
I'll re-read and hope to understand more fully this time...Considering this is the Purifi thread, read The G Word, written by some Bruno P guy.