@Confused - Firstly, well done for taking the bull by the horns and for avoiding any accidents in the process!
Interesting results.
On the face of it, the numbers show that the power output is increasing more or less linearly as you increase the volume in fixed logarithmic steps, which is good to see. There are some fairly wide variations but it's possible that these are as much due to the meter and assumptions about the load as to the amp itself, I guess.
However the fact that there's no sign of limiting might be because the input level was too low to push the amp into that mode even when the gain was turned up to full (0 dB).
Do you know what input level you were pushing into the amp, either in dBFS or volts RMS -- and if the latter, what's the configured maximum level of the corresponding input?
It might be interesting to see corresponding numbers for (say) a 1 kHz input at the same input level.
I tend to agree with you that for all practical purposes if there is an output power limit that affects high frequencies it probably doesn't affect music much because there isn't much power at 10 or 15 kHz anyway. But there is still something niggling away at me asking: if it can output 1000 Watts at 1 kHz, why can't it also output 1000 Watts at 15 kHz? Is the output power limited to protect the load, or to protect the amplifier itself? Maybe there is something inherent in the ADH design that limits the power output at high frequencies?
Now I start to think about it: perhaps the digital (PWM) output section is less able to dump current into the load as the frequency increases. It does have a ton of inductance in series with the load, after all. In the extreme case if the frequency is high enough, perhaps only the class A part of the ADH section might be able to drive the load. (I'm just thinking aloud here, and could be on completely the wrong track so don't take it too seriously.)
I remember hearing -- but never seeing -- that Devialet used to demonstrate the ADH section of the amp by removing the class D output section and just running it as a class A amp. There's a very vague memory that the output power in that mode was about 5W. Hmmm.
Interesting results.
On the face of it, the numbers show that the power output is increasing more or less linearly as you increase the volume in fixed logarithmic steps, which is good to see. There are some fairly wide variations but it's possible that these are as much due to the meter and assumptions about the load as to the amp itself, I guess.
However the fact that there's no sign of limiting might be because the input level was too low to push the amp into that mode even when the gain was turned up to full (0 dB).
Do you know what input level you were pushing into the amp, either in dBFS or volts RMS -- and if the latter, what's the configured maximum level of the corresponding input?
It might be interesting to see corresponding numbers for (say) a 1 kHz input at the same input level.
I tend to agree with you that for all practical purposes if there is an output power limit that affects high frequencies it probably doesn't affect music much because there isn't much power at 10 or 15 kHz anyway. But there is still something niggling away at me asking: if it can output 1000 Watts at 1 kHz, why can't it also output 1000 Watts at 15 kHz? Is the output power limited to protect the load, or to protect the amplifier itself? Maybe there is something inherent in the ADH design that limits the power output at high frequencies?
Now I start to think about it: perhaps the digital (PWM) output section is less able to dump current into the load as the frequency increases. It does have a ton of inductance in series with the load, after all. In the extreme case if the frequency is high enough, perhaps only the class A part of the ADH section might be able to drive the load. (I'm just thinking aloud here, and could be on completely the wrong track so don't take it too seriously.)
I remember hearing -- but never seeing -- that Devialet used to demonstrate the ADH section of the amp by removing the class D output section and just running it as a class A amp. There's a very vague memory that the output power in that mode was about 5W. Hmmm.
Roon (Mac Mini), Wilson Benesch Full Circle, Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK
