Hi,
I would like to measure the quality of alternative power sources for my solid state monoblocks (Spectral DMA-500). These amplifiers have the rise time of less than 225 nanoseconds and a slew rate of 1200 V / microsecond - they need a lot of current fast. The current transients for my entire audio system during playback of music with loud audio transients are as high as 25 A, at 120 V, measured with the time resolution of 40 ns.
Unfortunately, my mains power is compromised with THD of 5% and DC offset of 70 mV; it might also be limited in other ways. So I am looking at alternatives, such as a power regenerator (eg, PurePower+ 3000, which relies on a DC/AC inverter with a battery).
I would like to identify the best power source for my amps by measurement. I imagine a key tool for this purpose is a good oscilloscope (eg, Siglent SDS3104X HD), with sufficiently fast probes whose time resolution is much better than the amp's rise time (eg, differential voltage probe DBP150A and current probe 6030A, with time resolutions of a few ns).
I am inexperienced and naive, but I imagine the following measurement and analysis process:
Should I also do other measurements? For example, should I rank the alternative power sources by the amount and speed of the current they can provide? Alternatively, should I rank them by the speed of change of amp's output voltage (or current?) How do you pros measure the quality of amp power supplies - are they applicable to ranking external power sources? I am guessing that some parts of the power quality analysis by the proposed Siglent oscilloscope could also be useful? Are there specific audio test tracks, perhaps generated with a waveform generator, to extract more information from the measurements?
I would be grateful for any comments or pointers. Anything I should be especially careful about?
Thank you very much!
I would like to measure the quality of alternative power sources for my solid state monoblocks (Spectral DMA-500). These amplifiers have the rise time of less than 225 nanoseconds and a slew rate of 1200 V / microsecond - they need a lot of current fast. The current transients for my entire audio system during playback of music with loud audio transients are as high as 25 A, at 120 V, measured with the time resolution of 40 ns.
Unfortunately, my mains power is compromised with THD of 5% and DC offset of 70 mV; it might also be limited in other ways. So I am looking at alternatives, such as a power regenerator (eg, PurePower+ 3000, which relies on a DC/AC inverter with a battery).
I would like to identify the best power source for my amps by measurement. I imagine a key tool for this purpose is a good oscilloscope (eg, Siglent SDS3104X HD), with sufficiently fast probes whose time resolution is much better than the amp's rise time (eg, differential voltage probe DBP150A and current probe 6030A, with time resolutions of a few ns).
I am inexperienced and naive, but I imagine the following measurement and analysis process:
- Play a short audio file with powerful and fast transients (eg, drums).
- Measure the voltage on the amp output, with a resolution of a few nanoseconds (which is much shorter than the amp rise time).
- Possibly also measure the voltage of the audio signal on the amp input, instead of using the source audio file itself, to eliminate the playback hardware before the amp input from consideration.
- Quantify the correlation between the audio signal and the amp output voltage.
- The power source with the highest correlation is the best power source.
Should I also do other measurements? For example, should I rank the alternative power sources by the amount and speed of the current they can provide? Alternatively, should I rank them by the speed of change of amp's output voltage (or current?) How do you pros measure the quality of amp power supplies - are they applicable to ranking external power sources? I am guessing that some parts of the power quality analysis by the proposed Siglent oscilloscope could also be useful? Are there specific audio test tracks, perhaps generated with a waveform generator, to extract more information from the measurements?
I would be grateful for any comments or pointers. Anything I should be especially careful about?
Thank you very much!
Class D with Switch mode?
AB with linear?
Just double the current of the Switch modes
Since it is the weakest point.
If the loads are 2 ohms make them 4 ohms
So you use 12 amps instead of 25 amps
Since low impedance loads dont " make" more power
they " use" more power to get to the same place.
Battery powered invertor is weaker than a wall plug.
The amps run on DC so the quality of a power supply making that line straight.
Is the job of the power supply. And also the power supplies ability to provide
a current burst.
We already know line power is ok to horrible. Nothing new.
The amplifiers power supply fixes the curvy line to a straight line.
AC to DC
AB with linear?
Just double the current of the Switch modes
Since it is the weakest point.
If the loads are 2 ohms make them 4 ohms
So you use 12 amps instead of 25 amps
Since low impedance loads dont " make" more power
they " use" more power to get to the same place.
Battery powered invertor is weaker than a wall plug.
The amps run on DC so the quality of a power supply making that line straight.
Is the job of the power supply. And also the power supplies ability to provide
a current burst.
We already know line power is ok to horrible. Nothing new.
The amplifiers power supply fixes the curvy line to a straight line.
AC to DC