I've been a reader of ASR for awhile now and it's inspired me to try my hand at making some measurements. I have both a Topping D50 and a MiniDSP DDRC-24 and recently I came by a Yamaha MG10XU USB mixer that I thought I might be able to make some measurements with.
The Yamaha runs about $200 on Amazon, so I didn't expect a lot. But, since @amirm showed there's a significant performance gap between the D50 and the DAC portion of the DDRC-24 I thought I might be able to measure some differences between them. Instead, the FFTs I captured from both DACs looked nearly identical, which I presume is because its ADC isn't up to the task.
So, my question is this: If I haven't managed to measure the differences between the D50 and DDRC-24, what have I measured, if anything? Does it tell me anything about the Yamaha MG10XU other than it's probably not going to produce lab-grade measurements?
FFTs are 64k, Hann window, 4 averages. First up is the spectrum FFT of 1kHz tone at 0dBFS. The green is the DDRC-24 and the brown is the D50. As you can see from my, presumably flawed, measurements the FFTs look nearly identical.
The next measurement I tried was the jitter and noise "j-test" signal. I couldn't find it in REW's signal generator so I used @miero 's excellent post about Sox as a guide to generate my own j-test signal. In this plot the green is the D50 and the orange is the DDRC-24. Again both FFTs are very similar.
The Yamaha runs about $200 on Amazon, so I didn't expect a lot. But, since @amirm showed there's a significant performance gap between the D50 and the DAC portion of the DDRC-24 I thought I might be able to measure some differences between them. Instead, the FFTs I captured from both DACs looked nearly identical, which I presume is because its ADC isn't up to the task.
So, my question is this: If I haven't managed to measure the differences between the D50 and DDRC-24, what have I measured, if anything? Does it tell me anything about the Yamaha MG10XU other than it's probably not going to produce lab-grade measurements?
FFTs are 64k, Hann window, 4 averages. First up is the spectrum FFT of 1kHz tone at 0dBFS. The green is the DDRC-24 and the brown is the D50. As you can see from my, presumably flawed, measurements the FFTs look nearly identical.
The next measurement I tried was the jitter and noise "j-test" signal. I couldn't find it in REW's signal generator so I used @miero 's excellent post about Sox as a guide to generate my own j-test signal. In this plot the green is the D50 and the orange is the DDRC-24. Again both FFTs are very similar.