Comment by saltcured
4 days ago
Yes, perhaps the amplitude was subtly different.
This was supposed to be running the DACs to match the source configuration, not resampling into some common format. I think that is an unavoidable part of the whole end-to-end ABX test concept.
Maybe it would be interesting to up-sample back into 24/192 and play both in that mode. But then people would argue about what type of up-sample to use.
I was in my mid 20s for this test. I understand my high-band hearing was better back then.
Speaking about up-sampling, Im curious to know your opinion on the benefits of it. Im sending CD resolution audio as well as web streams from soundcloud.com to cambridge audio azur 840C and its not clear if its the up-sampling that makes the difference or their per channel wolfson dac arch. The iPod Video with their dac sounded amazing with just normal AAC files compared to the iPods before or after it.
Any high end audio dac is internally running at a much higher sample rate-- that's what it takes to get their delivered performance with the silicon that's available. Its up-sampling process was designed by the designers of the DAC with intimate knoweldge of its analog properties.
Second guessing it by upsampling in front of it seems dubious to me. It might help in some cases where the DAC designers were thinking of different objectives or just didn't do a great job. It might also help with some other issues, like if the dac is timed off the input clock and the input clock sucks and the upsampler retimes the signal.
Of course the upsampler designers could also get it wrong, be aliasing the hell out of the results, and happen to like the sound of the corrupted audio. :P
The effects are all objectively measurable however-- with expensive equipment at least. I think I'd want to set test results with a particular hardware combination before sticking an upsampler in it. OTOH, if there already was one there because it's just some built in feature of some kit I wanted to use otherwise, I wouldn't worry much about it. Particularly if that kit has been reviewed by people with proper test gear and they didn't decide that it was broken.