Not sure anyone can clear this up but ....
I wanted to compare the Node 2i DAC to my Channel Island VDA-2 DAC.
I've got two areas of confusion. One relates to loudness and the other to sound quality.
Lets start with the loudness area in this post.
So I set up the following two paths to my amp:
Wi-fi -> Node 2i -> Coax -> VDA-2 DAC -> PreAmp/Amp CH 1 Balanced Input (XLR)
Wi-fi -> Node 2i -> RCA -> PreAmp/Amp CH2 Unbalanced Input (RCA)
For a fair comparison, the two paths need to be normalized to the same loudness level. As described below, I can adjust my amp to get equivalent loudness, but I'm trying to understand quantitatively where the difference is coming from.
Neither DAC supports the other input type so I don't have a choice to match these. I have the Node 2i set to "Fixed Volume". The VDA-2 has no volume controls. I'm noticing to get roughly the same loudness levels, I'm having to increase amp volume on the unbalanced input about 6-8 dB. The amp manual describes its display as "Volume". I was checking the loudness dB levels with a phone app to match them up, so I should be in the ball part for accurately setting the amp to match the loudness levels.
I've seen other posts that say that the Node 2i seems to need more Gain to match other sources (not sure whether they are balanced or unbalanced from the posts). I'm wondering what part of this could be due to balanced vs unbalanced inputs.
Assuming the amp does not compensate for the input type, my thinking is something like:
RCA unbalanced - should be -10 dBV -> 0.316 Vrms - should be 0.447V peak voltage
XLR balanced - should be +4 dBu -> 1.228 Vrms- should be 3.147V peak to peak (differential signal)
20 log10 (3.472/0.447) = 17.8 dB which doesn't go with my 7 dB of correction.
Am I looking at this wrong?
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