solderdude
Grand Contributor
For example, opening the top cover of the SMSL box makes amplitude fluctuations much worse due to air convection currents causing temperature fluctuations. Putting a finger on various components indicates that the ES9311Q is the most sensitive element.
I would suggest that opening the box lets in RF. Putting a finger on the chip works as an antenna. The reaction time suggest it is not heat at all.
If that were the case the drift would be slow downwards and slow upwards.
External clocks are for studio usage (word clocks) so various ADCs and DACs sample at the exact same time. The fact that some idiots demand it and claim sonic superiority is another matter.
0.0005dB level difference over 2 minutes time (at any time) is inaudible even when a constant tone is used.
In music the level changes constantly and filter errors alone (due to the way filters are constructed) there will be differences at any time between the described sample value and the actual output voltage that is bigger than 0.0005dB anyway.