from the graphic it results there is no difference between the battery and iPower elite because the variation is well below the digital signal voltages (0.4 V). The second source (which is not a battery) can alter the signal in the low frequency zone.
Do you have a similar graphic with the source that comes with the IFI Zen stream?
We do not have one. It will take us a few days, but I'll try to get you some more measurements.
Another question (referred only to streamers connected to externals DAC's):
Considering that the streamer only passes the digital signal to the DAC is there any difference between the IFI Zen Stream and let's say a very very expensive Streamer (like one from Aurender) in terms of the signal that reaches the DAC?
I know the Aurender might have internal HDD's and a different interface etc. but I'm only interested in the quality of the signal that is transferred to the DAC.
Basically the DAC is receiving either zero or one (assuming the source is good enough and there is no jitter).
This being said, I don't understand how some people state that one streamer or the other can make the sound to be more or less lean, more or less bass or the stage wider etc ... The digital signal should either get to the other end or not. It should be like on a TV: you either get the digital image completely or when you have a bad signal you get undistinguishable dots.
The digital signal. That is a good question. Let's take a very simple set-up as an example. Source, streamer and a DAC. The source aims to send the file in its highest quality, streamer (as an extra device in that chain) aims to add as little distortions as possible to the DAC, which again often improves and converts the quality of the track.
In an ideal, perfect, studio-like environment, if the output on both of your streaming devices is digital there should not be any difference, as long as the input is exactly the same and both are bit-perfect. The difference comes along when it comes to the parts, interface, output quality, filters in ethernet, filters on outputs, inputs, built-in DACs, drives. Additionally, they are not always bit perfect and often do not have the same quality outputs. The source, the streamer's outputs, the dac - they will all play an important role. For instance, even though the high-res streaming platforms may offer the same file format, people tend to detect tremendous differences between them. The same analogy applies to the streamers.