OK, so here is a little nerd experiment I did with S1 connected to my Galaxy S9 and LPGT/LP6k, monitoring 5V supply in series to see what's happening with a current draw from a source.
First of all, does not matter if it's a smartphone, android dap, or non-android DAP. And it is also the same if I'm using IEMs connected to 4.4mm or 3.5mm output. Plus, the same either if I'm playing mp3, flac, or DSD files. The current draw is stable and reads the same. At a normal listening level in high gain, S1 is drawing about 70mA of current from the source. But when you raise the volume higher, it can go up to 80-90mA. And so that I don't blow my iems, I used ibasso load dongle and see the current going up to 90mA at volume level of around 95-96. When it is closer to max 100, it probably in some saturation state where the current draw is oscillating a bit.
Again, keep in mind, I'm "sniffing" the amount of current drawn from the source by S1 from usb-c output. This is not headphone output or anything related to audio output.
Under the same test conditions, here are how much some of the other USB DAC/amp dongles draw current from the same sources at the same normal listening level:
Lotoo S1 => 4.99V, 0.070 A
AudioQuest DF v1.2 => 4.98V, 0.100 A
Hidizs S8 => 5.01V, 0.030 A
iBasso DC01 => 4.98V, 0.90 A
Cozoy Aegis => 4.93V, 0.130 A
