You can use the headphone out but do not push it past 1 o'clock.
The headphone out is crap with headphones but works well enough as a line out buffer.
This whole thing is powered by usb. Between powering all circuitry inside theres not enough juice left for the outs. On its own it beats atom+onboard pc as long as it's below 60% volume otherwise itll start clipping and audible hiss. Still amazing how much they packed into this for such a low price. Still intend to get a khadas tone board as my main dac though.
Update: Switched from usb 2.0 to 3.0 on the back of pc did increase the signal on the 202hd outs. By like 50%. Dont have to use high gain on atom anymore. Low gain max gets as loud as high gain max used to. XD
This by:
Blumlein 88
"The 204 is listed as a max output of 3 dbu. 0 dbu is .775 volts. So this would be like 1.09 volts which is definitely on the low side. There is a wide range of output voltages, but most DACs will put out at least 2 volts or a touch over +8dbu. So when looking at recording interfaces you'd like to see at least 8 dbu output. Other than the very cheapest ones you see +12 to 20 or 24 dbu. Keep in mind these are usually for balanced outputs. If using adapters for single ended connection you will lose 6 db."
This has to be why the output is lower than usual. The 202hd 1/4 outs are "balanced" but the connection to amp is not so it's -6dB?
Another update: Also connected the 1/4 mono to rca with a set of powered speakers and the max volume was 3 times lower than if it gets the audio signal from my pc onboard. Seems like 202hd outs are really weak and its definitely usb power fault. For headphones into amp out its okay and listening to 202hd internal amp/dac is too.