Will try the TOSLINK soon, thank you. Indeed, there is some noise visible on my scope and ARTA measurements when inserting the USB cable, but this normal and is happening on all my DACs (none are having USB isolation). Given that I can barely hear PLAYMATE's background noise in the middle of night (very silent environment) with my test headphones I can strongly recommend PLAYMATE as a very good all-rounder combo. Worth mentioning again that my test IEM's are pretty sensitive: - 16 Ohms - 103dB/mW - 121dB/1V So with 900mV I get 120dB SPL and getting -85dB lower I only need 50uV (usually my ears can't hear a background noise lower than -85dB). On my scope I was able to get a noise of 59uV vs. PLAY that had 111uV (I wasn't using the cleanest setup ever, so in real life and with an AudioPrecision, output noise might be lower). To my ears, PLAYMATE (LME49720/JRC5532DD) has a very low background noise, like 10-15% lower than PLAY (NE5532/5534). PLAY vs. PLAYMATE (background noise) Worth mentioning that on ARTA this noise is somewhere between -140dB and -130dB, will post updates soon. Also, worth mentioning that max. ouptut voltage on the headphones jack is identical on both PLAY & PLAYMATE: 10V RMS, theat means 0.167mW/600Ohms. That voltage corresponds to the volume knob having a position of 96% for the PLAY and 98% for the PLAYMATE. Given one of my previous posts above, regarding the level matching between PLAYMATE and PLAY for my HE-560, seems that PLAYMATE has a more gradual volume, sort of logarithmic volume, offering a slower volume increase. PLAY vs. PLAYMATE (both having a 10V RMS output voltage) P.S.: If you want to try PLAYMATE with an extremely sensitive IEM like FiiO FH5, then background noise will probably be a bit too high for you, given their sensitivity of 112 dB/mW (129.2dB/1V) and their impedance of 19 Ω. However, any 16-32 Ohms with a sensitivity lower than 105dB/mW should be a great pair with PLAYMATE.