It is tiny but quite powerful. For full power output needs some preamp from phone output. The sound is clear with enough bass. With short test on Max volume it od not heat up even without heatsink. For longer use the heatsink is necessary I guess.
I orderd the mini amplifers c/w volume control. However they sent me the ones without the volume control. Not a big problem for me but I should have received what I ordered. Thank you for sending an extra amplifier in lieu of.