Based on my past experiences, yes! In Korean amplifiers like these, the power supply has poor efficiency when it is only turned on. I have heard of a modification that allows to improve the efficiency by lowering the current absorbed when empty. Personally, some time ago I tried to increase the dead time in the power supply, really tiny stuff, but it allowed to drastically lower the absorption at zero load. The problem is that the rail also dropped drastically and as you can imagine, the power output of the amplifier would have also dropped. Then I noticed a guy, Sam, aka Barevibs on youtube, who lowered the switching frequency of the power supply noticing a lower absorption, given by the lower heating of the power supply mosfets. But it's all very relative, you have to understand if doing these things, something else gets worse.