@fredrik222 seems to be the only one who knows what he is talking about.
An Ethernet switch either works completely & flawlessly or fails miserably. There is no in between. Since cheapish switches are designed to mostly work in 1 gigabit range, unless you exceed the 802.11 specs they ALL work, for them, audio level speeds is a walk in the park.
Unless there is something electrically wrong with the switch when you first use it, a different power supply will NOT make a difference.
Keep your money and simply buy a $30 switch. It will be MORE than adequate. Just make sure that its existing power supply actually works and make sure the wiring you add is at least category 6 compliant and you will be fine.