The H9 has a regulated power supply, so the voltage alone isn't the complete picture of its power supply needs.  What matters is that voltage is an appropriate range with enough current to meet the minimum wattage requirements.  

If you look on the back of the H9 by the power jack you'll see the screen printing that reads 9-12 VDC, 4.5W.   We know that Watts = Volts * Amps, so doing the simple math…..at 9 Volts you'll need at least 500 mA, and at 12 Volts you'll need at least 375 mA for normal operation. 

Of course we can't vouch for every power supply. Just because another supply has the right numbers doesn't mean it's giving clean even power.  Obviously we can't guarantee 3rd party power supplies outside of our recommendations.