Type-IX phasers are carried aboard Ambassador Class, upgraded Intrepid Class and similar Starships. They are a big step above the Type-VIII, and are currently used on Starships with a limited power supply -- either due to age or high velocity capability. Some Starships with Type-IX phasers have been upgraded to Type-X capability. This has resulted in improved power per emission, but has also decreased the rate of firing in a trade off for the power.