Hello, I am a long-time browser, first time poster. I am new with stepper motors, but have a fairly decent grasp on electronics. I am currently running a bench power supply for testing that has a max of 30v and 5a. I am using the KL-4030 driver that accepts 20-40v. (KL-4030 Bipolar Stepper Motor Driver, 40VDC/3A | Automation Technology Inc)
I tried using this combination to drive the following device: http://www.biochemfluidics.com/Products/RV-SN-Electric-Rotary-Valve.asp
It recommends 2.4A and 24v to drive (it's a pretty beefy motor, from what I can tell)
I have been trying to make it work with the power supply I have and the best I can do is get it to vibrate and buzz furiously. As soon as I turn on the power supply it takes a huge drop in voltage (down to about 10-12) and just doesn't turn. I was frustrated so I picked up a stepper motor requiring 5v 2.5amps and everything works exactly as expected. I can, however replicate the buzzing problem by turning down the amperage. As soon as I start turning it down, it will reach a point where the voltage take the same 100 percent (or so) drop and it starts buzzing around like crazy. I turn it down a little more and the kl-4030 driver loses power(i'm sure not enough power draw)
This leads me to believe that I'm going to need a MUCH beefier power supply, as turning it up all the way to 30 volts just gets me the buzzing action. I feel like if I could provide more power that the stepper motor would act the way it's supposed to. First of all, is this logic solid. If so, what would you suggest for power. I'm assuming something with 40v max(thats the max input voltage on the driver) and a much higher amperage. Will I need to build my own power supply, or is there an easier solution? ( I would LOVE to be able to run to microcenter and hack something together than have to wait)

My apologies if I left out any details. I would be happy to post any more info needed to answer any questions!