three Mojo Hand pedals I recently had on loan, the Nebula was my favorite.The sound of the nebula is just beautiful, it has that sweet chewy almost human tone that the best phasers have. But even more, it was the most versatile phaser I used since my beloved N.O.S. Mu-Tron Phasor II. A pedal which I bought in 1994 for what then seemed like an insane price to spend on a pedal ($150) and sold in 2007 for just over $400.
The Nebula can do everything a Phase 90 can do and can kick in a few Univibe tricks as well. Whenever I plug into a phaser I tend to play the same things. I start with Big Long Song (a progression I wrote in high school with lots of open drones). Next I play Breathe by Pink Floyd, Mayonaise by Smashing Pumpkins and then proceed to geek out on Cure songs. The Nebula nailed all of the above tones, but it was amazing on Breathe. Even better, I was able to get close to the Univibe throb of Hey Baby (Land of the New Rising Son) by Hendrix. It even does a decent leslie simulation with the depth cut to 1/3 or 1/2 way and the speed about 80-90% of the way up.
For comparisons, I ran the Nebula IV alongside my crappy little Danelectro Chicken Salad and the "Script Phase" and Univibe models from my Line 6 M9. Everyone knows that the Chicken Salad brings a ton of tone with its diminutive price tag and it sounded pretty good next to the Nebula IV. But as Mrs. P90 pointed it, it sounded noisy and a little distracting in comparison. The grit of the Chicken Salad is cool at times, but I found I could place the Rook in front of the Nebula and approximate the grit of the Chicken Salad. As for the comparisons with the M9 (of which I happen to love for modulations) the Nebula IV had a certain thickness and 3-dimensional feel that the M9 lacked. I don't think it's something a listener would pick up on, but it felt different to play. Then again, that's often the case of comparing a real analog pedal to a digital model.
And because I always like to push pedals to places they weren't meant to go, I decided to see what would happen if I cut the amount of voltage supplied to the pedal. In this case it didn't do much. It wouldn't do any phasing at all. However, when the voltage was cut back to around 5 volts, the pedal put out a great sputtery and sad little fuzz tone. It certainly wasn't an amazing fuzz tone, but I could see it having a place in a song.
In short, the Nebula IV is one of the better phase pedals I've played in recent years (maybe ever). It's versatile, easy to dial in, and just plain great sounding. The only improvement I can imagine is adding a jack so that you could control speed with an expression pedal.