This is a tough one. I agree partly with bigblondafro, though I don't think there's any phaser- might just be PWM on the square and/or saw. Ive recently been working on tones just like this, and find that PWM on a square has a very audible phasing/flanging sound, much more so than with a saw or triangle, and it sounds very similar to this track. When I get a 2nd Freqbox I'll
really be able to nail this tone, but right now I can get very close by running an OC-2 into the Freqbox with a Saw and PWM in parallel with the Pollyanna square -1oct, into the Photron or MoogLPF (photron is voiced better) manually controlled with my foot (easiest way to nail the modulation) into a light flange since i can't get that part of the sound from the Freqbox yet (when I get the 2nd Freqbox, I wouldn't use flange, just PWM on a square in place of the pollyanna).
In short, its not cheap or easy to get the tone in the video, and even with all the right gear there is still a fair amount of programming and experimenting involved in getting the presets made and everything dialed in.
To get close enough for rock&roll/cover band, the cheapest way I could think to do it would be a Boss SYB-5 or Beringer BSY using the sawtooth mode and manually sweeping its filter, with a flanger set to a very slow sweep and low resonance. It would take some practice to get the tracking and modulation with your foot spot-on, but I think it would be very doable with good technique and a bit of practice; an eq and/or compressor placed before the SYB may help with the tracking. Its been a long time since I had the Boss SYB-3, but I really think that it is capable of tones that are very close to what we're hearing in the video, especially with a little modulation after it.
Im not sure how the manual filter feels or really sounds on the SYB5 as I've never used it, but if you had a little trouble with tracking on attack of each note but otherwise like the sound, you could probably mask any deficiencies and still get very close to the tone with a MoogLPF or similar: on the attack of each note, close the filter all the way or most of the way, and then quickly open it up and back to following the songs modulation; doing this closes the filter when the tracking glitch occurs, so you still feel the bass hit but don't hear the glitch, and a split second later you have the filter back open with a clean sawtooth under it. Sure this is a little different than how the filter moves in the song, but if you do it quickly it is hardly noticeable.. and works great!
It would be worth trying this technique, if necessary, with the SYB and an exp pedal first- I mentioned the MoogLPF because Im not sure if the SYB's filter tone glitches when a glitch occurs in one of the octave/synth modes or not; if it doesn't, then it may work just the same.
