If you want a solid, effective, and versatile modulation pedal, the Bubble Tron is made for you. Supposed to replicate the dynamic phaser and flanger of the Mutron used by Frank Zappa combined with a sample and hold filter, it is a superb tool to sculpt your sound with finesse. It seems that the dynamic flanger and phaser are quite rare. The advantage is that the effect intensity increases with the attack of the strings, so there is no constant "swoosh" behind like on usual phasers/flangers. Moreover, the flanger can do positive or negative feedback. The filter is not dynamic but the knob at the bottom left allows you to adjust the waveform type (sawtooth or random). The big plus is that what I just described is mode 1 (filter, dynamic phaser, and dynamic flanger) but by opening the pedal you can use mode 2 which includes an envelope filter, a classic phaser, and flanger (non-dynamic). It's a pity you can't change the mode without opening the pedal. Finally, there is another small switch inside for vintage or modern voicing. Personally, it doesn't bother me because I mainly use mode 1 (that's the point of having dynamic phaser/flanger) in modern voicing. A bit of time to understand the settings if you are a beginner but basically, it's not very complicated. It's a solid, reliable, very versatile pedal while having quite simple settings in the end. It's honestly my favorite pedal, quite simply.