Very curious what you think about the neutrino
Haven't had a tone of time with it honestly. I've been so busy with day job and playing music (the kind that doesn't really want a filter)!! I have played it some at the house and done quite a bit of A/B testing with the proton, and even some A/B/C testing with the Micro Qtron in the mix. It's a cool pedal - just haven't had an opportunity to play it on a gig - but I can tell it's the real deal and will do just fine. Design is great. Nice build, small enclosure and it runs on a 9V - I really like having the 9V option.
The sound is in the same family as the proton, but it has it's own thing going on for sure. Pretty much has the same features as the Proton but has three filters - low, band pass, and high. Proton only has low and band/high,, can't remember which. Both have a range switch, and a filter up/down switch. Both have a gain, and a peak control. The Neutrino has a bit of a wider range of sound than the proton to me. The low filter with the range on low is a bit deeper than the proton. The low filter with the range up on the neutrino sound great. The BP has some pretty cool sound on the neutrino as well.
The quack of the Proton is pretty natural and organic sounding to me - vs. something like the MXR that has more of a space laser sound. The Neutrino can venture into the space laser sound, but in a very nice organic way - even I kind of like it. It can also do the more natural thing that the proton can do. The Peak control on the Neutrino has a little more juice than on the proton, meaning, it's easier to dial in those big resonant frequencies - this can be a little over the top on some of the low filter settings, but very useful for some other sounds like when using the BP filter for example. The proton is just so smooth to me and it's easy to find a good sound. The neutrino is pretty much the same, but you can dial in some big nasty stuff that is harder to find on the proton - but again, that lends itself to more useful settings in other departments for the neutrino.
One big difference between the two is that he gain on the Neutrino acts like an actual gain control... On the the Proton, you can kind of run the gain all over the place and get a bunch of different responses, but you volume level stays pretty consistent throughout the whole knob. On the Neutrino, once you start getting up past the 2:00ish area, you start getting a good volume increase to go along with the changing response of the filter. Might be a good thing in a live setting as the filter tends to thing out at those higher gain settings.
Overall a very cool pedal with great sounds. Like I said, it has more different sounds than the proton, and they all sound really good. Neutrino is the real deal IMO. I think the proton is a bit more transparent sounding, but the Neutrino is by no means over processed.