Thank you for posting the Neutron, RG !

[petemoore]

  I'd looked it over for many years, thank you for suggesting it's about time I try it years ago.
  I finally did ! Not that I get it, but the tutorial seems to explain any questions I have about it, and building it helped me to understand a little better how it works.
  I'll read through more times in times to come...
  One slick design, I'm glad you chose to 'Neu-ize' the classic and compact HP, LP, BP filter design !
   Now I have a fully operational Neutron though, totally worth it, mesmerizing, having the 'other two' filters one switch away is cool, the range switch adding even more fun to the pots which are also fun to play around with.
  The 3-way output switch I got out of an old Radio thing, the other switches are heavy duty toggles...Beefy !
  I used RS Green LED's, and the Medium [sized closest to LED's] Cadmium Sulfide cells from the multipack. Grabbed a 1meg, and 100k linear and that's working out fine, none exactly matched, all seem to work just great.
  Abso-Dark really helps, any light is noticable if there's a leak in the light can.
  I don't know how sensative it is to capacitor tolerance, one of the switch settings has mismatched .0018 / .0022uf's [feedback filtercaps], film and carbon, seems to like it just fine, I may get around to matching closer these caps as time rolls along.
  The ramp rates of bright/dim are controllable with the input gain to some degree, as well as fuzz for compression to control the ramp rates, perhaps 1 of the components at the '330ohm cluster-node [4u7 cap] would be a good target to get a moddable variation of ramp rate ? Not that I know it needs it, just seems like a good place to maybe get BUM Syndrome.