1 Toxophilite 11 months ago Having handwound a filtertron pickup from a kit a while back and also having recently heard that the new Blacktop filtertrons actually have alnico magnets. i thought I'd have a bit of forensic fun. Apologies if this is commonplace knowledge.All three pickups seem to have shiny alnico magnets. The HS filtertron has a 1/4" and the others are 1/8" thick Basic construction is very similar with the kit being almost identical to the HS though admittedly I used medical tape to wrap the windings and leather strips to support the sides of the coils. The BF coils are slightly taller. They all measure about the same. I'm betting the magnet size difference will be the biggest one between these pickups, I haven't tried them back to back though I'm sure others have. I'm actually kind of partial to the blackface ones though I've never tried the HS ones.