I just happened to stumble across these crossovers on eBay (item no. 152390913172, sold by Partyprosound Audio Services, located in Mesa AZ (480) 217-8325)), $99 each, no affiliation), and I called the company up and spoke with the fellow who designed and had them built.
He lists these specs:
- 3 way crossover network system
- crossover frequencies 1.2khz & 8khz
- 12db/oct
- 500 watts RMS / 1000 watts peak
- to use with 8 ohms drivers
- built and based on the " modified version of the "JBL L 300 "
- Metallized Polyester Film capacitors
- 250 volt heavy duty capacitors
- orifices built on board for tweeter&mid for L Pad easy installation
- dimensions 4 3/4" X 6 3/4"
I wound up buying a pair off him for $185 shipped to CA. I've just gone through them and, sure enough, they follow the Nelson Pass schematic shown here (http://www.firstwatt.com/pdf/art_l300.pdf).
Pretty cool. I might upgrade them a bit (outboard, upgraded biased caps, Mills resistors and better coils), but I like the idea of plus and play crossovers. I wonder if these "Bugle' caps are any good? I'm trying to convince them to sell the PCBs, unpopulated, for enthusiast use. They are considering it.
Eric