The main room electronics consist solely of a Harmen-Kardon AV20 mk II surround sound receiver, along with a Pioneer ? six-disc magazine CD changer. These components are connected to the custom active crossover/line amplifer unit detailed on the schematics page. The main speakers in the gathering room are Design Acoustics PS-10s (remember those?). The subwoofer is driven by an Adcom GFA-535.

  The downstairs system consists of a Teac (model?) surround sound receiver, Radio Shack LX-5 Pro satellites and some 8" two ways salvaged from a burned-out Grundig unit a few years back. There is also a Hi Fi VCR and a satellite receiver unit attached to this system, feeding a Mitsubishi 35" rear-projection TV. A nice place to watch movies, but it really needs a sub. My wife says no. ;-)

Custom Electronics

  The gathering room unit is by far the most complex, containing both the active crossover for the main room system plus the line drivers for the low level wiring distributed throughout the house. It was an exersise in miniaturization; the purpose for this is lost in the murky depths of time, but let's just say I didn't finish cramming when I finished college. The auxilliary filter for the 6th order sub, and the 4th order LR crossover, are each mounted on separate breadboards that can be unplugged from the main board. All wires to the main board are run through connectors so that the system can be completely disassembled for troubleshooting or upgrading.

  When I first built this unit, I attempted to use breadboard and simple jumper wires to complete it. When I got about four or five layers deep in hookup wire and discovered a mistake at the bottom, I decided it was better to do a PC board. So, I bought plastic film, layout tape & decals, light-sensitive PC board and all the nifty chemicals that go with it. After a second shot, I got a working board. There was only one connection overlooked in the design, which I'm still proud of to this day. I still have the transparency used to burn the design onto the board.

  The downstairs unit is much simpler, containing just five line drivers with unity gain and a single opamp with gain and a volume control.

  The nook volume control has an interesting hodgepodge of components hanging off the back to perform the simple task of controlling on/off and volume. It, too, is built with connectors to allow it to be removed from the wall easily.