The "SID Symphony II" cartridge is now available, and can be found on the Digital Audio Concepts website (http://digitalaudioconcepts.com), along with the internal stereo SID board and my prototyping cartridge board.

The SID Symphony II can be mapped into any 32-byte slot from $DE00 to $DFE0, and should be work fine alongside most other hardware expansions.  Works with all stereo-aware software that can address a SID in the above range.  It is possible to add a jumper to the cartridge to pick up other page address signals inside the computer (such as $D7xx in the C128).

Each board features an access LED, reset button, and a proper 12v DC-to-DC converter for use with the good old 6581 SID chip.  Each board comes preset for $DE00, which can be changed by flipping one or more DIP switches.  The audio-in line is grounded by default to reduce background noise, which one can undo by simply cutting a jumper pad.

The SID Symphony II is supplied without a SID chip, and is designed to fit into standard Commodore-issue case shells and their clones.

$39.95 each, plus shipping

This is a limited edition run, so as the old trope goes, "Hurry, while supplies last!"
:-)