Trevor, who earlier documented the neck repair of his SB-Elite, now has a great site which documents how he modified the electronics with a varitone filter based on the SB-1000. The catch was that he did it in passive mode. For a step by step look at the process, please check out his site. He includes a schematic as well as sound clips of the results. Trevor says it is pretty safe mod because there's no routing required and therefore you won't permanently alter your bass if you ever want to return to original specs. The bass is a post-Matsumoku Elite which was similar to the originals but with a more simplified control layout. FYI you can see the difference between the two Elite models on Trevor's site. Here is a sneak peak of the mod.
Thanks again to Trevor for documenting this so others may try it or simply see how it was done.
If you want to show off your Aria projects send me the link/pics! I have a feeling there will be some more projects to come, so stay tuned.