Yamaha DTXpress/DTXplorer/DTXtreme

I have assembled the "cheap DTXpander" circuit that Keith posted to 
this site recently and have had partial success with it.
A mono trigger wired to input J3 plays the "pad" sound fine. 
My problem is with input J1 and it's related circuitry: a mono trigger 
wired to input J1 will only play a "rim" sound on a hard hit, on a soft 
hit it plays the "pad" sound. Naturally, I want J1 to play the rim 
sound all the time, and with at least some dynamic range. Tweaking my 
DTX 2.0 brain did not help.
If anyone out there has tried this neat little circuit with different 
results, or has any ideas on circuitry modifications, please post.
Thanks
Phil
P.S. Many thanks, Keith, for your hard work.