Vintage Simmons Drums (UK) Users Group

Just thought I could share my latest Silicon Mallet events for anyone 
interested in this beast.
I acquired it with its 20 presets intact but 80 empty user-patches. 
The manual lists the 80 exciting patch names which represent sounds 
installed at the factory, but these have subsequently been lost. I 
don't have much twiddling time, but have created a couple of bass 
type sounds, which seem to store ok, not sure how this is achieved. 
I did notice a remarkable similarity between the Mallet's control 
panel and 
the SDE. Both have 6 voices and near identical knob layout. I've now 
successfully added the SDE to the Mallet as an expander, but with 
MIDI I can also mix sounds from one with the other. The SDE's presets 
offer a varied sound-set since they were I think intended for drums, 
rather than tuned percussion, but most work well, and also receive 
pedal data from the Mallet. I'm now hunting for the ROM or RAM 
cartridges which expand the SDE memory still further and slot in on 
the right end of the panel. If anyone out there has one, or even just 
the circuit for one, I'd be very interested. My hunch is that the 
cartridges might easily be constructed. In fact, I wonder if they are 
similar to a Psion II Organiser's "Rampack" (remember them?). 
Essentially just an SRAM and battery, or an EPROM for a ROM pack.
The Mallet suffers from 3 problems. 
1/ Locks up after 20 minutes on. Suspect this is a dry joint in the 
power supply which gets quite warm.
2/ High note sounding when keyboard is struck anywhere. I think there 
is a poor track repair in the sensor tracks under the keyboard top 
octave, but I should be able to cut it out with a scalpel
3/ Locks up when moved. Tricky; a connection problem between control 
box and keyboard, perhaps; I'll see what happens after dismantling it 
for fault 1.
Other than these, a fine and unique sound generator. I hope it'll be 
roadworthy some day.
Stay tuned!

Paul