soundsmith makes replacements... however, i do not believe they make an SP style replacement ;-( sorry... (adapters w/ a 20e or later mmc style anyone???)
you can peruse thru ebay -originals come up now and again.
i think you may be better off finding someone on here that may have a known good one available and test it for you, in fact -i may have a sealed NOS one if i recall!
regardless, with their advancing age -it can be hit or miss -even a sealed perfect one can be shot...
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i just found out on researching another thread -that soundsmith may repair SP cartridges!
take a look here
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